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HP 8673D User's Manual

1. 3 41 Receiving the Abort Message 05 3 41 Detailed Operating Instructions 00 3 45 Amplitude Modulation 0000 3 46 Anto Peak osora nena ea iae eens eereeeeet 3 49 Auto Sweep Mode cece cece ee ceeee eens 3 52 Center Frequency Sweep e 3 56 Delta Frequency Sweep 3 60 Diode Automatic Level Control 3 64 y Contents HP 86738C D CONTENTS cont d Page Page Dwell Time Sweep 0 eee reece eee 3 68 Performance Test Record cce cece reenees 4 1 Frequency CWT we 3 70 Equipment Required wi soe fawn Shae deeaes 4 Frequency Increment and Tuning 3 76 Pest Procedures voorirrcuni te teers pass ideniaeeda 4 1 Frequency Modulation 0 02 0 eee eee es 383 Abbreviated Performance Tests eee 4 2 Internal Automatic Level Control 3 86 Turn O Checks 2 uwe e se cis edens dep RE 4 2 Manual Sweep Mode annnanaanonannanno 3 89 Frequency Range and Resolution Test 4 8 Marker Frequency Sweep 5 ee 3983 Output Level and Flatness Tests 4 5 Master Slave Sweep 0c c eee HT Level Accuracy Tests 0 ccc cece cence eee 4 9 Messages courreguerian Weds a ORE MARES 3 100 Pulse Modulation Test cece eee 4 12 Multiplier Mode s oved oastedcinneweds 3 102 AM Accuracy Tosta cece ccc cc cee teeetees 4 16 Normal and Bypass Modes
2. 2 006 3 105 External FM Accuracy and Meter Accuracy 4 18 Offset Frequency edi ehssaseanseewe wee 3 107 Frequency Range and Resolution Test 4 23 Power Meter Automatic Level Control 3 110 Internal Time Base Aging Rate 005 4 26 Pulse Modulation ccw Nd oadvecws eease ct 3 116 Frequency Switching Time Test 4 28 Range Output Level ccs ence se cenees 3 119 Single Sideband Phase Noise Test 4 35 Recall and Store Registers 005 3 122 Harmonics Subharmonics amp Multiples RE Output Ca OE agg R R R toads ee 3 125 CHES R soaks ER 4 40 Single Sweep Mode p a 200 eee 3 127 Non Harmonically Related Spurious Signals Start Frequency Sweep 00ce eee eee 3 131 CW and AM Modes egite 4 42 Status Byte and Polling 0005 3 187 Power Line Related Spurious Signals Tests 4 44 Steps Sweep ccc cer ecce ec ceeenetens 3 144 Output Level and Flatness Tests 04 4 48 Step Size Sweep ei ccs sw hdiewe aod sesa vera 3 147 Absolute Level Accuracy Tests 005 4 52 Stop Frequency Sweep 00 eevee 3 150 Output Level Switching Time Test 4 59 System Automatic Level Control 8 156 Pulse On Off Ratio Test coc cen cei sk asde rarere 4 64 Vernier Output Level ccc eee c ee eeeee 3 159 Pulse Rise Fall Time and Overshoot Test 4 66 Pulse Peak Level
3. PULSE MODULATION TEST cont d Procedure 9 cont d Switch back to PULSE NORM The display should be as shown in Figure 4 6 Measure the difference between the CW peak reference level and the average peak pulse level excluding any over undershoot Record the peak level accuracy NOTE The error can be read in percent Using 5 divisions for the CW peak reference each division represents 20 error Measured error must be within the limits of 15 8 0 8 division and 18 8 0 9 division on the oscilloscope display This is equal to 1 5 dB peak level accuracy Peak Level Accuracy 50 MHz 15 8 L18 R ON OFF Ratio at 50 MHz and 6 7 GHz 10 11 12 13 14 15 16 17 18 19 Disconnect the RF output from the 10 dB attenuator and amplifier Connect the Signal Generator to the input of the spectrum analyzer as shown in Figure 4 4 Press the PULSE OFF switch on the Signal Generator Adjust the spectrum analyzer to display the 50 MHz CW signal so thatthe peak ofthe signal is at the top of the display The resolution bandwidth should be set for 300 Hz or less and the span to to 20 kHz or less to reduce broadband noise Disconnect the pulse generator signal from the Signal Generator PULSE IN Press the PULSE NORM switch The signal level should be at least 55 dB below the reference established in PULSE OFF mode ON OFF Ratio 50 MHz 7 BD db Change the Signal Generator frequency to 6
4. Program Suffix Program Code Description Sweep Marker MO Off Commenis Each marker that is activated adds a frequency point to the sweep If the marker frequency already exists in the sweep an additional frequency will be added to the sweep and will occur before the existing frequency When the marker frequency is generated the BLANKING MARKER and TONE MKR signals are activated to provide markers on the external display The next frequency in the sweep will be the same RF frequency except that the two rear panel marker signals are turned off This feature allows the marker to be used to mark the display while still being able to observe the response at the marker frequency without the marker signals present 3 95 Operation HP 8678C D Detailed Operating Instructions Comments contd Programming Example Error Messages 3 96 Marker Frequency Sweep conra During a sweep where the marker is set to an existing sweep point the marker fre quency is always generated first unless the marker frequency is set to the start frequency For a marker that is set equal to the start frequency the first generated fre quency will be the existing sweep point and then the marker frequency will be generated Connecting the TONE MKR rear panel output to the Signal Generator s AM IN con nector provides amplitude markers for a spectrum analyzer display The RF output is modulated at a 5 kHz rate with approximately 25 or
5. 3 45 Operation HP 8673C D Detailed Operating Instructions Description Locai Procedure Remote Procedure Example 3 46 Amplitude Modulation The Signal Generator provides linear amplitude modulation when internally leveled or when externally leveled with a power meter External leveling with a diode detector requires that the diode is operating in the square law region to provide linear amplitude modulation The Signal Generator has a selectable sensitivity of 30 AM per volt or 100 AM per volt AM depth is linearly controlled by varying the AM input drive level between 0 and 1 volt peak into 600 ohms For example 0 5 volts peak will develop 15 AM depth on the 30 range and 50 AM depth on the 100 range AM depth is monitored using the Signal Generator s front panel meter in the AM meter mode The meter monitors the signal at the AM input connector and displays the corre sponding AM depth in percent An overmodulation condition is indicated by the ALC UNLEVELED annunciator when the modulation depth exceeds the Signal Generator capability To set the Signal Generator to a desired AM depth 1 Press the 30 or 100 AM range key Ifthe desired depth is less than or equal to 30 use the 30 range for better display resolution Otherwise select the 100 range The key indicator should light when the key is pressed to indicate which range is selected C Connect an external oscillator to the AM input and set t
6. HP 8673C D Remote Procedure cont d Example Program Codes gt Comments Operation Detailed Operating Instructions Delta Frequency Sweep conta The format of the remote programming follows the front panel key sequence To program the sweep delta frequency the program code DF is sent followed by the desired frequency and the units GZ MZ KZ or HZ The current sweep delta frequency can be read by the controller using the output active program code suffix To read the stop frequency send the program codes DFOA and then read the delta frequency The Signal Generator will send the frequency in fundamental Hz units If the frequency is read as a string the format will be the program code DF followed by the sweep stop frequency in Hz and then the units terminator Hz To set the sweep delta frequency to 4500 MHz Local 1 Press the SWEEP FREQ AF key 2 Key in 4500 using the numeric keypad The FREQUENCY MHz display should show 4500 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the MHz units key to finish the sequence The FREQUENCY MHz display should show the entered frequency until the units key is released The FRE QUENCY MHz display should now be right justified The frequency could also have been entered as 4 5 GHz or 4500000 kHz The only difference is the placement of the decimal point and the units key pressed after the frequen
7. NOTE Connect the mixer directly to the local oscillator to avoid any power loss 2 Set the Signal Generator as follows FREQUENCY ci tscnsecesdsaduaveutyss 2 GHz OUTPUT LEVEL RANGE 0dB OUTPUT LEVEL VERNIER 5 dBm FM DEVIATION range 55 0 3 MHz Meter Seale oo eeseun se eee es FM Tune the local oscillator to 2 5 GHz with an output amplitude of 8 dBm Set the measuring receiver to measure FM Set the test oscillator to a 100 kHz rate Adjust the test oscillator output level to obtain a full scale reading on the Signal Generator s front panel meter 6 Themeasuring receiver should read 300 kHz 45 kHz deviation Record the reading 255 kHz mm 345 kHz HP 8673C D Performance Tests ABBREVIATED PERFORMANCE TESTS EXTERNAL FM ACCURACY AND METER ACCURACY contd Procedure 7 Adjust the test oscillator level to obtain 50 kHz deviation as read on the Signal cont d Generator s front panel meter 8 The measuring receiver should read 50 kHz 15 kHz deviation Record the reading 35 kHz 65 kHz Accuracy Relative io External FM Input 9 10 11 12 13 14 Tune the test oscillator to 100 kHz with an output amplitude of 0 707 Vrms as read on the digital voltmeter Set the Signal Generator FM DEVIATION range to 0 03 MHz The measuring receiver should indicate FM deviation within the limits listed in the table below Record the reading in
8. 2 00 dB 3 50 dB 4 51 Performance Tests HP 86738C D PERFORMANCE TESTS 4 16 ABSOLUTE LEVEL ACCURACY TESTS Specification l Electrical Performance Characteristics Characteristics Conditions Output Level Remote Programming 2 0 to 6 6 GHz Absolute Level 1 25 dB 10 dB RANGE Accuracy 15 to 1 00 dB 0 dB RANGE 35 C 1 50 dB 10 dB RANGE 1 70 dB 20 dB RANGE 2 00 dB 30 dB RANGE 2 00 dB amp lt 30 dB RANGE 0 1 dB 10 dB step 6 6 to 12 3 GHz 1 50 dB 10 dB RANGE 1 25 dB ae 0 dB RANGE 1 75 dB 10 dB RANGE 1 95 dB 20 dB RANGE 2 25 dB 80 dB RANGE 2 25 dB amp lt 380 dB RANGE 0 1 dB 10 dB step 12 3 to 18 6 GHz 1 75 dB 10 dB RANGE 1 50 dB 0 dB RANGE 2 10 dB 10 dB RANGE 2 80 dB 20 dB RANGE 2 70 dB 30 dB RANGE 2 70 dB amp lt 30 dB RANGE 0 2 dB 10 dB step HP8673D 18 6 to 26 0 GHz 2 25 dB 10 dB RANGE 2 00 dB 0 dB RANGE 2 55 dB 10 dB RANGE 2 85 dB 20 dB RANGE 3 30 dB 30 dB RANGE 3 380 dB amp lt 30 dB RANGE 0 2 dB 10 dB step Absolute level accuracy specifi Manual Absolute Add 0 75 dB to cations include allowances for Level Accuracy remote programming detector linearity temperature absolute level accuracy flatness attenuator accuracy and measurement uncertainty Description This test checks absolute level accuracy of the RF output signal The first test uses a power meter to verify that po
9. 4 Set the OUTPUT LEVEL RANGE to 10 dB Adjust the VERNIER for a power meter reading of 11 0 dBm 5 Peak the Signal Generator output with the AUTO PEAK key 6 Set the power meter to dB Relative 4 53 Performance Tests HP 8673C D PERFORMANCE TESTS ABSOLUTE LEVEL ACCURACY TESTS cont d Procedure 7 cont d 10 Il 12 13 14 15 16 17 18 19 Adjust the VERNIER for an output amplitude of 11 dBm 1 dB front panel meter indication Tune the Signal Generator from 0 05 to 2 0 GHz in 100 MHz steps while noting the power meter readings at each frequency step Do not readjust the VERNIER The power meter readings should be within the limits specified 0 05 2 0 GHz 2 00 dB 2 00 dB Tune the Signal Generator to 50 MHz Set the power meter to dBm mode Adjust the VERNIER for a power meter reading of 5 0 dBm Set the power meter mode to dB Relative Adjust the Signal Generators VERNIER for an output amplitude of 5 dBm 5 dBm front panel meter indication Tune the Signal Generator from 0 05 to 2 0 GHz in100 MHz steps while noting the power meter readings at each frequency step Do not readjust the VERNIER The power meter readings should be within the limits specified 0 05 2 0 GHz 2 00 dB 2 00 dB Tune the Signal Generator to 2 0 GHz Set the NORMAL BYPASS switch to NORMAL Tune the Signal Generator from 2 0 to 6 6 GHz in 1 GHz steps while n
10. Detailed Operating Instructions Local Procedure Contd Remote Procedure Example Program Codes gt Comments 3 90 Manual Sweep Mode conta Direct entry of a frequency using the numeric keypad will change the center frequency of the sweep This will reset the start and stop frequency and set the current frequency equal to the new start frequency The FREQ INCREMENT keys and the TUNE knob will tune the frequency between the start and stop frequency The FREQ INCREMENT keys and the TUNE knob will always operate just as in CW mode Setting the start frequency above the stop frequency will place the frequency at the higher start frequency when manual sweep is activated however counter clock wise rotation of the TUNE knob and the FREQ INCREMENT down key will always decrement the frequency whether the start frequency is set above or below the stop frequency Manual sweep mode is activated with the program code W3 The sweep can be reset with the program code RS Resetting the sweep will reset the sweep frequency to the start frequency The IF program code will produce a step toward the stop frequency even if the start frequency has been set above the stop frequency The UP program code will always produce an increase in the absolute frequency and DN will always produce a decrease in the absolute frequency The output couple OC program code can be used to read the start frequency center frequency and dwell time i
11. Programming Example Error Messages Operation Detailed Operating Instructions Range Output Level conra The 0 to 90 dB ranges directly control a 90 dB step attenuator The 0 and 10 dB ranges correspond to an internal attenuator setting of 0 dB The 90 dB range corresponds to an attenuation setting of 90 dB The 10 dB range is used by the automatic level control ALC circuitry to enable the VERNIER to directly control the RF output level between 0 dBm up to a maximum possible level of 13 dBm The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program will set the output level between 100 and 13 dBm Ifa level above 0 dBm is set and is not leveled an error will be reported 10 SUB Rf_level Err Expected Expected is in dBm 20 30 If Expected lt 100 OR Expected gt 13 THEN 40 Err 4 50 DISP ERROR Requested output level is out of range 60 SUBEXIT 70 END IF 80 90 OUTPUT 719 USING 2A MG T Clear old messages 100 ENTER 719 USING 2A Message 110 120 OUTPUT 719 USING 4A 4D D 2A CSLE Expected DM Set the level 130 140 OUTPUT 719 USING 4A LEOA 150 ENTER 719 USING K Level 160 170 IF ABS Level Expected gt 1 THEN More than 1 dB in error 180 Err 1 190 DISP WARNING Programmed level is more than 1 dB in error 200 END IF 210 220 V SPOLL 719 Get the status byte 230 IF NOT BIT V 3 THEN
12. SH1 AH1 T5 TEO L3 LEO SR1 RLI PP1 DC1 DT1 Co E1 0 to 55 C except specifications for harmonically related spurious signals RF output pulse peak level accuracy and amplitude modulation which apply 15 to 35 C 5 10 4866 Hz 500 V A maximum MIL STD 461A 1968 Conducted and radiated interfer ence is within the requirements of methods CE03 and RE02 of MIL STD 461A VDE 0871 and CISPR publication 11 42 3 kg 94 Ib For ordering HP cabinet 234 mm 9 2 in accessories module sizes are 425 mm 16 8 in 8H 1 MW 23D composed of 620 mm 24 4 in two parts 3 2 in high and 5 in high HP 86738C D General Information Table 1 2 Supplemental Characteristics 1 of 3 Supplemental characteristics are intended to provide information useful in applying the instrument by giving typical but non warranted performance parameters They apply to the HP 8678C D in Normal mode CW operation and with AUTO PEAK on except where noted FREQUENCY Internal Reference The internal reference oscillator accuracy is a function of time base calibration aging rate temperature effects and line voltage effects Typical temperature and line voltage effects are lt x 10 10 C and lt 5 x 1071 5 to 10 line voltage change Reference oscillator is kept at operat ing temperature in STANDBY mode with the instru ment connected to mains power For instruments disconnected from mains powe
13. Tune the Signal Generator in 50 MHz steps from 50 0 MHz to 2 0 GHz while observ ing the power meter reading Record the frequency at which minimum power occurs Frequency Tune the Signal Generator to the recorded frequency Adjust the VERNIER for a power meter reading of 11 dBm Tune the Signal Generator from 50 0 MHz to 2 0 GHz in 100 MHz steps while observ ing the power meter readings Ensure that the specified maximum leveled output power level is met Tune the Signal Generator to 2 0 GHz Set the NORMAL BYPASS switch to NORMAL Adjust the VERNIER for a power meter reading of 5 dBm Tune the Signal Generator in 100 MHz steps from 2 0 to 16 0 GHz while observing the power meter readings Record the frequency at which minimum power occurs Frequency Tune the Signal Generator to the recorded frequency Adjust the VERNIER for a power meter reading of 5 dBm Tune the Signal Generator from 2 0 GHz to 16 0 GHz in 100 MHz steps while observ ing the power meter readings Ensure that the specified maximum leveled output power level is met Tune the Signal Generator to 2 0 GHz Set the NORMAL BYPASS switch to BYPASS Adjust the VERNIER for a power meter reading of 8 dBm Tune the Signal Generator in 100 MHz steps from 2 0 GHz to 16 0 GHz while observing the power meter readings Record the frequency at which minimum power occurs Frequency Tune the Signal Generator to the recorded frequency Adjust the VERNIER
14. cx ee 3 27 Abort Message ccc cncccucceeersrecuen 3 27 Status Byte Message ccc ccc e eee 3 27 Require Service Message 0 ee eee eee eee 3 28 Status Bit Message 0 cece eee eee ee 3 28 Trigger Message 60k iis ewe sien sanaccweewers 3 29 Remote Operation Auxiliary Control 3 31 AUX Input Lines sss e e e ee seen ee ee es 3 31 AUX Output Lines eee 3 31 Remote Operation HPB 3 32 HP IB Compatibility ccseee eae 3 32 Remote Mode Nhat 3 32 Local Mode 20 064 es0iaus Vabsos ik eke iver antes 3 32 Addressing evs ou tiat Beye bos a wdsy 3 34 Turn on Default Conditions 3 385 IR yi eceran a sushwar cada dena a a 3 35 Output Level sss ee ee gepeye 3 35 Data Messages Pee rr eee Receiving Data Messages 3 35 Sending the Data Message 0 0008 3 36 Receiving the Clear Message 0005 3 39 Receiving the Trigger Message 3 39 Receiving the Remote Message 64 3 39 Receiving the Local Message 23 39 Receiving the Local Lockout Message 3 39 Receiving the Clear Lockout Set Local Message art este cantecnesecuie eee een 3 39 Receiving the Pass Control Message 3 40 Sending the Require Service Message 3 40 Sending the Status Byte Message 3 40 Clearing the Status Byte 0 0 0 0 eee 3 40 Sending the Status Bit Message
15. 6 0 GHz 6 0 GHz A tracking bandpass filter is switched in from 6 to 22 GHz 18 6 for the HP 8673C to reduce harmonics and subharmonics above 6 6 GHz 16 0 GHz An amplifier is switched in to increase output power above 16 GHz HP 8673D only 22 0 GHz A high pass filter is switched in to reduce subharmonics HP 8673D only Programming The following programs are written in BASIC for HP 9000 Series 200 or 300 controllers Example The following program is used to set the Signal Generator to the frequency specified by the variable called Expected The desired value must be in MHz and should be within the frequency range of the Signal Generator 10 SUB Freg_set Err Expected Expected frequency in MHz 20 OUTPUT 719 USING 2A MG I Read message from 8673 30 ENTER 719 USING 2A Message to clear any old messages 40 Frequency INT Expected 1000 1000 Round off to nearest kHz 50 OUTPUT 719 USING 4A 5D DDD 2A CSFR Frequency MZ T Update status 60 CALL Settled Wait for source to settle 70 OUTPUT 719 USING 2A MG Check for message from 8673 80 ENTER 719 USING 2A Message 90 SELECT VAL Message 100 CASE 1 Frequency was out of range 110 Erre 120 DISP WARNING Attempt to set frequency out of range 130 CASE 90 Auto Peak Error 140 Err 90 150 DISP WARNING Auto Peak error Service may be required 160 CASE ELSE 170 Err 0 Other errors not applicable 180 END SELE
16. CA 60 sepr age eao 290090238 S frequency standard of 5 or 10 MHz at 0 dBm to the Signal Generator FREQ STANDARD INT EXT Switch Normally left in the INT position Removes power from internal fre quency standard when in the EXT position Line Power Modules Permit operation from 100 120 220 or 240 Vac The number visible in the window displays the nominal line mains voltage for which the module is set see Figure 2 1 The protective grounding conductor connects to the Signal Gen erator through this module The line power fuse is part of this module and is the only part to be changed by the operator amp 108 MHz OUT A3J7 0 dBm nominal into 500 Reference frequency connected to Ad5J1 to phase lock internal circuits EE Jumper W60 Connects the 100 MHz reference output A3J7 to the reference input A5J1 15 100 MHz REF INPUT A5J1j Connected to A3J7 by W60 to phase lock internal circuits 16 BLANKING MARKER BNC female connector Output impedance is 100Q nominal Provides 5V at the beginning of each frequency change for blanking a swept display to eliminate display of switching transients Goes to 5V during remainder of fre quency step for Z Axis intensity marker or to OV for non marker frequencies AUX Connector Allows remote control of frequency increment display blanking register recall and start and stop sweep Refer to Table 3 3 AUX Connector Functions for additional information
17. Fall Overshoot and Ringing 17990 003 MHz at 10 dBm Rise Fall Overshoot and Ringing 18590 004 MHz at 6 dBm Rise Fall Overshoot and Ringing 4 100 HP 8673C D Performance Tests Table 4 4 Performance Test Record 11 of 13 Results i Min Actual a ae eas H 18590 004 MHz at 0 dBm Rise Fall Overshoot and Ringing 4 19 PULSE RISE FALL TIMES AND OVERSHOOT contd 18590 004 MHz at 10 dBm Rise Fall Overshoot and Ringing 18600 004 MHz at 6 dBm Rise Fall Overshoot and Ringing 18600 004 MHz atOdBm Rise Fall Overshoot and Ringing 18600 004 MHz at 10 dBm Rise Fall Overshoot and Ringing 21990 004 MHz at 6 dBm Rise Fall Overshoot and Ringing 21990 004 MHz at 0 dBm Rise Fall Overshoot and Ringing 21990 0904 MHz at 10 dBm Rise Fall _ Overshoot and Ringing 22000 004 MHz at 0 dBm Rise Fall Overshoot and Ringing 22000 004 MHz at 10 dBm Rise Fall Overshoot and Ringing 25990 004 MHz at 6 dBm Rise Fall Overshoot and Ringing 25990 004 MHz at 10 dBm Rise 9 Fall T i Overshoot and Ringing 4 101 Performance Tests Para No 4 20 PULSE PEAK LEVEL ACCURACY Frequency 1 93 GHz 6 6 GHz 6 61 GHz 12 3 GHz HP 8673D only 18 61 GHz 22 1 GHz 4 21 AM BANDWIDTH HP 8673D only 4 22 AM ACCURACY Meter Accuracy 6 6 GHz 6 6 GHz 6 6 GHz 10 GHz 14 GHz HP 8678D only 18 6 GHz 22 GHz HP 8673C only 18 5 GHz 4 23
18. Figure 4 7 High Frequency Pulse Test Setup Signal Loca Overshoot Generator Oscillator Rise Time and Peak Level Accuracy Frequency Frequency Ringing 6 7 GHz 6 75 GHz 18 BI 12 GHz 12 05 GHz 18 GHz 18 05 GHz HP 8673D 19 GHz 19 05 GHz 4 15 Performance Tests HP 86738C D ABBREVIATED PERFORMANCE TESTS AM ACCURACY TESTS Description Equipment Procedure The Signal Generator is amplitude modulated by an audio source The modulated signal is mixed with a local oscillator to produce a modulated 100 MHz IF signal The AM depth meter accuracy and accuracy relative to the external AM input are iaoa using a measuring receiver Local Oscillator cioivars HP 8340A Measuring Receiver 000 HP 8902A Audio Analyzer Source 0025 HP 8903B Digital Voltmeter eee eee HP 3456A 6 dB Attenuator HP 8493C Option 006 Mixer aaun eure eihde aes arenes RHG DMS1 26 HP 8673C D SYNTHESIZED SIGNAL GENERATOR LOCAL OSCILLATOR AUDIO ANALYZER SOURCE RF OUTPUT MEASURING RECEIVER IGITAL VOLTMETER MODULATION OUTPUT Figure 4 8 AM Accuracy Test Setup 1 Connect equipment as shown in Figure 4 8 2 Set the Signal Generator as follows FREQUENCY vecsecisy vised snenenieegs 1 90 GHz OUTPUT LEVEL RANGE 0dB OUTPUT LEVEL VERNIER 0 dBm PINS aware A ET Satersac dius oe INT AM 9 pica seus dattt aes ewen Ba eee eewhes 100 range PMO coc wne ted be tean t
19. INCIDENTAL FM 4 102 1 kHz Rate 50 AM Accuracy Relative to External AM Input Level 10 dBm 4 dBm 4 dBm 0 dBm 10 dBm 4 dBm 0 dBm 10 dBm 4 dBm 0 dBm 10 dBm 4 dBm 0 dBm 10 dBm 4 0 GHz 6 7 GHz 15 0 GHz 24 0 GHz 26 0 GHz 10 kHz 1kHz 0 1 kHz 10 kHz 10 kHz 10 kHz 10 kHz 10 kHz 200 MHz 1 0 GHz HP 86738C D Table 4 4 Performance Test Record 12 of 13 Results Actual 10 8 18 8 10 8 re 18 8 10 8 etal 18 8 10 8 a 18 8 10 8 soto 18 8 10 8 18 8 10 8 en 18 8 10 8 18 8 10 8 18 8 10 8 18 8 10 8 SR 18 8 10 8 18 8 10 8 ESDA 18 8 10 8 18 8 3 dB 906 3dB 3 dB 3 dB 41 5 y 58 5 79 9 S 100 1 79 9 hd 100 1 79 9 100 1 79 9 100 1 79 9 ae 100 1 79 9 eS 100 1 79 9 100 1 79 9 100 1 lt 4kHz lt 4kHz HD 86738C D Performance Tests Table 4 4 Performance Test Record 13 of 13 Results Actual INCIDENTAL FM cont d HP 8673D only FM FREQUENCY RESPONSE 3 kHz 30 kHz 100 kHz 300 kHz 1000 kHz 3000 kHz EXTERNAL FM ACCURACY AND METER ACCURACY Meter Accuracy Full Scale 255 kHz 50 kHz 35 kHz Accuracy Relative to External FM input 0 03 MHz range 27 kHz 0 1 MHz range 90 kHz 0 8 MHz range 270 kHz 1 0 MHz range 249 kHz 0 3 MHz Range Accuracy 6 7 GHz 270 kHz 12 3 GHz 270 kHz 18 6 GHz 270 kHz INC
20. ccc cece ceenes HP 3585A Mixer L aT Aar N bee Ah aad ie sete anes RHG DMS1 26 Variable Frequency AC Power Supply 501TC 800T California Instruments Procedure 1 Connect the equipment as shown in Figure 4 20 NOTE Connect the mixer directly to the local oscillator to avoid any power loss 2 Place the Signal Generator and the local oscillator on separate two inch thick foam pads 3 Tune the Signal Generator to 1 999 980 MHz 4 Set the OUTPUT LEVEL RANGE to 20 dB Adjust the VERNIER to 0 dBm 4 44 HP 8673C D Performance Tests PERFORMANCE TESTS POWER LINE RELATED SPURIOUS SIGNALS TESTS contd Procedure S cont d HP 8673C D SYNTHESIZED SPECTRUM ANALYZER SIGNAL GENERATOR LOCAL OSCILLATOR SSS OST RAR RRR ESSE SS INPUT RE FOAM PAD RF FOAM PAD OUTPUT OUTPUT M R LO O RF Figure 4 20 Power Line Related Spurious Signals Test Setup 5 Tune the local oscillator to 2000 000 MHz with an output amplitude of 7 dBm 6 Set the spectrum analyzer start frequency to 20 kHz frequency span to 500 Hz and resolution bandwidth to 3 Hz 7 Adjust the spectrum analyzer controls to place the peak of the 20 kHz IF signal on the top graticule line Verify that the line related harmonics of the Signal Generator do not exceed the values shown below Record the highest spurious signal level in each offset band 0 05 2 0 GHz lt 300 Hz offset ___ lt 50 dBe 8 Set the spectrum analyzer frequency span t
21. 110 Err 1 120 DISP Desired AM depth is greater than 100 130 END SELECT 140 150 OUTPUT 719 USING 2A Depth 160 170 SUBEND Error There are no messages associated with the setting of amplitude modulation Messages 3 48 HP 8673C D Description Local Procedure Remote Procedure Operation Detailed Operating Instructions Auto Peak The Signal Generator uses an internal tracking filter for increased spectral purity and for rejecting unwanted multiplication products when generating frequencies above 6 6 GHz Ifthe passband of the tracking filter is off by as little as 10 MHz maximum avail able power is reduced pulse modulation is distorted and the frequency modulation sidebands are filtered asymmetrically The tuning accuracy of the internal tracking filter must be better than 0 1 to avoid these problems Because of nonlinearities hysteresis and temperature sensitivities of the tuning the filter must be fine tuned with an Auto Peak operation to center the pass band of the tracking filter The Auto Peak operation occurs whenever the frequency has changed by more than 20 MHz from the last frequency where an Auto Peak operation was performed An Auto Peak also occurs whenever Auto Peak is switched from disabled to enabled when pulse mode is enabled when an FM deviation range is changed and when the RF output is turned on Pulse modulation requires Auto Peak to be enabled to guarantee the published specifica
22. 330 IF Expected lt 26500 001 THEN Band 4 340 IF Expected lt 18600 001 THEN Band 3 350 IF Expected lt 12300 001 THEN Band 2 360 IF Expected lt 6600 001 THEN Band 1 370 380 Baseband INT Expected 1000 Band 1000 Rounded fundamental 390 Round_down Baseband Band 400 IF Round_down lt gt Expected THEN Requires rounding 410 Round_up Baseband 001 Band 420 IF ABS Round_down Expected lt ABS Round_up Expected THEN 430 Expected Round_down Minimum error is round down 440 ELSE 450 Expected Round_up Minimum error is round up 460 END IF 470 END IF 480 SUBEND The following program can be called to wait for a source settled indication from the Signal Generator The program will wait a maximum of 1 second before assum ing the SOURCE SETTLED bit is not going to be set The status byte must be cleared with the CS program code before the frequency is set If the status byte is not cleared the SOURCE SETTLED bit may have been set by a previous command the bit is latched until the status byte is read or cleared 500 SUB Settled 510 Tcounter TIMEDATE in case no source settled 520 Stat SPOLL 719 f Serial poll 530 IF TIMEDATE T_counter gt 1 THEN Done Default of 1 second 540 IF NOT BIT Stat 3 THEN GOTO 520 Wait for set bit 550 Done 560 SUBEND Source is settled or 1 second has passed The following message numbers may be displayed when setting the sweep start frequency Each message is explained as it pertains to s
23. Adjust the VERNIER until the level meter indicates 6 dBm For the 50 dBm RANGE the VERNIER can adjust the output level from 60 to 47 dBm Remote The programming string for the setting the RF output level is composed of a program code numeric data and the units terminator The RF output level may be programmed directly or the RANGE and VERNIER may be programmed separately To program the Signal Generator to a level of 56 dBm the possible program strings are LE 56DM or RA 5ODBVE 6DM In addition the program code could be AP or PL instead of LE The alpha characters can be sent as upper or lower case or even mixed upper and lower case The Signal Generator RF output levelis valid once the SOURCE SETTLED bit of the status byteis set see Comments The units terminator could be DB or DM The Signal Generator accepts either terminator for all power related settings HD 8673C D Program Codes lt 29 Comments Programming Example Operation Detailed Operating Instructions Vernier Output Level conra Program Description Vernier Setting RF Output Level RF Output Level RF Output Level Preferred Program Code The VERNIER controls the automatic level control ALC circuit directly The ALC is capable of controlling the RF output level over a 10 to 13 dBm range Additional dynamic range is provided by a 90 dB step attenuator that is controlled by the RANGE setting In re
24. External ALC enables the Signal Generator to level the signal at a point other than the output of the Signal Generator The signal level must be detected using a signal splitter or a directional coupler and a detector to provide a DC signal that is proportional to power at the remote point The Signal Generator will adjust the signal level at the RF output connector to maintain a constant level at the point where the signal is detected External ALC also enables external devices such as amplifiers mixers and other specialized devices to be inserted into the RF signal path with control of the final output level by the Signal Generator In applications where the external signal path has frequency dependent losses and or gains the RF signal at the end of the signal path will no longer be a constant amplitude over the Signal Generator s frequency range For example if a cable is used that has a constant 0 5 dB GHz loss a level error of 5 dB would occur after a 10 GHz frequency change The signal at the RF output connector of the Signal Generator has not changed but an extra 5 dB of attenuation is introduced in the signal path when the output frequency is changed System leveling mode is available on system compatible Signal Generators only To determine if a specific Signal Generator is system compatible see paragraph 3 2 System Compatibility System leveling is used with other system compatible equip ment to provide the Signal Generator with t
25. Figure 3 7 Rear Panel Features Operation HP 86738C D OPERATOR S CHECKS 3 17 OPERATOR S CHECKS 3 18 Basic Functional Checks Description Equipment Procedure 3 16 The purpose of these checks is to give reasonable assurance that the instrument is operating properly Each check has been designed to be performed with a minimum of test equipment and in as short a time as possible Therefore although these checks are extremely valuable in identifying malfunctions they are not a substitute for the Performance Tests in Section IV which verify that the instrument is performing within its published specifications Each check is independent from the others and can be performed separately Simply press RCL 0 to preset the Signal Generator to a known state before beginning an individual check If a malfunction is suspected the entire procedure should be performed in the order given Make a note of all the checks that failed Refer to the Service Manual for the appropriate troubleshooting procedures to follow if the Signal Generator is to be repaired at the user s facility If the instrument is to be returned to Hewlett Packard for repair fill out a blue repair tag found at the end of this manual Include on the back of the tag a list of all checks that failed and attach the tag to the instrument This will give the repair technician a good description of the malfunction and help assure the best possible service and the
26. Generator to output its lock frequency Address the Generator to talk and 30 ENTER 719 V ENTER 719 V store its output in variable V Display the value of V 40 DISP V DISP V 50 END Operator s Check that the Signal Generators TLK annunciator is on The controller s display Response should read 3 E 9 series 200 300 or 3000000000 HP 85B This corresponds to the data output shown in the FREQUENCY MHz display Local Lockout and Clear Lockout Set Local Messages Note This check determines if the Signal Generator properly receives the Local Lockout message disabling the LOCAL key The check also determines if the Clear Lockout Set Local message is properly received and executed by the Signal Generator This check assumes that the Signal Generator is in the remote mode Description Series 200 300 HP 858 BASIC Send the Local Lockout message LOCAL LOCKOUT 7 LOCAL LOCKOUT 7 Operator s Check that the Signal Generator s RMT annunciator is on Press the Signal Generator s Response LOCAL key The RMT annunciator should remain on Send the Clear Lockout Set Local message Operator s Check that the Signal Generator s RMT annunciator is off but the TLK annunciator is Response still on Return the Signal Generator to remote REMOTE 719 REMOTE 719 mode if the remaining checks in this section are to be performed Operaior s Check that the Signal Generator s RMT and LSN annunciators are on Response 3 26 HD
27. If auto trigger mode is selected while digitizing the oscilloscope will trigger the sweep even without an external trigger sig nal and the waveform digitized will not be valid for this measurement 3 Set the oscilloscope s main sweep to 5 ms per division and delayed sweep to 4 1 ms per division The delayed sweep will be used once the approximate delay required is determined from the main sweep Set the Signal Generator to the following conditions Output Level occ sese 0 dBm ALC au Go dace Wee EA S OE eaten Or aeees Internal Modulation voe teoveenssamoaienseeeselias Off Sweep Mode e Manual Start Frequency 0 0 ceeeeees 3 000 000 MHz Stop Frequency 1 900 000 MHz Sled hat caren cut See seh eeu es 1 Step Dwell corser cei eicatotniead Meena eees 20 ms Auto Peak a hn pete sae wind oe eae ERRAN Off 4 29 Performance Tests HP 86738C D PERFORMANCE TESTS FREQUENCY SWITCHING TIME TEST contd Procedure 5 cont d 6 7 8 9 Set the local oscillator to 1 900 001 MHz with an output level of 8 dBm Using the FREQ INCREMENT keys set the Signal Generator to the stop frequency 1 900 000 MHz Set the oscilloscope s main sweep mode to AUTO Adjust the oscilloscope s chan nel 1 vertical sensitivity for a 2 division peak to peak display of the IF frequency Set the oscilloscope s main sweep mode to triggered or NORM This sweep mode will not trigger the digitizer un
28. Initial Setup Equipment These procedures check the Signal Generator s ability to process or send the HP IB mes sages described in Table 3 4 Only the Signal Generator a controller and an HP IB interface are needed to perform these checks These procedures do not check if all Signal Generator program codes are being properly interpreted and executed by the instrument However if the power up sequence includ ing the memory checks and the front panel operation is good the program codes in all likelihood will be correctly implemented The validity of these checks is based on the following assumptions a The Signal Generator performs properly when operated via the front panel keys that is in local mode This can be verified by the Basic Functional Checks b The bus controller properly executes HP IB operations c The bus controller s HP IB interface properly executes the HP IB operations If the Signal Generator appears to fail any of these HP IB checks the validity of the above assumptions should be confirmed before attempting to service the instrument The select code of the controller s HP IB interface is assumed to be 7 The address of the Signal Generator is assumed to be 19 its address as set at the factory This particular select code address combination that is 719 is not necessary for these checks to be valid However the program lines presented here have to be modified for any other combinati
29. NO ERROR 13 NUMBER OF STEPS ADJUSTED TO i GIVE STEP SIZE IN EVEN kHz Press Messages 01 09 are operator errors The entry is STEP to see result ignored and the previous values are retained B 14 STEP SIZE TOO SMALL FOR SPAN Press 01 FREQUENCY OUT OF RANGE STEP to see result maximum number of FREQ INCR OUT OF RANGE steps is 9999 MULTIPLIER ENTRY OUT OF RANGE 15 STEP SIZE gt SPAN Step size is set to span CANNOT STORE REGISTER 0 16 BAND CROSSING IN AUTO SWEEP STEP SIZE OUT OF RANGE g BYPASS AND SYSTEM LEVELING NOT Messages 20 24 are HP IB errors The entry 1s FUNCTIONAL BELOW 2 0 GHz aia o L a NUMBER OF STEPS OUT OF RANGE an INVALID HP IB CODE DWELL OUT OF RANGE 21 HP IB DATA WITHOUT VALID PREFIX MARKER NUMBER NOT 1 5 22 INVALID HP IB ADDRESS ENTRY Messages 10 16 are soft errors that result from 23 TALK TUNCHONNOT Sonny unusual combinations of sweep entries A message l T oe is displayed and all entered values are stored in 24 OUTPUT LEVEL OUT OF RANGE anticipation that further entries will resolve the Sane conflict Messages 30 99 are service related errors Refer to Section VIH in the manual SWEEP SPAN RESULTS IN START 90 AUTO PEAK FUNCTION FREQUENCY OUT OF RANGE Truncated 92 RECALL CHECKSUM ERROR Sop will well 95 LOSS OF DATA ON POWER UP SWEEP SPAN RESULTS IN STOP S T 97 ROM TEST FAILURE A2A10 FREQUENCY OUT OF RANGE Truncated E Babe sweep will result 98 RAM
30. Set the Signal Generator s AM switch to OFF Set the FM DEVIATION range to contd 1 MHz 6 Connect the test oscillator to the Signal Generator s FM IN connector 7 Set the test oscillator frequency to 100 kHz 8 Vary the test oscillator amplitude between 0 and 0 5 Vrms Verify that the voltmeter reading is less than the level recorded in step 4 Record the maximum level 1 0 GHz Vrms 9 Repeat step 8 for Signal Generator frequencies of 2 0 GHz 6 7 GHz and 12 4 GHz 2 0GHz ___ ss Vrms 6 7 GHz V Trn 12 4 GHz Vrms HP 8673D only 10 Tune the Signal Generator to 18 7 GHz Vary the test oscillator amplitude between 0 and 0 707 Vrms Verify that the voltmeter reading does not exceed the level recorded in step 4 Record the maximum level 18 7 GHz V TnS 4 90 HP 8678C D Hewlett Packard Company Table 4 4 Performance Test Record 1 of 13 Performance Tests Model HP 8678C D Tested by GS SCANT I Signal Generator Serial Number Date Results Para Test Peer No Min Actual Max 4 8 FREQUENCY RANGE AND RESOLUTION Baseband Test 50 000 MHz 50 000 eee 50 001 2 000 000 MHz 1 999 999 z 2 000 001 2 000 001 MHz 2 000 000 KR 2 000 002 2 001 112 MHz 2 001 111 See aes Ue we isha 2 002 223 MHz 2 002 222 _ 2 002 224 2 003 334 MHz 2 008 333 Serta i Oa 2 003 335 2 004 445 MHz 2 004 444 2 004 446 2 005 556 MHz 2 005 555 Fe eerste 2 005 557 2 006 667 MHz 2 006 666 eee eee 2 00
31. The alpha character P can be sent as upper or lower case HP 86738C D Program Codes Comments Operation Detailed Operating Instructions Pulse Modulation conta Program Code Description PO Pulse Off PI Pulse Off P2 Pulse Normal Mode P3 Pulse Complement Mode Overmodulation in pulse mode due to peak level accuracy degradation narrow pulse widths or an extremely low duty cycle too long between pulses are indicated by the ALC UNLEVELED annunciator The overmodulation condition can be read by the controller using the ALC UNLEVELED bit of the extended status byte Major pulse modulation specifications are not warranted unless an Auto Peak operation has been performed An Auto Peak operation is performed automatically whenever the frequency is changed by more than 20 MHz while Auto Peak is enabled or the output level is changed by more than 0 4 dB while pulse modulation is enabled Changes in load impedance can shift the center frequency of internal filters and require an Auto Peak operation to maintain optimum pulse performance This could occur if highly reactive loads are switched in and out in automatic test systems Large frequency changes cause changes in the self heating of internal Yittrium Iron Garnet YIG filters Most of the filter passband drift occurs in 15 to 20 seconds but complete settling can require up to 15 minutes Some experimentation may be required to determine when the Auto Peak operat
32. has entered the talk only mode 4 Designate the second Signal Generator as the Slave unit by setting the HP IB address to 40 When the HP IB address is set to 40 the LSN annunciator on the front panel will light 5 On both instruments set SWEEP START and SWEEP STOP frequencies to the desired Master sweep values 6 On both instruments set the number of sweep steps to the desired value For constant offsets both instruments must be set for the same number of steps 7 On the Slave unit select a frequency offset by resetting the Slave center frequency to the desired offset from the Master center frequency 8 Press and hold the SWEEP START frequency key on the Slave unit The frequency should be different from the Master unit start frequency by the desired offset The SWEEP STOP frequency should also be offset by the same amount 9 To operate Master Slave sweep in AUTO sweep mode press AUTO on the Master unit The Master unit will begin to sweep and the Slave unit will track it The Slave unit will enter Slave mode when sweep is selected on the Master unit When the Signal Generator is in Slave mode the MANUAL and SINGLE indicators will be illuminated 10 To operate Master Slavein MANU AL sweep mode Press MANUAL on the Master unit Use the TUNE knob on the Master unit to tune both Master and Slave units The Slave unit will enter Slave mode when sweep is selected on the Master unit When the Signal Generator is in Slave mode the
33. played as entered but the actual instrument output frequency will be the offset amount ABOVE the entered and displayed frequency MKR Key Enables previously selected marker fre quencies when used as a prefix to Data keys 1 through 5 For example pressing MKR and 1 enables Marker 1 When used as prefix to the Data and Units keys it sets marker frequencies For example press ing MKR 3 15 and GHz sets the frequency of Marker 3 to 15 GHz The first digit pressed after the MKR key is always the marker number Pressing the MKR key displays all currently enabled marker numbers within the set sweep range in the FRE QUENCY MHz display Pressing the MKR key anda Data key displays the present frequency of the requested marker SWEEP MODE B OFF Key Disables all sweep modes O AUTO Key Starts a repetitive sweep restarting at the end of each sweep Executes single sweep oniy if sweep range includes 2 3 5 6 16 HP 8673D only or 22 GHz in NORMAL mode see Additional Operating information paragraph 3 14 a MANUAL Key Enables the sweep circuitry It does not Start a sweep The TUNE knob if enabled or the FREQ INCREMENT lt and gt keys control the sweep as SINGLE Key Arms the single sweep and tunes the Signal Generator to the start frequency The sweep does not begin until the key is pressed again to trigger the sweep When pressed during a sweep the in progress sweep aborts and rearms the single sweep SWEE
34. register is recalled in local mode the remote VERNIER setting will be selected and local VERNIER control will be disabled The local VERNIER setting is stored when a register is stored in local mode Recalling this register in remote mode will use the stored local mode setting as the remote VERNIER setting There are two preset states that can be selected in remote mode or from the front panel The first preset state is selected by recalling register zero in local or remote mode or sending the program code IP in remote mode The register 0 preset conditions are given below 3 123 Operation HP 8673C D Detailed Operating Instructions Comments contd Error Messages 3 124 Recall and Store Registers conta RF OUTPUT to ON ALC mode to INT RANGE to 70 dB 0 dB for Options 001 and 005 AUTO PEAK to ON MTR scale to LVL AM FM and PULSE modulation to OFF FREQUENCY to 3000 000 MHz FREQ INCR to 1 000 MHz START to 2000 000 MHz STOP to 4000 000 MHz AF to 2000 000 MHz MK Rs disabled initialized to 3 6 9 12 and 15 GHz SWEEP MODE to OFF STEP to 100 steps 20 000 MHz DWELL to 20 ms TUNE knob to ON BYPASS NORMAL to NORMAL The alternate preset provides a different set of conditions more suitable for some applications The alternate preset conditions are given below RF OUTPUT to ON OFFSET frequency to 0 MULTIPLIER and ALC mode unchanged RANGE to 70 dB 0 dB for Options 001 and 005 AUTO PEAK to ON
35. respond to a parallel poll with the Status Bit mes sage However the Signal Generator cannot send Data messages and cannot respond to a serial poll with the Status Byte message The Signal Generator s Listen Only address can also be set from the front panel by keying in 4 0 then pressing the STO key and the LOCAL key Note that the FRONT PNL ENABLE switch on the internal HP IB address switch must be set to 1 to allow front panel entries Talk Only Mode If the internal address switches are set to a valid Talk address and the Talk Only switch is set to 1 the Signal Generator is placed in the Talk Only mode In this mode the instru ment is configured to send Data messages when ever the bus is in the data mode It can also send the Status Byte message in response to a serial poll HP 8678C D Addressing cont d The Signal Generator s Talk Only address can also be set from the front panel by keying in 5 0 then pressing the STO key and the LOCAL key Note that the FRONT PNL ENABLE switch on the internal HP IB address switch must be set to 1 to allow front panel entries 3 28 Turn on Default Conditions Several HP IB parameters are reset at turn on The parameters and their default conditions are listed below HP IB Local Mode Immediate Execution Mode Unaddressed Trigger Configuration cleared Request Mask cleared SRQ cleared amp amp 3 29 Displays The RMT annunciator is on whe
36. scope display The external trigger is the reference for determining switching speed The switching time is measured from the display s left graticule to the last point that the signal is more than 1 division from the middle horizontal graticule Refer to Figure 4 25 Record the level switching time NOTE With the oscilloscope in delayed sweep mode the left graticule of the display corresponds to the delay time This delay must be added to the time from the left graticule to the last time the signal is more than 1 division from the middle graticule to obtain the level switching time lt 25 ms 13 Repeat steps 5 through 12 for each of the start and stop levels listed below Instead of re entering the program modify lines 10 100 and 110 and then run the program as directed Modify line 10 and 110 of the program by setting L2 to the stop level i e L2 0 Modify line 100 of the program by setting Li to the start level i e L1 88 Record the switch time for each indicated level change 4 62 HP 86738C D PERFORMANCE TESTS OUTPUT LEVEL SWITCHING TIME TEST contd Procedure cont d 1 ms div Start Level Stop Level Measured dBm dBm Switching Time Performance Tests 4 63 Performance Tests HP 86738C D PERFORMANCE TESTS 4 18 PULSE ON OFF RATIO TEST Specification f Electrical Performance Conditions Characteristics Characteristics ON OFF Ratio gt 50 dB 50 250 MHz gt 80 dB 0 250 26 0 GHz Des
37. shortest repair time Test Oscillator HP 3335A Pulse Generator e 2c eee HP 8013B or HP 8116A Oscilloscope ssi e Soar ee o eal HP 1980B Attenuator 10 dB HP 8493C Option 006 Turn On Check 1 Setthe upper LINE switch to STBY and the lower LINE switch to OFF Remove all external cables from the front and rear panels of the Signal Generator including the power cables connecting the instrument to mains power Set the rear panel FREQ STANDARD INT EXT switch to INT Connect the short jumper A3W3 between A3J9 and A3J10 Connect the long jumper W60 between 100 MHz OUT and 100 MHz REF INPUT 7 e RB N After the power cables have been disconnected from the Signal Generator for at least 1 minute reconnect them to the Signal Generator Check the front panel of the instrument to verify that the STANDBY and OVEN COLD status annunciators are on 6 Leave the instrument s upper LINE switch set to STBY until the OVEN COLD status annunciator turns off This should occur in 15 minutes or less depending upon how long the Signal Generator was disconnected from mains power The OVEN COLD annunciator may flicker off and on temporarily just as the oven stabilization temperature is reached This is normal operation Once the OVEN COLD status annunciator is off set both LINE switches to ON HP 8678C D Operation OPERATOR S CHECKS Basic Functional Checks contd Procedure NOTES cont d If the MESSAGE key ind
38. the TUNE knob or the FREQ INCREMENT up or down key The bit is set once the entry is completed For example the bit is set after the units key is pressed when setting the frequency Since front panel entry is disabled when in remote mode this bit is not set for entries during remote mode When used in conjunction with the FRONT PANEL KEY PRESSED bit the controller can determine when a user begins entering a front panel value and when the entry is complete The FRONT ENTRY COMPLETE bit can also be used to detect when the FREQ INCREMENT up or down key is released The bit will continue to be set until the key is released The FRONT PANEL KEY PRESSED bit will only be set once for this condition CHANGE IN EXTENDED STATUS The status byte can be read using a serial poll but the extended status byte requires a program code to be sent to the Signal Generator and then the controller must read both the status byte and the extended status byte from the Signal Generator The CHANGE IN EXTENDED STATUS bit is used to indicate that the extended status byte has changed from its value the last time was read This enables the status byte to be monitored using a serial poll until there is a status change in the extended status byte Once a change has occurred the controller can read the extended status byte to check the instrument status For more information regarding the use of this status bit see the Comments section SOURCE SETTLED The Signal Generator
39. tions Auto Peak occurs every 20 MHz and for output level VERNIER changes of 0 4dB or more See the pulse modulation detailed operating instructions for more information regarding pulse modulation and Auto Peak To perform an Auto Peak operation 1 Press the AUTO PEAK key to disable Auto Peak operations If the key indicator is off this step is not required 2 Press the AUTO PEAK key again to enable Auto Peak operations The key indica tor should now be lighted The Auto Peak operation is performed immediately after the Auto Peak key is pressed if the key indicator was off Auto Peak should be enabled at all times to provide optimum RF output signals However for faster frequency switching times or digital sweeps Auto Peak may be disabled at the expense of slightly degrading the RF output signal There are three programming codes associated with the Auto Peak operation KO disables all Auto Peak operations Selecting pulse modulation will automatically re enable Auto Peak The disable programming code must follow the selection of pulse modulation mode if Auto Peak is to remain disabled K1 is used to enable Auto Peak operations if Auto Peak is disabled when the program code is received If Auto Peak is enabled when the program code is received an Auto Peak operation is performed and Auto Peak is left enabled In either case this program code will perform an Auto Peak operation Part of the Auto Peak operation algorithm involves a de
40. 000 5 130 000 5 320 000 5 510 000 5 700 000 5 900 000 6 100 000 6 600 000 Minimum Frequency MHz 2 089 999 2 280 000 2 471 111 2 662 222 2 853 333 3 044 444 3 235 555 3 426 666 3 617 777 3 808 888 3 999 998 4 179 999 4 369 999 4 559 999 4 749 999 4 939 999 5 129 999 5 319 999 5 509 999 5 699 999 5 899 999 6 099 999 5 999 999 Actual Frequency MHz Maximum Frequency MHz 2 090 001 2 280 002 2 471 113 2 662 224 2 853 335 3 044 446 3 235 557 3 426 668 3 617 779 3 808 890 4 000 000 4 180 001 4 370 001 4 560 001 4 750 001 4 940 001 5 130 001 5 320 001 5 510 001 5 700 001 5 900 001 6 100 001 6 600 001 HD 86738C D Performance Tests ABBREVIATED PERFORMANCE TESTS OUTPUT LEVEL AND FLATNESS TESTS Description This test checks output level maximum leveled power and output level flatness The output level test uses a power meter to verify that the specified maximum leveled output power can be generated over the full frequency range Level flatness measures the variation in output power level as the frequency is changed Equipment Power Meter CN LRA S HP 486A Power Senant inns RRR EERE Een ae es HP 8485A HP 8673C D SYNTHESIZED SIGNAL GENERATOR POWER METER POWER SENSOR Figure 4 2 Output Level and Flatness Test Setup Procedure Output Level Test a 2 3 10 Connect the equipment as shown in Figure 4 2 Zero and calibrate th
41. 020 3 dB Attenuator HP 8491A Option 003 10 dB Attenuator HP 8491A Option 010 HP 8673C D SYNTHESIZED SIGNAL GENERATOR LOCAL OSCILLATOR G 69009 g RF OUTPUT OSCILLOSCOPE EXT TRIGGER TRIGGER OUT ATTENUATOR VERTICAL INPUT 3 dB PREAMPLIFIER 10 dB POWER AMP ATTENUATOR ATTENUATOR Figure 4 30 Pulse Peak Level Accuracy Test Setup Procedure 1 Connect the equipment as shown in Figure 4 30 2 Set the Signal Generator to 1 93 GHz with an output amplitude of 10 dBm 3 Set the local oscillator to 2 0 GHz with an output amplitude of 8 dBm 4 Set the pulse generator for a 100 ns pulse width at a 1 MHz pulse rate 4 73 Performance Tests HP 8673C D PERFORMANCE TESTS PULSE PEAK LEVEL ACCURACY TEST cont d Procedure contd 5 Set the Signal Generator to PULSE NORM Adjust the oscilloscope vertical posi 10 tion and sensitivity controls so that the pulse base line is one division from the bottom graticule line and approximately 5 divisions high in peak amplitude Adjust the RF pulse width with the pulse generator to obtain a 100 ns RF pulse width as displayed on the oscilloscope Switch the Signal Generator to CW mode Adjust the oscilloscope s vertical sensitivity controls to place the peak of the CW signal on the fifth graticule above the pulse base line refer to Figure 4 31 The peak of the CW signal is now the CW peak reference leve
42. 05 2 0 GHz 4 95 Performance Tests Para Ne 4 16 4 96 ABSOLUTE LEVEL ACCURACY cont d High Level Accuracy contd 5 dBm 10 dB range 0 05 2 0 GHz 5 dBm 10 dB range 2 0 6 6 GHz 6 6 12 3 GHz 12 3 16 0 GHz 2 dBm 10 dB range 0 05 2 0 GHz 2 0 6 6 GHz 6 6 12 38 GHz 12 3 18 6 GHz HP 8673D only 18 6 26 0 GHz 5 0 dBm 0 dB range 0 05 2 0 GHz 2 0 6 6 GHz 6 6 12 3 GHz 12 3 18 6 GHz HP 8678D only 18 6 26 0 GHz 10 dBm 0 dB range 0 05 2 0 GHz 2 0 6 6 GHz 6 6 12 3 GHz 12 8 18 6 GHz HP 8673D only 18 6 26 0 GHz 10 dBm 10 dB range 0 05 2 0 GHz 2 0 6 6 GHz 6 6 12 3 GHz 12 3 18 6 GHz HP 8673D only 18 6 26 0 GHz 20 dBm 20 dB range 0 05 2 0 GHz 2 0 6 6 GHz 6 6 12 3 GHz 12 3 18 6 GHz HP 8673D only 18 6 26 0 GHz Table 4 4 Performance Test Record 6 of 13 2 00 dB 2 00 dB 2 00 dB 2 50 dB 2 00 dB 2 00 dB 2 25 dB 2 50 dB 3 00 dB 1 75 dB 1 75 dB 2 00 dB 2 25 dB 2 75 dB 1 75 dB 1 75 dB 2 00 dB 2 25 dB 2 75 dB 2 25 dB 2 25 dB 2 50 dB 2 85 dB Results Actua HP 8673C D 2 00 dB 2 00 dB 2 00 dB 2 50 dB 2 00 dB 2 00 dB 2 25 dB 2 50 dB 3 00 dB 1 75 dB 1 75 dB 2 00 dB 2 25 dB 2 75 dB 1 75 dB 1 75 dB 2 00 dB 2 25 dB 2 75 dB 2 25 dB 2 25 d
43. 05 dBm 95 25 dBm PERFORMANCE TESTS Results Actual Max 27 25 dBm 37 15 dBm 47 05 dBm 56 95 dBm 66 85 dBm 76 75 dBm 86 65 dBm 27 25 dBm 37 15 dBm 47 05 dBm 56 95 dBm 66 85 dBm 76 75 dBm 86 65 dBm 27 00 dBm 36 90 dBm 46 80 dBm 56 70 dBm 66 60 dBm 76 50 dBm 86 40 dBm 26 55 dBm 36 35 dBm 46 15 dBm 55 95 dBm 65 75 dBm 75 55 dBm 85 35 dBm 25 95 dBm 35 75 dBm 45 55 dBm 55 35 dBm 65 15 dBm 74 95 dBm 84 75 dBm HP 8673C D HP 8673C D Performance Tests PERFORMANCE TESTS 4 17 OUTPUT LEVEL SWITCHING TIME TEST Specification Description Equipment Electrical Performance Characteristics Characteristics L 2 Conditions SWITCHING TIME Output level to be within 1 dB of final lt 25 ms output level This test measures the output level switching speed of the Signal Generator The Signal Generator output is detected using a crystal detector The detected amplitude is displayed on the oscilloscope Level switching speed is measured using a digitizing oscilloscope The oscilloscope is set to trigger the digitizing process at the beginning of a small frequency change which produces a trigger signal at the Signal Generator s Blanking Marker rear panel output As the unit under test is switched the RF output signal will be blanked and then rise and settle at a fixed ampli
44. 1 kHz offset gt 1 kHz offset lt 800 Hz offset 300 Hz 1 kHz offset gt 1 kHz offset 2 0 6 6 GHz 6 6 12 3 GHz 12 3 18 6 GHz 18 6 26 0 GHz Actual HP 8673C D Max 60 dBe 60 dBc 60 dBc 60 dBc 60 dBe 60 dBc 60 dBc 60 dBe 60 dBc 60 dBe 60 dBe 60 dBe lt 60 dBe lt 70 dBe lt 60 dBe lt 70 dBe 50 dBc 60 dBc 65 dBe 50 dBe 60 dBc 65 dBe 44 dBc 54 dBe 59 dBc 40 dBc 50 dBc 55 dBe 38 dBc 48 dBe 53 dBc HP 86738C D Performance Tests Table 4 4 Performance Test Record 5 of 13 4 15 QUTPUT LEVEL AND FLATNESS Output Level Frequency and power at minimum power point 0 05 2 0 GHz Frequency Minimum power 11dBm 2 0 16 0 GHz NORMAL mode Frequency Minimum power 2 0 16 0 GHz BYPASS mode Frequency Minimum power 16 0 18 0 GHz NORMAL mode Frequency Minimum power 2 0 dBm 16 0 18 0 GHz BYPASS mode Frequency Minimum power 5 0 dBm HP 8673D only 16 0 26 0 GHz NORMAL mode Frequency Minimum power 6 0 dBm 16 0 26 0 GHz BYPASS mode Frequency Minimum power 7 0 dBm Level Flatness total variation 0 05 2 0 GHz 0 50 dB 2 0 6 6 GHz 0 75 dB 6 6 12 3 GHz 1 00 dB 12 3 18 6 GHz 1 25 dB HP 8673D only 18 6 26 0 GHz 1 75 dB ABSOLUTE LEVEL ACCURACY High Level Accuracy 11 dBm 10 dB range 0
45. 10 dBm Rise 40 ns Fail 40 ns Overshoot and Ringing 30 6700 002 MHz at 8 dBm Rise 40 ns Fall 40 ns Overshoot and Ringing 30 6700 002 MHz at 0 dBm Rise 40 ns Fall 40 ns Overshoot and Ringing 30 i 6700 002 MHz at 10 dBm Rise 40 ns Fall 40 ns Overshoot and Ringing 30 12290 002 MHz at 8 dBm Rise 40 ns Fall 40 ns Overshoot and Ringing 25 12290 002 MHz at 0 dBm Rise eee SPN 40 ns Fall ne TT 40 ns Overshoot and Ringing a 25 12290 002 MHz at 10 dBm Rise EEA 40 ns Fall n 40 ns Overshoot and Ringing eae 25 12300 008 MHz at 5dBm Rise Cae Sere Pars 40 ns Fall paver eects 40 ns Overshoot and Ringing sale ie 25 12300 003 MHz at 0 dBm Rise here ae eerie 40 ns Fall Rec o o 40 ns Overshoot and Ringing e 25 4 99 Performance Tests HP 8673C D Table 4 4 Performance Test Record 10 of 13 Results Test No 4 19 PULSE RISE FALL TIMES AND OVERSHOOT cont d 12300 008 MHz at 10 dBm Rise Fall Overshoot and Ringing HP 8673C only 17990 008 MHz at 2 dBm Rise Fall Overshoot and Ringing 17990 003 MHz at 0 dBm Rise Fall Overshoot and Ringing 17990 003 MHz at 10 dBm Rise Fall Overshoot and Ringmg 18590 004 MHz at 2 dBm Rise Fall Overshoot and Ringing 18590 004 MHz at 0 dBm Rise Fall Overshoot and Ringing 18590 004 MHz at 10 dBm Rise Fall Overshoot and Ringing HP 8673D only 17990 003 MHz at 5 dBm Rise Fall Overshoot and Ringing 17990 003 MHz at 0 dBm Rise
46. 10 milli watts 10 dBm The RF output signal would be reduced for a detected level of 10 mil liwatts which would reduce the amplitude of the fundamental and introduce an error in the leveled RF output Example 1 External ALC over the range of 0 to 10 dBm is required The RF signal path exhibits an insertion loss of 4 dB that varies 2 dB over the frequency range To control the output level over a 0 to 10 dBm range an amplifier capable of 16 dBm 10 dBm 4dB 2 dB is required The range selected for this application depends mainly on the gain of the amplifier If we assume a gain of 10 dB the optimum Signal Generator range is 0 dB The overall signal path gain varies from 12 to 16 dBm To reduce the Signal Generator output level to 10 dBm would require 10 dB of attenuation The range is set 10 dB above this requirement or 0 dB Example 2 The IF output of a mixer is to be leveled at 20 dBm The conversion loss of the mixer is 10 dB and varies 3 dB over the frequency range Using the Signal Generator as the RF source for the mixer the diode detector is connected to the IF port of the mixer using a 10 dB directional coupler This will place the power at the diode at 30 dBm which is within the square law region of the detector The attenuation of the signal path is 10 dB and varies 3 dB For an IF level of 20 dBm the RF port must be at a level of approximately 10 dBm The range selected for the Signal Generator would
47. 100 000 H i j j Stop Fregueny MHz 1 900 000 1 900 000 1 900 000 2 090 000 2 100 000 2 100 000 2 200 000 3 000 000 6 490 000 6 500 000 6 590 000 6 610 000 12 400 000 2 100 000 2 100 000 19 500 000 26 000 000 26 000 000 LO Frequency MHz 1 900 001 1 900 001 1 900 001 2 090 001 2 100 001 2 100 001 2 200 001 3 000 001 6 489 999 6 499 999 6 590 001 6 609 998 12 399 998 2 100 001 2 100 001 19 499 999 25 999 996 25 999 996 Measured Switching Time lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms lt 50 ms Set the oscilloscope to main sweep with auto sweep mode This allows viewing the IF signal without using the external trigger signal Using the FREQ INCREMENT keys set the Signal Generator to 6 6 GHz and set the output level to 3 dBm Adjust the vertical sensitivity and position of the oscilloscope display main sweep until a change in output level from 3 dBm to 3 dBm indicates an IF signal amplitude change of exactly 4 divisions peak to peak This calibrates the oscillo scope display to 3dB about 0 dBm The smaller signal represents 3 dBm and the larger signal represents 3 dBm Set the top of the displayed signal to a convenient reference near the center of the display Note the 3 dBm and 3 dBm levels for reference The measurement will be determined by the time required before the
48. 29 Pulse Definitions Pulse Rise Time The time required for a pulse to increase from 10 to 90 of peak amplitude Tp Pulse Fall Time The time required for a pulse to decrease from 90 to 10 of peak amplitude Tp Overshoot and Ringing The ratio of pulse overshoot V to peak amplitude Vp V V 8 Tune the Signal Generator to 500 MHz Measure the pulse rise time fall time overshoot and ringing Record the results Rise Time lt 20 ns Fall Time n lt 20 ns Overshoot and Ringing __ lt 25 9 Replace the mixer in the circuit with the RHG DMS1 26 mixer 10 Repeat step 7 for the frequencies listed in the table below FREQUENCY OUTPUT LEVEL Overshoot MHz RANGE VERNIER apd Ringing 1000 00 10dB 1 dBm 1500 00 10dB 1 dBm 11 Tune the Signal Generator to 2000 MHz The local oscillator should track the Signal Generator frequency with a 70 MHz offset 4 69 Performance Tests HP 8673C D PERFORMANCE TESTS PULSE RISE FALL TIME AND OVERSHOOT TEST cont d Procedure 12 cont d 13 14 4 70 Measure the pulse rise time fall time overshoot and ringing Record the results Rise Time lt 40 ns Fall Time iC lt 40 ns Overshoot and Ringing lt 25 Tune the Signal Generator to 6600 MHz Measure the pulse rise time fall time over shoot and ringing Record the results Rise Time lt 40 ns Fall Time n lt 40 na Overshoot and Ringing lt 25 S
49. 460 END IF 470 END IF 480 SUBEND The following program can be called to wait for a source settled indication from the Signal Generator The program will wait a maximum of 1 second before assuming the SOURCE SETTLED bit is not going to be set The status byte must be cleared with the CS program code before the frequency is set If the status byte is not cleared the SOURCE SETTLED bit may have been set by a previous command the bit is latched until the status byte is read or cleared 500 SUB Settled 510 T counter TIMEDATE In case no source settled 520 Stat SPOLL 719 Serial poll 530 IF TIMEDATE T_counter gt 1 THEN Done Default of 1 second 540 IF NOT BIT Stat 3 THEN GOTO 520 Wait for set bit 550 Done 560 SUBEND Source is settled or 1 second has passed The following message numbers may be displayed when setting the CW frequency Each message is explained as it pertains to setting CW frequency For a more complete description of the messages see the MESSAGES detailed operating instructions 01 Entered frequency is not within the range of the Signal Generator 03 Invalid multiplier entry for system compatible instruments Error 03 is defined as BYPASS mode not functional below 2 GHz for non system compatible instru ments See paragraph 3 2 System Compatibility for more information about system compatibility 06 TheBYPASS mode and SYSTEM leveling cannot be selected for frequencies below 2 GHz This error is o
50. 60 P_code NM 70 CASE ELSE 80 DISP WARNING Invalid mode specified 90 Err 1 100 SUBEXIT 110 END SELECT 120 130 OUTPUT 719 USING 2A P_code 140 SUBEND The following message numbers may be displayed when setting BYPASS mode Each message is displayed as it relates to the setting of BYPASS mode For a more complete description of the messages see the MESSAGES detailed operating instructions 03 Error 03 is defined as BYPASS mode not functional below 2 GHz for non system compatible instruments See paragraph 3 2 System Compatibility for more information about system compatibility 06 The BYPASS mode and SYSTEM leveling cannot be selected for frequencies below 2 GHz This error is only defined for system compatible instruments See paragraph 3 2 System Compatibility for more information HD 8673C D Description Local Procedure Remote Procedure Operation Detailed Operating Instructions Offset Frequency For applications that require a constant frequency offset to be used when setting the Signal Generator frequency a frequency offset can be entered For example using the Signal Generator as a local oscillator with a frequency offset equal to the IF frequency allow both the RF source and the local oscillator to be set to the same frequency Because of the offset frequency on the local oscillator the actual frequency will be lower or higher than the programmed frequency which will maintain the corr
51. 70 OUTPUT 719 USING 2A MG Check for message from 8673 80 ENTER 719 USING 2A Message 90 SELECT VAL Message 400 CASE 1 Frequency was out of range 110 Err 1 120 DISP WARNING Attempt to set sweep start frequency out of range 130 CASE 10 140 Err 10 150 DISP WARNING Sweep start and stop frequency are equal 160 CASE 90 Auto Peak Error 170 Err 90 180 DISP WARNING Auto Peak error Service may be required 190 CASE ELSE 200 Err 0 Other errors not applicable 210 END SELECT 220 230 OUTPUT 719 USING 4A FAOA Requests current start freq 240 ENTER 719 USING K Set_freq Frequency in Hz 250 Set_freq INT Set_freg 1000 1000 Convert to MHz 260 270 IF ABS Set_freq Frequency gt 001 AND Err 0 THEN 280 DISP WARNING Requested frequency rounded to Set_freq 290 END IF l 295 SUBEND End of subroutine 3 134 HP 8673C D Programming Example cont d Error Messages Operation Detailed Operating Instructions Start Frequency Sweep conta To prevent roundoff errors from occurring the following subprogram may be used to adjust a frequency so that it is always within 1 or 2 kHz of the desired frequency Frequencies below 18 6 GHz will be within 1 kHz of the desired frequency and frequen cies between 18 6 and 26 GHz will be within 2 kHz of the desired frequency 300 SUB Round_off Err Expected Expected frequency in MHz 310 Err 0 Initialize Err 320 Band 5
52. 700 000 MHz 5 900 000 MHz 6 100 000 MHz 6 600 000 MHz QUTPUT LEVEL AND FLATNESS Output Level 4 20 Frequency and Power at Minimum Power Point 0 05 2 0 GHz Frequency Minimum Power 2 0 16 0 GHz NORMAL mode Frequency Minimum Power 2 0 16 0 GHz BYPASS mode Frequency Minimum Power 16 0 18 0 GHz NORMAL mode Frequency Minimum Power 16 0 18 0 GHz BYPASS mode Frequency Minimum Power 50 000 2 089 999 2 280 000 2 471 111 2 662 222 2 853 333 2 044 444 3 235 555 3 426 666 3 617 777 3 808 888 3 999 998 4 179 999 4 369 999 4 559 999 4 749 999 4 939 999 5 129 999 5 319 999 5 509 999 5 699 999 5 899 999 6 099 999 5 999 999 2 0 dBm 5 0 dBm 50 001 2 090 001 2 280 002 2 471 113 2 662 224 2 853 335 3 044 446 3 235 557 3 426 668 3 617 776 3 808 890 4 000 000 4 180 001 4 370 001 4 560 001 4 750 001 4 940 001 5 130 001 5 320 001 5 510 001 5 700 001 5 900 001 6 100 001 6 600 001 HP 8673C D Performance Tests Table 4 1 Abbreviated Performance Test Record 2 of 3 Test OUTPUT LEVEL AND FLATNESS contd HP 8673D only 16 0 26 0 GHz NORMAL mode Frequency Minimum Power 16 0 26 0 GHz BYPASS mode Frequency Minimum Power Level Flatness total variation 0 05 2 0 GHz 0 50 dB 0 05 6 6 GHz 0 75 dB 0 05 12 3 GHz 1 00 dB 0 05 18 6 GHz 1 25 dB HP 8678D only 0 05 26 0 GHz 1 75 dB LEVEL ACCURACY High Level Accur
53. 719 Get the status byte 230 IF NOT BIT V 3 THEN GOTO 220 Wait for source to settle 240 3 161 Operation Detailed Operating Instructions Programming Example contd Error Messages 3 162 HP 86738C D Vernier Output Level conra 250 IF Expected gt 0 THEN Check for unleveied 260 OUTPUT 719 USING 2A 0S Get extended status byte 270 ENTER 719 USING B B V Extended 280 IF BIT Extenced 6 THEN 290 Err 1 300 DISP WARNING The Signal Generator RF output is not leveled 310 END IF 320 END IF 330 340 SUBEND The following message may be displayed when setting the RF output level Each message is displayed as it pertains to setting the RF output level For a more complete description of the messages see the MESSAGES detailed operating instructions 24 The programmed RF output level is not within the range of the Signal Generator HP 8673C D Performance Tests SECTION IV PERFORMANCE TESTS 4 1 INTRODUCTION The procedures in this section test the instrument s electrical performance using the specifications of Table 1 1 as the performance standards These tests are suitable for incoming inspection trouble shooting and preventive maintenance All tests can be performed without accessing the interior of the instrument A simpler operational test is in cluded in Section III under Operator s Checks NOTE To consider the performance tests valid the following conditio
54. 719 USING K Set_freq Frequency in Hz 250 Set_freg INT Set_freg 1000 1000 Convert to MHz 260 270 iF ABS Set_freq Frequency gt 001 AND Err 0 THEN 280 DISP WARNING Requested frequency rounded to Set_freq 290 END IF 295 SUBEND End of subroutine 3 153 Operation HP 8673C D Detailed Operating Instructions Programming Example contd Error Messages 3 154 Stop Frequency Sweep conra To prevent roundoff errors from occurring the following subprogram may be used to adjust a frequency so that it is always within 1 or 2 kHz of the desired frequency Frequencies below 18 6 GHz will be within 1 kHz of the desired frequency and frequen cies between 18 6 and 26 GHz will be within 2 kHz of the desired frequency 300 SUB Round_off Err Expected 1 Expected frequency in MHz 310 Err 0 l Initialize Err 320 Band 5 330 IF Expected lt 26500 001 THEN Band 4 340 IF Expected lt 18600 007 THEN Band 3 300 IF Expected lt 12300 001 THEN Band 2 360 IF Expected lt 6600 001 THEN Band 1 370 380 Baseband INT Expected 1000 Band 1000 Rounded fundamental 390 Round_down Baseband Band 400 IF Round_down lt gt Expected THEN Requires rounding 410 Round_up Baseband 001 Band 420 IF ABS Round_down Expected lt ABS Round_up Expected THEN 430 Expected Round_down Minimum error is round down 440 ELSE 450 Expected Round_up Minimum error is round up 460 END IF 470 END IF 480 SUBEND The following p
55. 75 AM for the 30 and 100 ranges respectively The spectrum analyzer will display a modulated signal at each of the active marker frequencies to provide calibrated frequency markers on the display The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program is used to set the marker specified by Marker to the frequency specified by the variable Expected The marker must be between 1 and 5 and the marker frequency can be any valid Signal Generator frequency 10 SUB Marker_set Err Marker Expected 20 IF Marker lt 1 or Marker gt 5 then 30 Err 1 40 DISP ERROR Marker number not between 1 and 5 50 SUBEXIT 60 END IF 70 80 OUTPUT 719 USING 2A MG Clear any old messages 90 ENTER 719 USING 2A Message 100 110 OUTPUT 719 USING 2A 5D DDD 2A M amp VALS Marker Expected MZ 120 130 OUTPUT 719 USING 2A MG Check for errors 140 ENTER 719 USING 2A Message 150 SELECT VAL Message 160 CASE 1 170 Err 1 180 DISP ERROR Marker frequency is out of range 190 CASE ELSE 200 Err 0 210 END SELECT 220 230 SUBEND The following messages may be displayed when setting the sweep markers Each message is explained as it pertains to setting sweep markers For a more complete description of the messages see the MESSAGES detailed operating instructions 01 The entered frequency is not within the range of the Signal Generator 09 The
56. 86738C D Detailed Operating Instructions Start Frequency Sweep conra Comments cont d Frequency Switch Point Description 2 GHz The microwave signal path is switched for downconversion when switching from above 2 GHz to below 2 GHz 2 GHz A low pass filter is switched in to reduce harmonics 2 0 3 5 GHz 3 5 GHz A low pass filter is switched in at this frequency to reduce harmonics 3 5 6 0 GHz 6 0 GHz A tracking bandpass filter is switched in from 6 to 22 GHz 18 6 for the HP 8673C to reduce harmonics and subharmonics above 6 6 GHz 16 0 GHz An amplifier is switched in to increase output power above 16 GHz HP 8673D only 22 0 GHz A high pass filter is switched in to reduce subharmonics HP 8673D only Programming The following programs are written in BASIC for HP 9000 Series 200 or 300 controllers Example The program below is used to set the Signal Generator to the sweep start frequency specified by the variable called Expected The desired value must bein MHz and should be within the frequency range of the Signal Generator 10 SUB Sweep_start_set Err Expected Expected frequency in MHz 20 OUTPUT 719 USING 2A MG Read message from 8673 30 ENTER 719 USING 2A Message to clear any old messages 40 Frequency iNT Expected 1000 1000 Round off to nearest kHz 50 OUTPUT 719 USING 4A 5D DDD 2A CSFA Frequency MZ T Update status 60 CALL Seitled Wait for source to settle
57. Connect the system feedback signal from the amplifier to the external ALC input connector on the Signal Generator front panel 3 Press the shift key and then the SYSTEM key shifted DIODE With the Signal Generator range set to 0 dB and above the output level of the amplifier can be directly controlled using the RANGE and VERNIER Remote 1 Perform the above steps 1 to 3 to connect the system 2 The controller can now directly set and read the output level of the RF amplifier by setting the Signal Generator output level to the desired level 3 157 Operation HP 8673C D Detailed Operating Instructions Program Codes Comments Application Example Error Messages 3 158 System Automatic Level Control conrg Program Code Function External System Leveling Mode Using external system leveling mode has the advantages of no calibration required built in temperature compensation direct control of the leveled RF signal and an extra range for high power applications The dynamic range available is dependent only on the signal path gain and losses Amplitude modulation up to 90 depth at rates as high as 80 kHz is typically available using system leveling mode The external ALC circuitry is used to adjust the Signal Generator s output level until the detected voltage at the external ALC inputis correct If high harmonics or spurious signals are present in the signal that is being detected they will affec
58. D Frequency Standard Selection cont d normally connects the FREQ STANDARD INT connector A3J9 to the FREQ STANDARD EXT connector A3J10 The FREQ STANDARD EXT connector can accept a reference signal to be used instead of the Signal Generator s internal fre quency standard The internal frequency standard is a 10 MHz sig nal at 7 dBm nominal with an aging rate of lt 5 x 107 0 day after warmup typically 24 hours When the FREQ STANDARD INT EXT switch is in the INT position and the jumper is connected between A3J9 and A3J10 the internal referenceis enabled When the FREQ STANDARD INT EXT switch is in the EXT position and the jumper is discon nected from the FREQ STANDARD EXT connec tor a frequency standard of 5 or 10 MHz at 0 dBm nominal can be connected NOTE The EXT REF status annunciator on the front panel will light when an external reference is being used Also the UN LOCKED status annunciator may light if the external reference is not of suffi cient accuracy in frequency or has an _ insufficient power level The external reference must be within 200 Hz of 10 MHz or 100 Hz of 6 MHz for reliable locking to occur If the external reference level is not within the specified limits 0 1 to 1 Vrms into 50 ohms its level may be sufficient to turn off the h UN LOCKED status annunciator giving a false indication of normal operation In fact the phase noise of the Signal Gen erator may be degraded
59. Frequency Sweep conta The following message numbers may be displayed when setting the sweep center frequency Each message is explained as it pertains to setting sweep center frequency For a more complete deseription of the messages see the MESSAGES detailed oper ating instruction 01 Entered frequency is not within the range of the Signal Generator 03 Invalid multiplier entry for system compatible instruments Error 03 is defined as BYPASS mode not functional below 2 GHz for non system compatible instru ments See paragraph 38 2 System Compatibility for more information about system compatibility 06 TheBYPASS mode and SYSTEM leveling cannot be selected for frequencies below 2 GHz This error is only defined for system compatible instruments See para graph 3 2 System Compatibility for more information 3 59 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure Remote Procedure 3 60 Delia Frequency Sweep The sweep delta frequency determines the sweep span about the center frequency The sweep frequency limits are determined by setting either the start and stop frequency or the center frequency and frequency span Setting start and stop frequency will begin the sweep at the start frequency and end at the stop frequency Setting the center frequency and sweep delta frequency will start the sweep at one half the sweep delta frequency below the center frequency and end th
60. HP 8673C D Detailed Operating Instructions Comments cont d 3 80 Frequency Increment and Tuning conta If the status byte is to be used to monitor settling the program string that changes the frequency should start with the program code CS This will clear any previous setting of the SOURCE SETTLED bit to avoid an incorrect indication For frequency changes greater than 50 MHz an Auto Peak operation is performed by the Signal Generator The Auto Peak operation optimizes the Signal Generator per formance at the set frequency The Auto Peak operation produces small changes in the RF output level as the peaking is performed In some cases the Auto Peak operation may require longer than the frequency switching time specification For applications requiring fastest switching speed Auto Peak may be disabled However with Auto Peak disabled modulation performance and maximumm output power may be degraded The SOURCE SETTLED bit of the status byte is set when the Auto Peak operation is completed However when sending several program codes in the same data string the SOURCE SETTLED bit may be set by one of the other program codes For maximum assurance that the Auto Peak is finished an Auto Peak should be performed just before the RF output is used for a measurement Once the SOURCE SETTLED bit is set after sending the program code K1 Auto Peak On the RF output is settled and the Auto Peak operation is finished The multiplied
61. Indicated level should not vary more than 1 dB from the level referenced with pulse off CW mode While in PULSE NORM mode slowly reduce the pulse width from 150 ns to 50 ns The UNLEVELED annunciator should come on as 100 ns pulse width is approached It should remain on down to at least 50 ns The output level indicated on Signal Generator meter may also vary gt 1 dB as the UNLEVELED annunciator comes on This is normal instrument operation indicating a pulse unleveled condition Set FREQUENCY to 1 0 GHz Repeat steps 49 50 Press PULSE OFF and disconnect the oscilloscope and test oscillator from the Signal Generator Memory Check 54 Oo Set FREQUENCY to 15 GHz and Output Level RANGE to 20 dB Turn the Signal Generator s upper LINE switch to STBY wait 30 seconds then turn the LINE switch to ON Verify that the FREQUENCY MHz display shows 15000 000 MHz and the RANGE dB display shows 20 dB Message Check 56 57 58 Press RCL 0 to preset the Signal Generator to a known state Enter a FREQUENCY of 30 GHz and verify that the FREQUENCY DISPLAY remains at 3000 MHz and the MESSAGE key indicator turns on Press and hold the MESSAGE key The FREQUENCY MHz display should show message code 01 frequency out of range Release the MESSAGE key Verify that the key indicator turns off 3 23 Operation HP 86738C D OPERATOR S CHECKS 3 19 HP IB Functional Checks TSR Description
62. LSN annunciator Response is on Send the Remote message to the REMOTE 719 REMOTE 719 Signal Generator Operator s Check that both the Signal Generator s RMT and LSN annunciators are on Press the Response LOCAL key on the Signal Generator Check that the Signal Generator s RMT annuncia tor is now off but that its LSN annunciator remains on Receiving the Data Message Note This check determines if the Signal Generator properly receives Data messages Description Series 200 200 HP 858 BASIC Send the first part of the Remote REMOTE 7 message enabling the Signal Genera tor to remote Address the Signal Generator to OUTPUT 719 listen completing the Remote FRI5GZ OUTPUT 719 FR1I5GZ message then send a Data message Operator s The Signal Generator should be set to 15 GHz Response Sending the Data Message Note This check determines if the Signal Generator properly issues Data messages when addressed to talk Before beginning this check turn the Signal Generator s LINE switch to STBY then to ON Then key in RCL 0 to preset the instrument If a series 200 300 controller is used a short program is required to perform the check 3 25 Operation HP 8673C D OPERATOR S CHECKS HP IB Functional Checks contd Description Series 200 300 HP 858 BASIC Send the Remote message 10 REMOTE 719 REMOTE 719 Send a Data message causing 20 OUTPUT 719 OK OUTPUT 719 OK
63. MANUAL and SINGLE indicators will be illuminated 3 97 Operation HP 8673C D Detailed Operating Instructions Local Procedure contd Remote Procedure Example Comments 3 98 Master Slave Sweep conta 11 To operate Master Slavein SINGLE mode Press SINGLE on the Master unit once to arm the sweep Press it a second time to execute a single sweep If SINGLE is pressed during the sweep the in progress sweep stops and is re armed The Slave unit will enter Slave mode when sweep is selected on the Master unit When the Signal Generator is in Slave mode the MANUAL and SINGLE indicators be illuminated Master Slave sweep mode cannot be remotely programmed because the Master unit is acting as a limited HP IB controller To operate Master Slave sweep with an offset of 50 MHz 1 Interconnect the two Signal Generators using an HP IB cable 2 Press RCL 0 on both Signal Generators 3 Designate one Signal Generator as the master unit by setting the HP IB address to 50 When the HP IB address is set to 50 the TLK annunciator on the front panel will light 4 Designate the second Signal Generator as the Slave unit by setting the HP IB address to 40 When the HP IB address is set to 40 the LSN annunciator on the front panel will light 5 On both instruments set SWEEP START to 6000 MHz and SWEEP STOP to 12000 MHz 6 On both instruments set the number of sweep steps to 100 This corresponds to a sweep step siz
64. MTR scale to LVL AM FM and PULSE modulation to OFF FREQUENCY to 14 000 000 MHz X Multiplier FREQ INCR to 1 000 MHz X Multiplier START to 13 000 000 MHz X Multiplier STOP to 15 000 000 MHz X Multiplier AF to 2000 000 MHz X Multiplier MKRs disabled initialized to 3 6 9 12 and 15 GHz X Multiplier SWEEP MODE to OFF STEP to 100 steps 20 000 MHz X Multiplier DWELL to 20 ms TUNE knob to ON BYPASS NORMAL to NORMAL The following errors apply to storing or recalling instrument state registers 04 Cannot store a state in register 0 This register is reserved for instrument preset conditions 92 The data stored in the register being recalled has been corrupted The instrument will be reset HP 86738C D Description Local Procedure Remote Procedure Example Program Codes Comments Operation Detailed Operating Instructions RF Output On Off The RF output of the Signal Generator can be disabled with the RF ON OFF key on the front panel The RF output can be disabled when the minimum power level setting is not low enough to prevent interference as when zeroing a power meter using a high sensitivity power sensor With the RF output disabled the ALC UNLEVELED and UNLOCKED annunciators will turn on to indicate that the microwave signal source is disabled In addition if frequency modulation is enabled the FM OVERMOD annunciator will also light To turn off the RF output 1 Press the RF ON OFF key Th
65. Performance Tests HP 86738C D PERFORMANCE TESTS PULSE RISE FALL TIME AND OVERSHOOT TEST cont d Procedure cont d 4 68 6 10 Fi 0 20 FO 0 30 OUTPUT 719 FROA T O 40 ENTER 719 F2 45 OUTPUT 719 CS 50 LOCAL 719 Read current UUT frequency Convert reading to MHz 55 F2 F2 1000000 60 IF F2 lt gt F1 THEN Fi F2 eo 70 F3 F1 70 Calculate 70 MHz offset frequency Calculate 15 MHz offset frequency 80 IF F3 lt 1000 THEN F3 F3 55 90 IF F0 lt gt F3 THEN GOSUB 500 100 V SPOLL 719 110 iF NOT BIT V 1 THEN GOTO 100 120 V SPOLL 719 130 IF NOT BIT V 1 THEN GOTO 120 140 GOTO 30 500 F0 F3 505 OUTPUT 718 CW FO MZAP7DB l 510 RETURN a Tune local oscillator to offset frequency 520 END Local oscillator address Adjust the oscilloscope to center the pulse waveform Adjust the vertical controls for a 5 division peak pulse display See Figure 4 28 b DIV Figure 4 28 Pulse Rise Fall Time and Overshoot Waveform 7 Measure the pulse rise time fall time overshoot and ringing Record the results Rise Time _ lt 80 ns Fall Time ___ 880 ns Overshoot and Ringing Ses lt 35 HP 8678C D Performance Tests PERFORMANCE TESTS PULSE RISE FALL TIME AND OVERSHOOT TEST cont d Procedure NOTE cont d For the measurements in this procedure refer to Figure 4 29 Pulse Definitions for explanations of the pulse parameters Tp Tr QOZ amen RF PULSE OUT Figure 4
66. Require Service SRQ Trigger Configuration Cleared MESSAGE Cleared set to 00 RF OUTPUT ON ALC INTERNAL RANGE 70 dB VERNIER 0 0 dBm AUTO PEAK ON MTR Scale LVL AM FM and Pulse OFF Modulation FREQUENCY FREQ INCR 1 000 MHz START 2000 000 MHz STOP 4000 000 MHz AF 2000 000 MHz MKR OFF SWEEP MODE OFF STEP 100 steps 20 000 MHz DWELL 20 ms TUNE Knob ON NORMAL BYPASS NORMAL 3000 000 MHz 3 35 Receiving the Trigger Message The Signal Generator responds to a Trigger mes sage only if a response has been pre programmed see Configure Trigger Otherwise it ignores a Trigger message It responds equally to a Trigger message with bus command GET and a Data message with program code TR Trigger Configure Trigger The Signal Generator s re sponse to a Trigger message is set when it receives a Data message containing the program code CT followed by one valid program code For example CTW6 causes a single sweep W6 when the Trigger message is received Operation 3 36 Receiving the Remote Message The Remote message has two parts First the remote enable bus control line REN is held true second the device listen address is sent by the controller These two actions combine to place the Signal Generator in remote mode Thus the Sig nal Generator is enabled to go into remote when the controller begins the Remote message but it does not actually switch to remote until addressed to listen the first time When
67. Rise time overshoot ringing and peak level accuracy are measured at 50 MHz with an oscilloscope On off ratio is measured at 50 MHz and at 6 7 GHz with a spectrum analyzer A local oscillator and mixer is used with an oscilloscope to measure peak level accuracy at 6 7 GHz and to measure rise time overshoot and ringing at 6 7 12 18 and 19 6 GHz The IF frequency used is 50 MHz Equipment Spectrum Analyzer 00 eee HP 8566B Pulse Generator e cee ee ee eeee HP 8116A Oscilloscope ni iiaires ee i eereee bores HP 1980B Local Oscillator es seduce eesaasas HP 8340A Preamplifier 20 dB 0c cece HP 8447D Power Amplifier 20 dB HP 8447E IO Ee ech a oreudeceud oxdoabiee R ced RHG DMS1 26 Attenuator 10 dB 2 ce cece cece HP 8491A Option 010 Attenuator 10 dB coeeuan eased HP 8493C Option 010 Procedure 1 Connect equipment as shown in Figure 4 4 Rise Time Overshoot and Ringing at 50 MHz 2 Press RCLO on the Signal Generator Set FREQUENCY to 50 MHz RANGE and VERNIER to 0 dBm and PULSE to NORM 3 Set pulse generator to 1 MHz PRF 200 ns width and 2V peak output level Set Channels 1 and 2 of the oscilloscope to 50 ohm input impedance 4 Center the 50 MHz RF pulse waveform on the oscilloscope display Adjust the oscilloscope vertical position and sensitivity controls so that the pulse base line is one division from the bottom graticule line and 5 divisions high in peak amplitude See Figur
68. SETTLED bit of the status byte can be monitored to determine when the new frequency has settled Once this bit is set the NOT PHASE LOCKED bit in the extended status byte may be checked to ensure that the instrument is working correctly The NOT PHASE LOCKED bit is not valid until after the SOURCE SETTLED bit has been set The current sweep stop frequency can be read by the controller using the output active program code suffix To read the stop frequency send the program codes FBOA and then read the stop frequency The Signal Generator will send the frequency in fundamental Hz units If the frequency is read as a string the format will be the program code FB followed by the sweep stop frequency in Hz and then the units terminator Hz To set the sweep stop frequency to 16 232 334 MHz Locai 1 Press the SWEEP FREQ STOP key 2 Key in 16232 334 using the numeric keypad The FREQUENCY MHz display should show 16232 334 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the MHz units key to finish the sequence The FREQUENCY MHz display should show the entered frequency until the units key is released The FRE QUENCY MHz display should now be right justified The frequency could also have been entered as 16 232334 GHz or 16232334 kHz The only difference is the placement of the decimal point and the units key pressed after the frequency has been entered using the numeric keyp
69. Stat 3 THEN GOTO 520 Wait for set bit 550 Done 560 SUBEND Source is settled or 1 second has passed Error The following message numbers may be displayed when setting the frequency incre Messages ment or changing the frequency Each error message is explained as it pertains to set ting the frequency increment or changing the frequency For a more complete descrip tion of the messages see the MESSAGES detailed operating instructions 01 Desired frequency is out of range Occurs in remote mode when a frequency decre ment would place the new frequency below the Signal Generator s frequency range 02 Entered frequency increment is not within the capability of the Signal Generator Also occurs in remote mode when a frequency increment would place the frequency above the Signal Generator s frequency range 90 Auto Peak malfunction This indicates that the instrument may require service 3 82 HP 86738C D Description Local Procedure Remote Procedure Example Operation Detailed Operating Instructions Frequency Modulation The Signal Generator provides frequency modulation at modulation indexes up to 5 for frequencies below 6 6 GHz 10 for frequencies between 6 6 and 12 3 GHz 15 for frequen cies between 12 3 and 18 6 GHz and 20 for frequencies above 18 6 GHz The FM modula tion index is the peak deviation divided by the modulating rate FM peak deviation is linearly controlled by the signal at the FM IN connecto
70. TEST FAILURE A2A11 99 RAM NOT FUNCTIONAL AT POWER UP 11 10 START FREQ STOP FREQ No sweep For non system compatible Signal Generators 03 BYPASS NOT FUNCTIONAL BELOW 2 0 GHz To determine system compatibility see paragraph 3 2 3 101 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure Remote Procedure 3 102 Multiplier Mode Display multiplier mode is available on system compatible Signal Generators only See paragraph 3 2 System Compatibility for more information Display multiplier mode provides direct output frequency display of a system of instruments The system may be composed of the Signal Generator and a frequency multiplier or a combination of equipment that produces an integer multiple of the Signal Generator s RF output frequency By entering the multiplying factor the Signal Generator can be used to directly display and control the output of the system as long as a linear relationship exists between the Signal Generator RF output frequency and the output frequency of the system Once the multiplier is entered a front panel annunciator lights to indicate that the displayed frequency is not equal to the actual RF output frequency All frequencies except frequency offset will be displayed after being multiplied by the entered multiplier For example with a multiplier of 2 entered an actual RF output frequency of 3 GHz will be displayed as 6 GHz Entering 6 GH
71. TR a Data message Sets output to 3000 000 MHz at 70 dBm with sweep and modulation off Resets many additional parameters as shown in Table 3 5 Responds equally to Device Clear DCL and Selected Device Clear SDC bus commands DCL DC1 SDC REN RL1 Remote mode is enabled when the REN bus control line is true However remote mode is not entered until the first time the Signal Generator is addressed to listen The front panel RMT annunciator lights when the instrument is actually in the remote mode RLI responds equally to the Go To Local GTL bus command and the front panel LOCAL key i Local Yes The LOCAL key is disabled Only the controller can return the Signal LLO RLI Lockout Generator to local front panel control Clear The Signal Generator returns to local front panel control and local REN RLI Lockout Set Local lockout is cleared when the REN bus control line goes false The Signal Generator has no controller capability The Signal Generator sets the SRQ bus control line true if one of the fol lowing conditions exists and it has been enabled by the Request Mask to send the message for that condition Front Panel Key Pressed Front Panel Entry Complete Change in Extended Status Source Settled End of Sweep Entry Error and Change in Sweep Parameters i PA Pe PA arer ttt SRAAAEM HAVANA ARANETA RH The Signal Generator responds to a Serial Foll Enabl
72. W2 Auto sweep mode 70 CASE MANUAL 80 Code W3 90 CASE SINGLE ONCE 100 Code W6 Arm and begin single 110 CASE ELSE 3 91 Operation HP 86738C D Detailed Operating Instructions Programming Example confd Error Messages 3 92 Manual Sweep Mode conta 120 DISP WARNING invalid sweep mode specified 130 Err 1 140 SUBEXIT 150 END SELECT 160 170 OUTPUT 719 USING 2A Code 180 190 SUBEND f End of subroutine The following message numbers may be displayed when activating manual sweep mode Each message is explained as it pertains to activating manual sweep mode Fora more complete description of the ences see the MESSAGES detailed operating 10 H 12 16 90 instructions The start and stop frequency are set to the same value No sweep will be generated The current sweep span is set such that the start frequency would be below the frequency range of the instrument The sweep will begin at the lowest sweep point that is within the range of the Signal Generator All sweep points will be allotted but the frequency will not change until the sweep is within the frequency range of the Signal Generator The current sweep span is set such that the stop frequency would be above the frequency range of the instrument The sweep will end at the highest sweep point thatis within the frequency range of the Signal Generator All sweep points will be allotted
73. a change of 3 GHz the 1 GHz digit Typical switching times by largest digit being changed for frequencies less than 6 6 GHz can be summarized as follows Largest Digit Time to be Changed Within 1 kHz 100 MHz 10 MHz 1 MHz 100 kHz 10 kHz 1 kHz Frequencies above 6 6 GHz are produced by multiplying the baseband 2 0 6 6 GHz frequency For frequency changes involving frequencies above 6 6 GHz the actual frequency digits being changed must be determined by dividing the frequency change by two 6 6 to 12 3 GHz three 12 3 to 18 6 GHz or four 18 6 to 26 5 GHz The result will indicate which digits of the fundamental unmultiplied frequency will actually change The frequency switching time will depend only on which digits of the baseband frequency are changing For applications that require fastest execution the SOURCE SETTLED bit of the status byte can be used Once the bit is set after a frequency has been incremented or decremented the output is valid and the program may continue If the frequency is changed and the status byte is not checked the program should wait at least the frequency switching speed time specification before assuming the output valid For controllers with buffered output capability an additional wait is required to ensure that the frequency switching time plus the time required for the Signal Generator to receive the program string has elapsed before assuming the RF output is valid 3 79 Operation
74. actually in remote the Signal Generator s front panel RMT annun ciator lights 3 37 Receiving the Local Message The Local message is the means by which the controller sends the Go To Local GTL bus com mand If addressed to listen the Signal Generator returns to front panel control when it receives the Local message When the Signal Generator goes to local mode the front panel RMT annunciator turns off However even when in local if the Signal Generator is being addressed its front panel LSN or TLK annunciator turns on 3 38 Receiving the Local Lockout Message The Local Lockout message is the means by which the controller sends the Local Lockout LLO bus command If in remote the Signal Generator responds to the Local Lockout Message by dis abling the front panel LOCAL key The local lock out mode prevents loss of data or system control due to someone accidentally pressing front panel keys If while in local the Signal Generator is enabled to remote that is REN is set true and it receives the Local Lockout message it will switch to remote mode with local lockout the first time itis addressed to listen When in local lockout the Sig nal Generator can be returned to local only by the controller using the Local or Clear Lockout Set Local messages by setting the LINE switch to STBY and back to ON or by removing the bus cable 3 39 Receiving the Clear Lockout Set Local Message The Clear Lockout Set Loca
75. and down keys The tuning step willbe equal to the frequency increment or the tuning resolution whichever is greater For frequency increments that are not a multiple of the frequency resolution the tuning occurs in a way to make the average tuning increment equal to the frequency increment See the comments section for more information about frequency increments that are not a multiple of the frequency resolution HD 8673C D Local Procedure cont d Remote Procedure Example Operation Detailed Operating Instructions Frequency Increment and Tuning conta If a sweep mode is active when the frequency increment is entered the frequency displayed after releasing the units key will be either the current RF output frequency or the start and stop frequency of the sweep Tuning the frequency during single or auto sweep mode changes the sweep center frequency in steps equal to the frequency incre ment In auto sweep mode the sweep will continue about the new center frequency In single sweep mode the sweep will reset to the new start frequency and remain armed In manual sweep mode tuning the frequency has the effect of changing the RF output frequency by the sweep step size The frequency increment is not used during manual sweep mode To check the current frequency increment press and hold the FREQ INCR key The FREQUENCY MHz display will display the frequency increment as long as the key is held The Signal Generator
76. and the calculated start and stop frequencies are rounded off The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The following program is used to set the Signal Generator sweep center frequency to the frequency specified by the variable Expected The desired value must be in MHz and should be within the frequency range of the Signal Generator 10 SUB Center_freq_set Err Expected Expected frequency in MHz 20 OUTPUT 719 USING 2A MG Read message from 8673 30 ENTER 719 USING 2A Message to clear any old messages 40 Frequency iNT Expected 1000 1000 Round off to nearest kHz 50 OUTPUT 719 USING 4A 5D DDD 2A CF Frequency MZ 60 OUTPUT 719 USING 2A MG Check for message from 8673 70 ENTER 719 USING 2A Message 80 SELECT VAL Message 90 CASE 1 Frequency was out of range 100 Err 1 110 DISP WARNING Attempt to set frequency out of range 120 CASE ELSE 130 Err 0 Other errors not applicable 140 END SELECT 150 160 OUTPUT 719 USING 4A CFOA Requests center frequency 170 ENTER 719 USING K Set_freg Frequency in Hz 180 Set_freq iINT Set_freq 1000 1000 Convert to MHz 190 200 IF ABS Set_freq_Frequency gt 001 AND Err 0 THEN 210 DISP WARNING Programmed frequency is incorrect 220 END IF 230 SUBEND End of subroutine Operation Error Messages HP 8673C D Detailed Operating Instructions Center
77. attenuation attempted operation beyond maximum power specification The VERNIER and RANGE settings and the RF output level the sum of the VERNIER and RANGE settings can be read by the controller using the output active program code suffix To read the VERNIER setting 12 0 to 3 dBm send the program string VEOA and then read the VERNIER setting The Signal Generator will send the setting in units of dBm If the setting is read as a string the format will be the program code VE followed by the setting in dBm and then the units code DM The RANGE setting is read by sending the program string RAOA and then reading the RANGE setting The Signal Generator will send the range in units of dB 90 to 20 dB If the RANGE setting is read as a string the format will be the program code RA followed by the RANGE setting in dB and then the units code DM The RF output levelis read by sending the program string LEOA and then reading the output level The Signal Generator will send the range in units of dBm 102 to 23 dBm Ifthe RF level is read as a string the format will be the program code LE followed by the system RF level and then the units code DM The program code AP or PL can be used instead of LE but the program code sent by the Signal Generator will always be LE To set the Signal Generator to system leveling using an external system compatible amplifier Local 1 Connect the amplifier to the output of the Signal Generator 2
78. bands are defined as 6 6 12 3 GHz for band 2 12 3 18 6 GHz for band 3 and 18 6 26 GHz for band 4 When using a frequency increment that is less than the specified frequency resolution there will be hysteresis about the band crossing points For example ifthe frequency increment is set to 1 kHz and the frequency is incremented from below 6 6 GHz to at least two increments above 6 6 GHz tuning back to 6 6 GHz will leave the 6 6 GHz output in band 3 instead of band 2 Incrementing less than one increment past a band point will leave the band point in the lower band When tuning upward from the 6 6 GHz band point with 1 kHz resolution the first increment will change the frequency to 6 6000002 GHz The second increment will not change the frequency but tuning back to 6 6 GHz will leave the 6 6 GHz frequency in band 2 This hysteresis will affect subharmonics the 2 6 6 GHz fundamental feedthrough and multiples of the subharmonics The Signal Generator has several frequencies where mechanical switches are actuated to change the internal microwave signal path When a frequency change crosses one of these switch points the RF output is blanked disabled to eliminate transients of the switching process The actual frequency change will still occur as described above but the RF output will be blanked for approximately 20 milliseconds during the frequency change For this reason frequency changes across one of the switch points will require a l
79. code for diode ALC is C2 Once the calibration is complete the level can be remotely controlled by programming the VERNIER to the appropriate level Changing the range while using external diode leveling will have no affect on the level but can force the Signal Generator to lose control of the level due to insufficient attenuation lack of ALC dynamic range or too much attenuation attempted operation beyond maximum power specification The VERNIER setting can be read by the controller using the output active program code suffix To read the VERNIER setting send the program string VEOA and then read the VERNIER setting The Signal Generator will send the VERNIER setting in units of dBm If the setting is read as a string the format will be the program code VE followed by the VERNIER setting in dBm and then the units code DM To set the Signal Generator to diode leveling over the range of 10 to 0 dBm using a 20 dB directional coupler Local 1 Connect the coupler to the point where the RF power is to be leveled Connect the diode to the coupled port of the 20 dB directional coupler 2 Connect a power meter to the output of the directional coupler to monitor the actual power at the leveling point 3 Press the ALC DIODE key on the Signal Generator and set the Signal Generator range to 10 dB The ALC UNLEVELED annunciator may come on when the diode leveling mode is activated The calibration in the next step will eliminate this indi
80. display will indicate that a sweep is in progress with a start stop frequency display or a running indication of the RF output frequency If a new center frequency is entered when automatic sweep mode is active the sweep will begin at the center of the sweep the new center frequency and continue sweeping Tuning the frequency will also move the sweep center frequency when automatic sweep mode is active HP 8673C D Local Procedure Cont d Remote Procedure Example Program Codes Comments Operation Detailed Operating Instructions Auto Sweep Mode conta If another sweep mode was enabled when auto sweep is selected the first sweep will begin at the current RF output frequency Subsequent sweeps will begin at the sweep start frequency If an amplifier or filter band crossing is encountered during an automatic sweep only one sweep will be executed The message key will ight and a message number will be issued to indicate that a band crossing has occurred This feature is included to prevent excessive wear on internal mechanical switches Automatic sweep mode is activated with the program code W1 The sweep can be reset with the program code RS Resetting the sweep will restart the automatic sweep at the start frequency The controller can monitor the END OF SWEEP bit of the extended status byte to determine when each sweep is finished The bit will be set when the stop frequency is reached and will not be reset un
81. for Entry error 32 and status change 4 120 PPOLL CONFIGURE 719 1 8 Line one with positive sense 130 OUTPUT 719 USING 2A B RM Mask Enable bits 140 SUBEND 150 SUB Poll_bus 160 Bus PPOLL 7 170 IF BIT Bus 1 THEN CALL Err_8673 Routine will serial poll 180 SUBEND 190 SUB Err_8673 200 V SPOLL 719 210 IF BIT V 5 THEN Entry error occurred 220 DISP Entry error occurred for HP 8673 Press MESSAGE key 230 PAUSE 240 OUTPUT 719 MG IClear message to prevent more requests 250 ENTER 719 Dummy 260 DISP Clear display line 270 END IF 280 IF BIT V 2 THEN Change in extended status is indicated 290 OUTPUT 719 0S 300 ENTER 719 USING B B Stat1 Stat2 310 IF BIT Stat2 0 THEN PRINT HP 8673 Self Test Failed 320 IF BIT Stat2 1 THEN PRINT HP 8673 FM is overmodulated 330 IF BIT Stat2 3 THEN PRINT HP 8673 is using External Ref 340 IF BIT Stat2 4 THEN PRINT HP 8673 is not phase locked 350 IF BIT Stat2 5 THEN PRINT HP 8673 has had a power failure 360 IF BIT Stat2 6 THEN PRINT HP 8673 is not leveled 370 END iF 380 SUBEND All messages except NO ERROR will set the ENTRY ERROR bit of the status byte Error 95 through 99 are related to the self test performed at power up If one of these errors is reported and the instrument is still functional the SELF TEST FAILED bit in the extended status byte will be set 3 143 Operation HP 86738C D Detailed
82. for a power meter reading of 8 dBm Tune the Signal Generator in 100 MHz steps from 2 0 GHz to 16 0 GHz while observing the power meter readings Ensure that the specified maximum leveled output power level is met Refer to the table below Tune the Signal Generator to 16 0 GHz Repeat steps 9 through 19 starting at 16 0 GHz with 200 MHz steps Use NORMAL BYPASS switch settings and output levels listed in the table below 4 49 Performance Tests HP 8673C D PERFORMANCE TESTS OUTPUT LEVEL AND FLATNESS TESTS cont d Procedure cont d Signal Frequency Minimum Specified Worst Case L Generator Range Power Level Frequency HP 8673C NORMAL BYPASS 2 0 dBm 5 0 dBm 16 0 18 0 GHz 16 0 18 0 GHz HP 8673D NORMAL 16 0 26 0 GHz BYPASS 16 0 26 0 GHz 6 0 dBm 7 0 dBm Level Flatness Test NOTE The flatness specification for power output is not referenced to a partic ular frequency The specification represents the total power variation over the entire frequency range 21 Tune the Signal Generator to 50 0 MHz Set the OUTPUT LEVEL RANGE to 0 dB Adjust the VERNIER for a power meter reading of 5 dBm 22 Set the power meter mode to dB Relative 23 Tune the Signal Generator from 50 0 MHz to 2 0 GHz in 50 MHz steps while observ ing the power meter readings Record the minimum and maximum output power levels in the following table Maximum power variation must be withi
83. for tuning over a specific range or observing several frequencies the tuning controls allow convenient control for setting frequency Tuning with the TUNING knob is useful for observing a range of frequencies and still being able to speed up or slow down the tuning as desired In addition the frequency increment may be decreased if finer resolution is desired around a specific frequency The frequency increment step keys are very useful for tuning between channels with a fixed channel spacing Setting the frequency increment to the channel spacing allows easy stepping with a single key press In addition holding down the frequency increment step key will allow stepping at a rate of about ten steps per second This power tune feature does not offer as much control as the TUNING knob because the stepping rate is fixed for the frequency increment step keys Signal Generator frequency settings can be stored in memory for later use The nine store recall registers of the Signal Generator allow up to nine different front panel settings to be stored and recalled This feature is useful when several unrelated frequencies are required i To set the Signal Generator to a specific frequency 1 Press the FREQUENCY key to indicate that the next entry will be for CW frequency 2 Enter the desired frequency using the numeric keypad If a mistake is made while entering the frequency press the backspace key until the incorrect digit disappears
84. lowest deviation range and the peak is performed after a brief settling time l Auto Peak will slow the effective sweep time for low dwell settings The Auto Peak operation will occur every 20 MHz during sweep modes With FM selected the effective sweep time will be reduced further Auto Peak may be disabled during sweep modes at the expense of maximum available power and modulation performance Pulse modu lation requires a longer auto peak operation to maintain pulse performance Therefore pulse modulation while sweeping will dramatically lengthen sweep time The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program will execute an Auto Peak operation and then return after the Auto Peak operation is complete HP 8673C D Programming Example cont d Error Messages Operation Detailed Operating Instructions Auto Peak conva 10 SUB Peak Err 20 OUTPUT 719 USING 4A CSK1 Force an Auto Peak and enabie peaking 30 40 V SPOLL 719 50 IF NOT BIT V 3 THEN GOTO 40 Wait for completed Auto Peak 60 70 OUTPUT 719 USING 2A MG Check for error 80 ENTER 719 USING 2A Message 90 IF Message 90 THEN 100 Err 90 110 ELSE 120 Err 0 130 SUBEND If an Auto Peak operation cannot be performed due to low power output or a mistuned filter error message 90 will be issued to indicate that service is required 3 51 Operation HP 8673C D Detailed Operati
85. memory Subsequent operation at this VERNIER setting will use the scratch pad data instead of performing another Auto Peak operation By sweeping the VERNIER over the entire ALC range 10to 3 dBm on the 0 and 10 dB ranges the scratch pad memory will be filled with the required parameters for the pulse injection circuitry Once the scratch pad memory contains the data for the current frequency an Auto Peak operation will not occur for any change in RF output level A frequency change will erase the scratch pad memory so this process must be repeated at the new frequency 3 117 Operation HP 8673C D Detailed Operating Instructions Comments contd Programming Example Error Messages 3 118 Pulse Modulation conta Pulse modulation uses a sample and hold system to maintain pulse level accuracy A capacitor is used to hold the automatic level control ALC circuit setting between pulses to reduce the time required for output level settling at the next pulse When pulse and amplitude modulation are used together the capacitor has the effect of reducing the effective AM bandwidth The reduction in AM bandwidth is explained under AM detailed operating instructions When pulse modulation is selected with no input pulse the level meter will drift This is a normal occurrence due to the limitations of the sample and hold circuitry Due to the Auto Peak operations performed during pulse modulation frequency switching time is sl
86. messages see the MESSAGES detailed oper ating instructions 10 Thestart and stop frequency are set to the same value No sweep will be generated 11 The current sweep span is set such that the start frequency would be below the frequency range of the instrument The sweep will begin at the lowest sweep point that is within the range of the Signal Generator All sweep points will be allotted but the frequency will not change until the sweep is within the frequency range of the Signal Generator 12 The current sweep span is set such that the stop frequency would be above the frequency range of the instrument The sweep will end at the highest sweep point thatis within the frequency range of the Signal Generator All sweep points will be allotted but the last sweep points will all be at the highest valid frequency 16 A filter or amplifier band crossing occurred during automatic sweep mode Only one sweep will occur and then the sweep will stop Filter switch points may be eliminated by using BYPASS mode 90 Auto Peak malfunction This indicates that the instrument may require service 3 55 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure 3 56 Center Frequency Sweep The sweep center frequency is used in conjunction with the sweep delta frequency to set the frequency sweep limits The sweep frequency limits can also be set using the sweep start and stop frequencies Setting the sweep sta
87. meters are given in the following tables HP 432A B and HP 435B ALC Typical Settling Times Power Sensor Power Meter Range dBm 10 dB Step to Within 1 dB Power Step Response i HP 432 20to 10 HP 478A 400 ms Overdamped HP 435 10to 20 HP 8485A 550 ms Critically Damped 15 9 38 Underdamped 5s Underdamped Unstable HP 436A ALC Typical Settling Times Power Meter Power 10 dB Step te Step Range dBm Sensor Within 1 dB Response 0 to 20 HP 8485A Critically Damped 10 s Underdamped 20 Unstable 40 to 20 HP 8484A Critically Damped 50 g Underdamped 70 to 60 Unstable Power 10 d8 Step to Step Sensor Within 1 dB Response HP 8485A 200 ms Critically Damped j 4s Underdamped HP 8484A 200 ms Critically Damped L As Underdamped 3 113 Operation HP 8673C D Detailed Operating Instructions Comments cont d Application Example 3 114 Power Meter Automatic Level Control conta The HP 488A auto filter mode will select filters automatically depending on range Using the manual filter mode can provide faster ALC settling time The Signal Generator range selected will have a direct affect on ALC The range selected depends primarily on the losses and gains in the RF signal path In most applications the ALC dynamic range is limited by the maximum RF power available at a
88. mode Display the value of V 30 DISP V DISP V 40 END Operator s Check that the SRQ annunciator is on and that the response to the parallel poll is 0 Response indicating that Signal Generator is no longer configured to respond to a parallel poll Then turn the LINE switch to STBY then to ON to turn the SRQ annunciator off Trigger Message Note This check determines if the Signal Generator responds to the Trigger message Series 200 306 HP 858 BASIC Send the Remote message REMOTE 719 REMOTE 719 Send a Data message to set the OUTPUT 719 OUTPUT 719 Signal Generator s frequency to FR 9999 MZ FR 9999 MZ 9999 MHz Set the Signal Generator s fre OUTPUT 719 OUTPUT 719 quency increment to 1111 MHz FI 1111 MZ FY 1111 MZ 3 29 HP 86738C D OPERATOR S CHECKS HP iB Functional Checks cont d Trigger Message contd Operaior s Check that the Signal Generator s frequency is set to 9999 MHz Then press the Signal Response Generator s FREQ INCR key to check for an increment of 1111 MHz This keyboard function is possible in the remote state even if local lockout is enabled Configure the Signal Generator s OUTPUT 719 CT DN OUTPUT 719 CT DN trigger response to be an INCRE MENT down function that is DN Send a Trigger message TRIGGER 719 TRIGGER 719 Operator s Check that the Signal Generator s frequency changes to 8888 MHz Response 3 30 HP 86
89. modulation rates fall between 100 Hz and 10 MHz Pulse modulation has two operating modes NORM normal mode and COMPL complement mode In normal mode the RF output is On when the drive signal is the TTL high state In the comple ment mode the RF output is On when the drive signal is in the TTL low state The Signal Generator is compatible with HP IB to the extent indicated by the following code SH1 AH1 T5 TEO L3 LEO SR1 RL1 PP1 DC1 DT1 and CO The Signal Generator interfaces with the bus via three state TTL circuitry An explanation of the compatibility code can be found in IEEE Standard 488 1978 IEEE Standard Digital Interface for Programmable Instrumentation or the identical ANSI Standard MC1 1 For more detailed information relating to programmable control of the Signal Generator refer to Remote Operation Hewlett Packard Interface Bus in Section II of this manual 1 6 OPTIONS 1 7 Electrical Options Option 001 The internal 10 dB step attenuator has been deleted The specified output level is listed in Table 1 1 1 4 HP 8673C D Option 002 The internal 10 MHz crystal reference is removed An external 5 or 10 MHz reference must be used Option 003 A special fan allows operation from 400 Hz power mains as well as 50 60 Hz Option 004 The Signal Generator s RF OUTPUT connector is located on the rear panel Maximum output power is listed in Table 1 1 Option 005 The Signal Generator
90. of LE but the program code returned from the Signal Generator will always be LE To set the Signal Generator to an output level of 16 dBm Local 1 Press the ALC INT key on the Signal Generator to set the leveling to internal 2 Set the Signal Generator RANGE to 10 dB The VERNIER can be adjusted for levels between 20 and 7 dBm in the 10 dB range HP 8678C D Example cont d Program Codes Comments Programming Example Operation Detailed Operating Instructions internal Automatic Level Control contd 3 Adjust the VERNIER for a 6 dBm reading on the LEVEL meter This sets the output level to 16 dBm Remote The program string to set the ALC mode and the output level is CILE 16DM Addi tional information on setting the output level can be found under RANGE and VERNIER detailed operating instructions Program Code Description Internal Automatic Leveling Control Internal ALC is used to control the internal RF signal over arange of 10 to 13 dBm Additional dynamic range is provided by a 90 dB step attenuator to give an effective dynamic range of 100 dBm to 13 dBm The actual maximum leveled power available is dependent on the frequency and varies for the different frequency bands An ALC UNLEVELED condition occurs when the internal ALC circuitry cannot maintain leveling This can occur due to an instrument fault or because the instrument is set to level for an RF output
91. output levels above the specified maximum leveled power may not be available at all frequencies Programming the RF output level can be done in one of two ways The RF output level can be programmed directly using the program code LE AP or PL The units terminator for the output level is dBm which corresponds to the program code DM The Signal Generator will also accept the program code DB as the terminator When programming the RF output level the VERNIER is set between 0 and 9 9 dBm and the RANGE is set accordingly 3 159 Operation HP 86738C D Detailed Operating Instructions Remote Procedure cont d Example 3 160 Vernier Output Level conta The RF output level can also be programmed by programming the VERNIER and the RANGE separately The program code to set the RANGE is RA and the program code to set the VERNIERis VE The units terminator for both codes can be either DB or DM The output active program code suffix can be used to read the current values of the RANGE VERNIER or the RF output level directly To read the RANGE setting send the program codes RAOA and then read the RANGE setting The Signal Generator will send the RANGE in fundamental dBm units If the RANGE is read as a string the format will be the program code RA followed by the RANGE in dBm and then the units terminator DM dBm In local mode the Signal Generator keeps track of the VERNIER setting to within 0 1 dB When switching to remote
92. remote VERNIER is setin 0 1 dBm steps A selec tion of programming codes allows either com bined or independent setting of the RANGE and VERNIER power The entry format is Program Code Numeric Value Units Terminator The code LE sets both range and vernier The code RA sets just the range The code VE sets just the vernier In going from local to remote the output level might change by a fraction of a dB In going from remote to local the front panel knob takes control There is no assurance of whether the power will go up go down or stay the same 3 31 Data Messages The Signal Generator communicates on the inter face bus primarily with Data messages Data messages consist of one or more bytes sent over the bus data lines when the bus is in the data mode attention control line ATN false Unless it is set to Talk Only the Signal Generator receives Data messages when addressed to listen Unless it is set to Listen Only the Signal Generator sends Data messages or the Status Byte message when addressed to talk Virtually all instrument opera tions available in local mode can be performed in remote mode via Data messages The major excep tions are changing the LINE switch settings and changing the HP IB address of the Signal Generator 3 32 Receiving Data Messages The Signal Generator responds to Data messages when it is enabled to remote REN control line true and it is addressed to listen The instrument remain
93. respective units g For SINGLE Mode On Master Unit press SINGLE once to enable the sweep Press it a second time to start one sweep If SINGLE is pressed during a sweep the in progress sweep stops and re enables Disabling Master Slave Mode Press SWEEP OFF on both Master and Slave Units Set instrument HP IB addresses to their previous settins All sweep indicators will be off The Master Unit TUNE Knob will now cause changes only on the Master Unit Display Operation HP 8673C D py Bete FREGUENGY MRI P E ZL 500000 4 RANGE dBm Display Indicates the selected range of the to 12 3 GHz 15 12 3 to 18 6 GHz or 20 18 6 to RF output in 10 dB steps from 90 to 10 dB Range is 26 0 GHz The modulation index is equal to the set by the RANGE 4 gt and s keys maximum peak deviation divided by fog Refer Meter Monitors power level AM depth or FM devia aay 1 1 Specifications for additional infor tion Meter function is selected by the MTR keys i 6 MTR Keys Select the meter function STANDBY lights when power is applied but the 3 8 LVL selects OUTPUT LEVEL VERNIER for 10 to 3 dBm scale indication Read relative to the RANGE dB display AM selects 30 read on the 0 to 3 scale or 100 read on the 0 to 1 scale AM depth fuli scale A 1 volt peak signal applied to the AM IN connector develops full scale modulation FM selects FM deviation Full scale indication read on the 0 to 3 scale is 30 k
94. s RF OUTPUT connector is located on the rear panel and the attenuator is removed This combines Options 001 and 004 The specified output level is listed in Table 1 1 1 8 Mechanical Options The following options may have been ordered and received with the Signal Generator If they were not ordered with the original shipment and are now desired they can be ordered from the nearest Hewlett Packard office using the part numbers included in each of the following paragraphs Option 006 Chassis Slide Mount Kit This kit is extremely useful when the Signal Generator is rack mounted Access to the internal circuits and components or the rear panel is possible without removing the Signal Generator from the rack The Chassis Slide Mount Kit part number is 1494 0058 An adapter HP part number 1494 0023 is needed if the instrument rack mounting slides are to be mounted in a non HP rack the slides without the adapter can be directly mounted in the HP system enclosures Option 908 Rack Flange Kits The Signal Genera tor can be solidly mounted to the instrument rack without handles using the flange kits The Rack Flange Kit part numbers are 5061 0074 and 5061 0077 Both kits are required Option 913 Rack Flange Kit for Instruments with Handles The Signal Generator can be rack mounted with existing handles using this kit The HP part number for this Rack Flange Kit is 5061 0085 1 9 ACCESSORIES SUPPLIED The accessories suppli
95. set between 1 kHz and the currently defined sweep span as long as the calculated number of steps is between 1 and 9999 steps Entering a sweep step size larger than the sweep span will set the step size equal to the span and will cause the Signal Generator to issue a message To set the sweep step size 1 Press the STEP key to indicate that the next entry will be for the sweep step size or the number of steps The only difference in entering the two is the units terminator 2 Enter the desired sweep step size using the numeric keypad If a mistake is made while entering the frequency press the backspace key until the incorrect digit disappears Continue entering the correct digits until the sweep step size in the FREQUENCY MHz display is correct 3 Press the appropriate units key You may enter the sweep step size in GHz MHz or kHz Once the units key is pressed the sweep step size will be adjusted to read in MHz and the sweep step size will continue to be displayed until the units key is released If the entered value does not result in at least one step and less than 9999 steps the step size will be adjusted until the Signal Generator is capable of performing the sweep The entered value is retained for use when other sweep parameters are changed This feature enables the sweep parameters to be entered in any order with restrictions due to previous sweep parameters not affecting the final values For example if the sweep step sizeis en
96. signal can be connected to the AM IN connector on the front panel to provide AM markers on the external display Nominalimpedance of the TONE MKRis 600 ohms The BLANKING MARKER output provides a 5 volt signal at the beginning of each frequency change for blanking an external display The blanking function is used to eliminate the display of switching transients Once the frequency has settled the signal returns to 0 volts unless the new frequency is an active marker frequency If the frequency is an active marker frequency the signal is set to 5 volts to provide a Z axis input for intensifying the display at the marker sweep point The PENLIFT connector provides control for an external X Y recorder and is only active during single sweep mode A TTL logic high is used to raise the pen and a TTL logic low is used to lower the pen The pen is only lowered in single sweep and thereisa 100 millisecond sweep delay for the pen to raise or lower To set the Signal Generator for manual sweep mode 1 Set the desired sweep parameters The tuning controls will change the current sweep frequency by the sweep step size and not by the current frequency increment 2 Press the MANUAL SWEEP MODE key to activate manual sweep mode The key indicator will light and the frequency will be set to the start frequency Using the FREQ INCREMENT up or down key or the TUNE knob will change the RF frequency by the sweep step size 3 89 Operation HP 8678C D
97. that is equal to or greater than the specified resolution This adjustment also occurs when the selected number of steps would produce a sweep step size that is not a multiple of the 1 kHz minimum frequency resolution For example a frequency span of 350 kHz with 140 steps would require a 2 5 kHz step size The Signal Generator would use 175 steps of 2 kHz to produce a step size that is a multiple of 1 kHz HP 8678C D Description Local Procedure Remote Procedure Operation Detailed Operating Instructions Step Size Sweep The Signal Generator performs a sweep by stepping the RF output frequency in discrete steps between the start and stop frequency of the sweep The number of steps that the Signal Generator makes between the start and stop frequency is set by the number of steps or the sweep step size Setting the number of steps in a sweep will change the sweep step size and setting the sweep step size will change the number of steps Sweep step size is calculated by dividing the frequency span AF by the number of steps when the number of steps is set The number of steps is set by dividing the frequency span AF by the sweep step size when the sweep step size is entered The Signal Generator is capable of 1 to 9999 steps within a sweep span as long as the calculated step size is greater than 1 kHz For a sweep with one step the Signal Generator will produce the start frequency and the stop frequency Sweep step size can be
98. that the internal phase lock loops remain phase locked across their tuning range The actual frequency at the RF OUTPUT connector is not checked However this connector can be monitored with a microwave frequency counter or spectrum analyzer for greater assurance that the Signal Generator is operating properly 9 Press RCL 0 10 Set the Signal Generator frequency to 1 000000 GHz and FREQ INCRMENT to 1 111111 GHz 3 17 Operation HP 8673C D OPERATOR S CHECKS Basic Functional Checks contd Procedure 11 contd 12 Step the Signal Generator from 1 000000 GHz to 11 000000 GHz in 1 111111 GHz steps Verify that the UNLOCKED annunciator remains off at each step NOTE Fast stepping or tuning of frequency may cause the o UNLOCKED annunciator to flash on momentarily This is normal and does not indi cate a malfunction Also note that some steps will not exactly equal 1 111111 GHz depending upon the resolution of each frequency band Set FREQUENCY to 10 MHz and then to 18 6 GHz HP 8673C or 26 5 HP 8673D Verify that the UNLOCKED annunciator remains off at both frequencies Output Level Check The Signal Generator s internal Automatic Leveling COntrol ALC is checked to ensure that it remains leveled at all specified power levels The ALC monitors most of the RF output circuitry 13 14 19 20 21 22 23 3 18 Press RE 0 to set the Signal Generator to a known state Connect a
99. the table Repeat step 10 using the FM deviation ranges and test oscillator levels listed in the table below Record the readings in the table FM Test Oscillator Actual Deviation Lavel imi Deviation Range 0 03 MHz 0 707 Vrms 27kHz 0 1 MHz 0 707 Vrms 90 kHz 0 3 MHz 0 707 Vrms 270 kHz 1 MHz 0 212 Vrms 249 kHz Tune the Signal Generator to 6 7 GHz Set the FM DEVIATION range to 0 3 MHz Tune the local oscillator to 7 2 GHz Set the test oscillator s output level to 0 707 Vrms as read on the digital voltmeter Read the FM deviation on the measuring receiver Verify that the measured deviation is within the limits shown in the table below Record the readings Repeat steps 12 through 15 using the Signal Generator frequencies listed in the table below Record the readings Signal Local Generator Oscillator Frequency Frequency Actual Deviation 7 2GHz 270 kHz e ad Sa 12 9 GHz 270 kHz 1 330 kHz 19 1 GHz 270 kHz 330kHHz 4 19 HP 8673C D Performance Tests Table 4 1 Abbreviated Performance Test Record 1 of 3 FREQUENCY RANGE AND RESOLUTION Baseband Test 50 000 MHz 2 090 000 MHz 2 280 001 MHz 2 471 112 MHz 2 662 223 MHz 2 853 334 MHz 3 044 445 MHz 3 235 556 MHz 3 426 667 MHz 3 617 778 MHz 3 808 889 MHz 3 999 999 MHz 4 180 000 MHz 4 370 000 MHz 4 560 000 MHz 4 750 000 MHz 4 940 000 MHz 5 130 000 MHz 5 320 000 MHz 5 510 000 MHz 5
100. to 707 Vrms Frequency Response 100 Hz to 100 kHz Frequency Counter Range 10 MHz to 26 5 GHz HP 5340A or Resolution 100 Hz HP 5343A 10 MHz Frequency Standard Output 2 1 Vrms Local Oscillator Range 2 GHz to 19 GHz HP 8340A Level gt 5 dBm Mixer Response 1 to 26 GHz RHG DMS1 26 VSWR LO lt 2 5 1 VSWR RF 4 0 1 Measuring Receiver Frequency Range 150 to 990 MHz HP 8902A 11722A Input Level 20 to 13 dBm Amplitude Modulation Rates 25 Hz to 25 kHz Depth to 99 Accuracy 2 at 1 kHz Flatness 0 5 Demodulated Output Distortion lt 0 3 for 50 depth lt 0 6 for 90 depth Incidental Phase Modulation lt 0 05 radians for 50 depth at 1 kHz rate 50 Hz to 3 kHz bandwidth 1 20 HP 8673C D General Information Table 1 4 Abbreviated Performance Test Recommended Test Equipment 2 of 2 instrument Measuring Receiver cont d Oscilloscope Power Meter and Sensor 20 dB Preamp 20 dB Power Amp Pulse Generator Spectrum Analyzer Test Oscillator Critical Specifications Frequency Modulation Rates 25 Hz to 25 kHz Deviation to 99 kHz Accuracy t2 at 1 kHz Bandwidth 100 MHz Vertical Sensitivity 10 mV div Vertical Input ac de or 500 de coupled External Trigger Capability Delayed Sweep Capability One Shot Digitizer Frequency Range 50 MHz to 26 GHz Input Impedance 500 SWR lt 1 25 Max Input Level 15 dBm Preamp Fre
101. units key is pressed the displayed frequency will be adjusted to display in MHz units and the sweep delta frequency will be set The sweep delta frequency will continue to be displayed until the units key is released The frequency displayed after releasing the units key may not be the same frequency displayed before the entry If sweep mode is off the displayed frequency will be the CW frequency no change If auto sweep is on the sweep will be reset and then continue using the new delta frequency If single sweep is on the sweep will be reset and the sweep will remain armed at the new start frequency If manual sweep is on the sweep frequency will be reset to the new start frequency To check the current sweep delta frequency press and hold the SWEEP FREQ AF key The FREQUENCY MHz display will display the sweep delta frequency as long as the key is held When any sweep mode is turned off the CW frequency will be set to halfway between the start and stop frequencies equal to the sweep center frequency The Signal Generator accepts any sweep delta frequency between 1 kHz and the maximum Signal Generator frequency Once the sweep delta frequency is entered the Signal Generator will recalculate the sweep start and stop frequencies If the recalcu lated start and or stop is above 6 6 GHz the calculated frequency may be rounded by the Signal Generator to be compatible with the 2 3 or 4kHz resolution at the calculated frequency see comments
102. was originally stored during remote mode the VERNIER will not affect the output level This restriction is required to allow the storage and recall of instrument states in remote mode that include the VERNIER setting A register that is stored in local mode will preserve the local VERNIER setting Recall of the register in remote mode will use the same local level VERNIER setting Remote The programming string to store the current instrument state in register 1 is ST1 To recall the register at a later time the program string RC1 would be used Sending the program string RCO or IP will preset the instrument Storage Register Codes Instrument Preset Codes Program Baie Program Lar Store Instrument State Instrument Preset Recall Instrument State Instrument Preset Recall Instrument State Alternate Preset The nine storage registers can be cleared using a special front panel key sequence This feature is useful in high security applications to destroy any instrument settings that might compromise the security To clear the storage registers press the LVL key near the front panel meter and the FM 3 MHz deviation range keys at the same time A successful initialization of all of the storage registers can be confirmed by an instru ment preset when the two keys are pressed All of the registers will be initialized to the preset state Storing a register in remote mode will store the remote VERNIER setting If this
103. within the range of the Signal Generator 3 109 Operation HP 86738C D Detailed Operating Instructions Description Local Procedure 3 110 Power Veter Automatic Level Control External ALC enables the Signal Generator to level the signal at a point other than the output of the Signal Generator The signal level must be detected using a signal splitter or directional coupler with an RF detector or power meter to provide a DC signal thatis proportional to power at the remote point The Signal Generator will adjust the signal level at the RF output connector to maintain a constant level at the point where the signal is detected External ALC also enables external devices such as amplifiers mixers and other specialized devices to be inserted into the RF signal path with control of the final output level by the Signal Generator l In applications where the external signal path has frequency dependent losses and or gains the RF signal at the end of the signal path will no longer be a constant amplitude over the Signal Generator s frequency range For example if a cable is used that has a constant 0 5 dB GHz loss a level error of 5 dB would occur after a 10 GHz frequency change The signal at the RF output connector of the Signal Generator has not changed but an extra 5dB of attenuation is introduced in the signal path when the output frequency is changed The detection of the signal level can be done using a power meter with an a
104. 0 Series 200 or 300 controllers The program will set the FM range to an appropriate setting and return the peak volt age required into 50 ohms for the FM peak deviation specified by the variable called Deviation 10 SUB Fm_deviation Err Deviation V_required Deviation is in MHz 20 30 IF Deviation lt 10 THEN 40 Dev D7 Code for 10 MHz peak deviation 50 V_required Deviation 10 in peak volts into 50 ohms 60 END IF 70 IF Deviation lt 3 THEN 80 Dev D6 Code for 3 MHz deviation 90 V_required Deviation 3 l in peak volts into 50 ohms HP 86738C D Operation Detailed Operating Instructions Frequency Modulation conra Programming 100 ENDIF Example 110 IF Deviation lt 1 THEN cont d 120 Dev D5 Code for 1 MHz deviation 130 V_required Deviation 1 In peak volts into 50 ohms 140 END IF 150 IF Deviations 3 THEN 160 Dev D4 Code for 300 kHz peak deviation 170 V_required Deviation 3 In peak volts into 50 ohms 180 END IF 190 IF Deviation lt 1 THEN 200 Dev D3 Code for 100 kHz deviation 210 V_required Deviation 1 In peak volts into 50 ohms 220 END iF 230 IF Deviations 03 THEN 240 Dev D2 Code for 30 kHz deviation 250 V_required Deviation 03 l In peak volts into 50 ohms 260 END iF 270 IF Deviation 0 THEN 280 Dev D1 Turns FM off 290 V_required 0 300 END IF 310 320 OUTPUT 719 USING 2A Dev Program range 330 SUBEND Error There are no messages associated with the setting
105. 0 Start Begin the process 110 CALL Read_power Do for this frequency 120 OUTPUT 719 USING 2A P_code Increment or decrement 130 CALL Settled t Wait for source to settle 140 OUTPUT 719 USING 2A 0K Get new frequency 150 ENTER 719 USING K Frequency This is current frequency 160 IF Frequency lt Stop AND P_code UP THEN GOTO Start Next step 170 IF Frequency gt Stop AND P_code DN THEN GOTO Start 180 190 SUBEND End of subroutine Note that the above program does not take into account the different resolution ranges and their effect on the actual step size This is usually not significant especially with large frequency increments The following program can be called to wait for a source settled indication from the Signal Generator The program will wait a maximum of 1 second before assuming the SOURCE SETTLED bit is not going to be set The status byte must be cleared 3 81 Operation HP 8673C D Detailed Operating Instructions Frequency Increment and Tuning conta Programming with the CS program code before the frequency is changed If the status byte is not Example cleared the SOURCE SETTLED bit may have been set by a previous command the bit cont d is latched until the status byte is read or cleared 500 SUB Settled 510 T_counter TIMEDATE In case no source settled 520 Stat SPOLL 719 f Serial poll 530 IF TIMEDATE T_counter gt 1 THEN Done Default of 1 second 540 IF NOT BIT
106. 0 dBm 70 dBm 74 85 dBm 5 15 dBm 80 dBm 85 05 dBm 74 95 dBm 90 dBm 95 25 dBm 84 75 dBm 4 97 Performance Tests HP 86738C D Table 4 4 Performance Test Record 8 of 13 OUTPUT LEVEL SWITCHING TIME Start Level Stop Level dBm dBm 99 0 0 0 lt 25 ms 88 0 0 0 lt 25 ms 77 0 0 0 lt 25 ms 66 0 0 0 ESR lt 25 ms 50 0 2 0 bunan lt 25 ms 40 0 0 0 lt 25 ms 30 0 0 0 lt 25 ms 20 0 4 0 lt 25 ms 10 0 2 0 lt 25 ms 9 9 8 0 lt 25 ms 8 0 6 0 lt 25 ms 9 9 0 0 lt 25 ms 7 0 3 0 lt 25 ms PULSE ON OFF RATIO 4 19 PULSE RISE FALL TIMES AND OVERSHOOT 50 000 MHz at 11 dBm Rise Fall Overshoot and Ringing 500 000 MHz at 11 dBm Rise Fall Overshoot and Ringing 1000 000 MHz at 11 dBm Rise Fali Overshoot and Ringing 1500 000 MHz at 11 dBm Rise Fall Overshoot and Ringing 2000 000 MHz at 11 dBm Rise Fall Overshoot and Ringing 4 98 HP 8673C D Performance Tests Table 4 4 Performance Test Record 9 of 13 i Para Results No 4 19 PULSE RISE FALL TIMES AND OVERSHOOT cont d 6000 000 MHz at 11 dBm Rise 40 ns Fall 40 ns Overshoot and Ringing 25 6600 002 MHz at 8 dBm Rise Cotati ok 40 ns Fall Pe 40 ns Overshoot and Ringing i ncaa 30 6600 002 MHz at 0 dBm Rise 40 ns Fall 40 ns Overshoot and Ringing 30 6600 002 MHz at
107. 0 to 16 0 GHz HP 8673C 2 to 100 dBm 16 0 to 18 6 GHz HP 8673D 6 to 100 dBm 16 0 to 26 0 GHz Bypass Mode 8 to 100 dBm 2 0to 16 0 GHz HP 8673C 5 to 100 dBm 16 0 to 18 6 GHz HP 8673D 7 to 100 dBm 16 0 to 26 0 GHz Flatness 1 00 dB 0 05 to 2 0 GHz 1 50 dB 0 05 to 6 6 GHz 2 00 dB 0 05 to 12 3 GHz 2 50 dB 0 05 to 18 6 GHz HP 8673D 3 50 dB 0 05 to 26 0 GHz Description This test checks output level maximum leveled power and output level flatness The output level test uses a power meter to verify that the specified maximum leveled output power can be generated over the full frequency range Level flatness measures the varia tion in output power level as the frequency is changed Equipment Power Meter 005 HP 436A Power Sensor ccscu sees HP 8485A HP 8673C D SYNTHESIZED SIGNAL GENERATOR POWER METER RF OUTPUT POWER SENSOR Figure 4 21 Qutput Level and Flatness Test Setup Procedure Output Level Test 1 Connect the equipment as shown in Figure 4 21 2 Zero and calibrate the power meter 3 Tune the Signal Generator frequency to 50 0 MHz 4 Set the OUTPUT LEVEL RANGE to 10 dB Adjust the VERNIER for a power 4 48 meter reading of 11 dBm HP 8678C D Performance Tests PERFORMANCE TESTS OUTPUT LEVEL AND FLATNESS TESTS cont d Procedure 5 Contd D 10 11 12 13 14 15 16 17 18 19 20 Peak the Signal Generator output with the AUTO PEAK key
108. 083 2110 0043 2 7 Power Cables BEFORE CONNECTING THIS INSTRU MENT the protective earth terminal of this instrument must be connected to the protec tive conductor of the mains power cables The mains plug shall only be inserted in socket outlets provided with a protective earth contact The protective action must not be negated by the use of an extension cord power cable without a protective conductor grounding This instrument is equipped with two three wire power cables When connected to an appropriate ac power receptacle these cables ground the in strument cabinet The power cable plugs shipped with each instrument depends on the country of destination Refer to Figure 2 2 for the part numbers of power cables available We ka N EN Vm PLUG SEV 1011 1959 24507 TYPE 12 CABLE HP 8120 2104 220 240V OPERATION A PLUG NZSS 198 AS 112 CABLE HP 8120 1369 220 240V OPERATION 220 240V OPERATION PLUG CEE7 VII CABLE HP 8120 1689 PLUG CEE22 V1 CABLE 8120 1378 CABLE HP 8120 1860 HP 8673C D Operating voltage is shown in module window SELECTION OF OPERATING VOLTAGE 1 Open cover door pull the FUSE PULL tever and rotate to left Remove the fuse 2 Remove the Line Voltage Selection Card Position the card so the line voltage appears at top left corner Push the card firmly inte the slot Rotate the FUSE PULL lever to its normal position Insert a fu
109. 1 4 Abbreviated Performance Test Recommended Test Equipment 2 1 Allowable HP IB Address Codes 3 1 Operating Characteristics 3 2 AUX Connector Functions 3 3 Message Reference Table 0 Page Figure Page 4 21 Output Level and Flatness Test 4 13 e TTT 4 48 4 15 4 22 Absolute Level Accuracy Test Setup 4 53 4 16 4 23 Output Level Switching Time Test SOU fi KRE ta dace aeewe cath ns a aaa 4 59 4 18 4 24 Output Level Switching Waveform 4 62 4 25 Level Switching Time Measurement 4 23 Waverton ax 34 jut waa aau re EEEn 4 63 4 26 Pulse ON OFF Ratio Test Setup 4 64 4 26 4 27 Pulse Rise Fall Time and Overshoot 4 29 Test SEUD i erva eiut EAA E 4 67 4 30 4 28 Pulse Rise Fall Time and Overshoot Waveform x e e x K K K K 4 68 4 31 4 29 Pulse Definitions 4 69 4 30 Pulse Peak Level Accuracy Test 4 83 SOUD v7 48 oo ste wees A A EA 4 73 4 31 Pulse Peak Level Accuracy 4 34 Measurement e e 4 74 4 32 AM Bandwidth Test Setup 4 76 4 36 4 33 AM Accuracy Test Setup 005 4 78 4 34 Incidental FM Test Setup Part One 4 81 4 40 4 35 Incidental FM Test Setup Part Two 4 82 4 36 FM Frequency Response Test Setup 4 84 4 42 4 37 External FM Accuracy and Meter Accuracy Test Setup ccc acceeee 4 87 4 45 4 38 Incidental AM Test Setup 4 89 TABLES Page Table Page 16 3 4 T
110. 1000 000 16500 000 6000 000 12000 000 18000 000 6500 000 13000 000 19500 000 20000 000 22000 000 24000 000 26000 000 HP 8673D i 4 4 Performance Tests HP 86738C D PERFORMANCE TESTS 4 13 NON HARMONICALLY RELATED SPURIOUS SIGNALS CW AND AM MODES TESTS Specification Electrical Performance Characteristics Characteristics Spurious 0 05 to lt 2 0 GHz Spurious Non harmonically Related may occur at lt 40 dBe from 10 50 MHz and at lt 55 dBc from 50 100 MHz 2 0 to 6 6 GHz 6 6 to 12 3 GHz 12 3 to 18 6 GHz HP 8673D only 18 6 to 26 0 GHz Description A spectrum analyzer is calibrated for 50 dBc and then tuned to any frequency from 0 05 to 26 0 GHz in search of spurious signals NOTE The non harmonically related spurious signals will always increase in amplitude above 6 6 GHz due to multiplication in the internal YIG tuned multiplier The increase is determined by a strict mathematical relation ship Therefore satisfactory performance in the 0 05 to 6 6 GHz range will always ensure meeting the less stringent specification in the multi plied bands that is from 6 6 to 26 0 GHz Equipment Spectrum Analyzer HP 8566B HP 8673C D SYNTHESIZED SPECTRUM ANALYZER SIGNAL GENERATOR RE OUTPUT c INPUT APC 3 5 CABLE Figure 4 19 Non harmonically Related Spurious Test Setup Procedure 1 Connect the equipment as shown in Figure 4 19 2 Tune the Signal Gener
111. 136 HP 8673C D Description Operation Detailed Operating Instructions Status Byte and Polling The status byte enables a remote controller to determine the instrument s status There is also an extended status byte which can be read by the controller to determine the state of most of the front panel annunciators Status Byte The status byte contains eight bits which correspond to certain conditions of the instrument Each bit is defined as follows BIT 1 FRONT PANEL KEY PRESSED This bit is used to indicate that one of the BIT 2 BIT3 BIT 4 front panel keys has been pressed since the last time the status byte was cleared The bit is not set if the Signal Generator is in remote mode when a key is pressed The bit can be used in applications requiring the controller to know when a user changes one of the instrument parameters For example the bit can be used to indicate when a user has changed frequency so that measuring equipment under remote control can be retuned for another measurement Changes of the VERNIER and pressing the NORMAL BYPASS key are not indicated by this bit The RANGE up and dewn keys and the FREQ INCREMENT up and down keys will have this bit set once for each key press However holding the key down will increment or decrement more than one time even though the bit is set only once FRONT PANELENTRY COMPLETE This bit is used to detect the completion of a front panel data entry using the numeric keypad
112. 14 Measure the frequency switching time by observing the digitized signal on the oscil loscope display The external trigger is the reference for determining switching speed The switching time is measured from the display s left graticule to the last phase reversal as the Signal Generator frequency passes the local oscillator frequency before the IF signal settles into a steady frequency Refer to Figure 4 14 Record the frequency switching time NOTE With the oscilloscope in delayed sweep mode the left graticule of the display corresponds to the delay time This delay must be added to the time from the left graticule to the last phase reversal to obtain the frequency switching time lt 50 ms 15 Repeat steps 5 through 12 for each of the start and stop frequencies listed in the following table Record the switching time for each indicated frequency change Amplitude Recovery Time 16 Set the local oscillator to 6 599 999 MHz 17 Set the Signal Generator start frequency to 2 000 000 MHz and stop frequency to 6 600 000 MHz 4 31 Performance Tests HP 86738C D PERFORMANCE TESTS FREQUENCY SWITCHING TIME TEST cont d Procedure contd 4 32 18 19 20 ai 22 23 Start Frequency MHz 3 000 000 4 000 000 18 000 000 6 200 000 6 000 000 6 500 000 6 490 000 1 900 000 2 200 000 2 100 000 6 610 000 6 590 000 3 999 000 HP 8673D only 19 500 000 26 000 000 2 100 000 2 000 000 2
113. 2 0 GHz Normal Mode 6 dBm to 10 dBm 2 0 to lt 16 0 GHz HP 8673C 3 dBm to 10 dBm 16 0 to 18 6 GHz H2 8678D 7 dBm to 10 dBm 16 0 to 26 0 GHz Bypass Mode 9 dBm to 10 dBm 2 0 to lt 16 0 GHS HP 8673C 6 dBm to 10 dBm 16 0 to 18 6 GHz HP 8673D 8 dBm to 10 dBm 16 0 to 26 0 GHz Remote Programming Absolute Level Accuracy 0 05 6 6 GHz 1 25 dB 10 dBm output level range 1 00 dB 0 dBm output level range 1 50 dB 10 dBm output level range 1 70 dB 20 dBm output level range 2 00 dB 30 dBm output level range 2 00 dB amp 0 1 dB per 10 dB step lt 30 dBm output level range gt 6 6 12 3 GHz 1 50 dB 10 dBm output level range 1 25 dB 0 dBm output level range 1 75 dB 10 dBm output level range 1 95 dB 20 dBm output level range 2 25 dB 30 dBm output level range 2 25 dB amp 0 1 dB per 10 dB step lt 30 dBm output level range 1 8 HD 8673C D Electrica Characteristics RF OUTPUT cont d gt 12 3 18 6 GHz gt 18 6 26 0 GHz Manual Absolute Level Accuracy Remote Programming Output Level Resolution Flatness Output Level Switching Time to be within 1 dB of final level PULSE MODULATION ON OFF Ratio Rise and Fall Times Minimum Leveled RF Pulse Width Pulse Repetition Frequency Minimum Duty Cycle Minimum Pulse Off Time Maximum Peak Power Peak Level Accuracy Table 1 1 Specifications 4 of 7 Performance Limits 1 75
114. 3 12 ADDITIONAL OPERATING INFORMATION _ Signal Generator performance can be optimized by considering the effect of the following controls on the RF output AUTO PEAK ALC PULSE Modulation SWEEP Mode SWEEP mode in a Master Slave configuration CMO oo Operation 3 13 AUTO PEAK Major power and pulse modulation specifications are not warranted unless an AUTO PEAK opera tion has been performed An AUTO PEAK opera tion is automatically performed when the fre quency changes by more than 50 MHz while AUTO PEAK is enabled AUTO PEAK is auto matically enabled when the instrument is turned on or when PULSE mode is selected The front panel AUTO PEAK button toggles the state of the instrument between AUTO PEAK enabled and disabled mode A user initiated AUTO PEAK operation may be performed manually at any time by pressing the AUTO PEAK button twice to dis able and re enable AUTO PEAK The actual peak ing operation occurs when the AUTO PEAK is switched from the disabled to enabled mode Under program control disabling enabling and per forming an AUTO PEAK operation can all be con trolled separately with the KO K1 and K2 com mands See Table 3 7 3 14 ALC Automatic Level Control Output power leveling for the instrument s fre quency range occurs from four sources selected by the operator These sources are a INTERNAL b DIODE c PWR MTR Power Meter d SYS System INTERNAL RF power outpu
115. 4 3 Level Accuracy Test Setup e 4 9 3 3 Output Level Features 3 9 4 4 Low Frequency Pulse Test Setup 4 12 3 4 Frequency Control Features and 4 5 Risetime Overshoot and Ringing LINE Switch 6 wa fh stews 6a ita no reete key 3 10 Measurement 22 cece ence eee 4 13 vi Contents ILLUSTRATIONS cont d HP 8673C D Figure 4 6 Pulse Peak Level Accuracy Measurement 6 65 200k eter Ss tddy osn ex 4 7 High Frequency Pulse Test Setup 4 8 AM Accuracy Test Setup 4 9 External FM Accuracy and Meter Accuracy Test Setup 4 10 Frequency Range and Resolution TORE Setup sorserien e a AiE eee 4 11 Internal Time Base Aging Rate Test Setup ied re a a a AEEA 4 12 Frequency Switching Time Test Setup 4 13 Frequency Switching Waveform 4 14 Frequency Switching Time Measurement Waveform seereis ereda orraa shew an 4 15 Amplitude Recovery Switching WAVGTOTR 59 ST N a Ra EE EAT 4 16 Amplitude Recovery Measurement Wavelorm reiese R RRR e 4 17 Single Sideband Phase Noise Test Setup STN we R AR Na N 0 E 4 18 Harmonics Subharmonics and Multiples Test Setup S 4 19 Non harmonically Related Spurious TORU Setup arrene ecoka sake aoe Dee e eee 4 20 Power Line Related Spurious Signals Test Setup or 6ea ade Sie e ewe En AVAT ee Table l 1 Specifications te 1 2 Supplemental Characteristics 1 3 Recommended Test Equipment
116. 410B C Compatible Trigger Output Service Function Frequency Increment Frequency Decrement Blank Frequency Display Recall Register 1 Sequential Register Recall Outputs Trigger HP 8410B C Compatible End Sweep Negative Z axis Blanking Ground Contact closure to ground or 5 us negative true TTL pulse 5 us negative true TTL pulse General Information Performance Limits Conditions Maximum of 9999 frequency points per sweep Filter amplifier bands NORMAL 0 01 to lt 2 0 GHz 2 0 to lt 3 5 GHz 3 5 to lt 6 0 GHz 6 0 to 18 6 GHz HP 86730 6 0 to lt 16 0 GHz HP 8673D 16 0 to lt 22 0 GHz HP 8673D 22 0 to 26 5 GHz HP 8673D BYPASS 2 0 to 18 6 GHz HP 8673C 2 0 to lt 16 0 GHz HP 8673D 16 0 to 26 5 GHz HP 8673D Resolution and accuracy are identical to RF output fre quency specifications General Information HP 8673C D Table 1 1 Specifications 7 of 7 Electrical Characteristics Performance Limits raes REMOTE OPERATION Output Data Interface Function Codes GENERAL Operating Temperature Range Power Requirements Line Voltage 100 120 220 or 240V Power Dissipation Conducted and Radiated Electromagnetic Interference Net Weight Dimensions Height Width Depth All functions HP IB programmable except LINE switches and HP IB address Frequencies and output level set tings error malfunction messages operational status and learn mode strings
117. 50 ohm load or 6 dB attenuator to the Signal Generators RF OUTPUT connector This reduces unwanted power reflections back into the RF OUTPUT connector thereby preventing a false UNLEVELED annunciator indication Set FREQUENCY to 6 6 GHz and Output Level VERNIER to 2 dBm Press the RF OUTPUT key to OFF Verify that the UNLEVELED and UN LOCKED status annunciators turn on and that the meter indicates lt 10 dBm Press the RF OUTPUT ON OFF key to ON Verify that the status annunciators turn off and that the meter indicates 2 dBm Step the output level down in 10 dB steps from 70 to 90 dB using the RANGE key Then step the output level up in 10 dB steps from 90 to 10 dB Verify that the UNLEVELED annunciator remains off at each step Set Output Level RANGE to 0 dB and sweep the Output Level VERNIER from 10 dBm to 3 dBm Verify thatthe UNLEVELED annunciator remains off at all VERNIER settings Press RCL 0 to set the Signal Generator to a known state Set frequency to 16 1 GHz Repeat step 19 Set FREQ INCR to 10 MHz Then set the output level to the values shown in the following table Tune from the corresponding start frequency to the stop frequency for each output level Verify that the indicated power level on the meter remains HP 8673C D OPERATOR S CHECKS Operation Basic Functional Checks Procedure cont d cont d leveled HP 8673C D HP 8673C D HP 8673C HP 8673
118. 6 668 2 007 778 MHz 2007 777 agea 2 007 779 2 008 889 MHz 2 008 888 eee 2 008 890 2 009 999 MHz 2 009 998 oredr eet 2 010 000 2 090 000 MHz 2 089 999 dae as 2 090 001 2 280 000 MHz 2 279 999 ett Se 2 280 001 2 470 000 MHz 2 469 999 oo a 2 470 001 2 660 000 MHz 2 659 000 E 2 660 001 2 850 000 MHz 2 849 000 ast 2 850 001 3 040 000 MHz 2039 999 a E 3 040 001 3 230 000 MHz 3229 99 3 230 001 3 420 000 MHz 3 419 999 ees 3 420 001 3 610 000 MHz 3 609 999 ee eae 3 610 001 3 800 000 MHz 3 799 999 Z 3 800 001 3 990 000 MHz 3 989 999 3 990 001 4 180 000 MHz 4 179 999 4 180 001 4 370 000 MHz 4 369 999 4 370 001 4 560 000 MHz 4 559 999 4 560 001 4 750 000 MHz 4 749 999 4 750 001 4 940 000 MHz 4 939 999 4 940 001 5 130 000 MHz 5 129 999 5 130 001 5 320 000 MHz 5 319 999 5 320 001 5 510 000 MHz 5 509 999 D 510 001 5 700 000 MHz 5 699 999 5 700 001 5 900 000 MHz 5 899 999 5 900 001 6 100 000 MHz 6 099 999 6 100 001 6 600 000 MHz 5 999 999 6 600 001 Bands 2 and 3 Test 10 GHz 2 kHz Resolution beeen 18 GHz 3 kHz Resolution itera ZT HP 8673D only 25 GHz 4 kHz Resolution V 4 91 Performance Tests HP 8673C D Table 4 4 Performance Test Record 2 of 13 Para Test Ne 4 9 INTERNAL TIME BASE AGING RATE 5x107 day Peterlee Renda w nT pag 4 10 FREQUENCY SWITCHING TIME Frequency Switching 3 0 to 1 9 GHz ree 50 ms 4 0 to 1 9 GHz TEEI nae 50 ms 18 0 to 1 9 GHz 50 ms 6 2 to 2 09 GH
119. 6 GHz In the multiplied bands there is feedthrough from the fundamental and its harmonics These spurious signals are termed subharmonics and are typically at a fixed amplitude with respect to the multiplied frequency For this reason the higher VERNIER settings provide a better signal to spurious ratio The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The following program is used to set the ALC mode of the Signal Generator Valid Modez strings are INTERNAL DIODE POWER METER and SYSTEM 3 87 Operation HP 8673C D Detailed Operating Instructions Internal Automatic Level Control conta Programming 10 SUB Set_alc Err Mode Example 20 IF Mode INTERNAL THEN P_code C1 cont d 30 IF Mode DIODE THEN P_code C2 40 IF Mode POWER METER THEN P_code C3 50 IF Mode SYSTEM THEN P_code C4 60 OUTPUT 719 USING 2A P_code 70 END Error The following message may be displayed when programming the RF output level Messages 24 The programmed RF output level is outside of the Signal Generator s range 3 88 HP 8673C D Description Local Procedure Operation Detailed Operating Instructions Manual Sweep Mode The Signal Generator performs a digital sweep by stepping the RF output frequency in discrete steps from the start frequency to the stop frequency The number of steps that the Signal Generator produces between the start and sto
120. 7 GHz and repeat steps 11 through 13 The signal level should be at least 80 dB below the reference ON OFF Ratio 6 7 GHz pe 80 OBE Connect equipment as shown Figure 4 7 Set the local oscillator to 6 75 GHz and output level to 7 dBm Set the Signal Generator to 6 7 GHz Set RANGE to 0 dBm and the VERNIER to 10 dBm This will result in a 50 MHz IF pulse modulated signal displayed on the oscilloscope Center the waveform on the oscilloscope display Adjust the oscilloscope vertical position and sensitivity controls so that the pulse base line is one division from the bottom graticule line and 5 divisions in peak amplitude See Figure 4 5 Measure rise time and overshoot Record results in the following table Rise Time at 6 7 GHz ee C 4 nS Overshoot and Ringing at 6 7 GHz Lnn Li Repeat steps 7 8 and 9 to measure peak level accuracy Repeat measurement for risetime and overshoot at 12 and 18 GHz keeping the local oscillator frequency 50 MHz above the Signal Generator frequency For the HP 8673D repeat also at 19 GHz 4 14 HP 8673C D Performance Tests ABBREVIATED PERFORMANCE TESTS PULSE MODULATION TEST contd Procedure cont d HP 8673C D SYNTHESIZED SIGNAL GENERATOR OSCILLOSCOPE EXTERNAL EXTERNAL 50Q 2 TRIG OUT TRIG IN VERTICAL iNPUTS 10 dB ATTENUATOR BNC 26 GHz TEE 20 dB 20 dB POWER 10 dB PREAMPLIFIER 10 dB AMPLIFIER ATTENUATOR ATTENUATOR ae DET T LOCAL OSCILLATOR
121. 738C D 3 20 REMOTE OPERATION AUXILIARY CONTROL 3 21 AUX Input Lines A limited number of instrument functions can be controlled through the rear panel AUX connector These functions are listed in Table 3 2 below The input lines are TTL compatible and negative edge sensitive They require a minimum of 5 us between negative edges Input signals can be gen erated by clean TTL drivers or by mechanical switches that require debouncing The Signal Generator has a built in debouncing circuit that should be enabled or bypassed depending upon which type of driver is used The Signal Generator is shipped from the factory configured for electrically clean control signals i e the internal debouncing circuit is bypassed Refer to Figure 2 5 in Section II Installation for Operation og HP cren the procedure for enabling or bypassing the debouncing circuit NOTE Section IT Installation also shows the pinout configuration of the AUX con nector as well as information for a recommended mating connector 3 22 AUX Output Lines The AUX connector also has a ground line and three TTL compatible output lines The output lines are normally held at the high TTL level The End of Sweep line produces one 5 us low going pulse at the end of each sweep The Trigger line produces one 5 us low going pulse when the Signal Generator has madea large frequency change that may cause loss of phase lock in an instrument tracking the Signal G
122. 86738C D Operation OPERATOR S CHECKS HP IB Functional Checks contr d Clear Message Note This check determines if the Signal Generator properly responds to the Clear message This check assumes that the Signal Generator is in the remote mode Description Series 200 300 HP 85F BASIC Send a Data message that turns OUTPUT 719 Ko OUTPUT 719 K0 AUTO PEAK off Operator s Check that the Signal Generator s AUTO PEAK key indicator is off Response Send the Clear message turning the CLEAR 719 CLEAR 719 Signal Generator s AUTO PEAK function on Operator s Check that the Signal Generator s AUTO PEAK key indicator is on Response Abort Message Note This check determines if the Signal Generator becomes unaddressed when it receives the Abort message This check assumes that the Signal Generator is in the remote mode Description Series 200 300 HP 85F BASIC a Address the Signal Generator to listen OUTPUT 719 OUTPUT 719 Operator s Check that the Signal Generator s LSN and RMT annunciators are on Response Send the Abort message unaddress ABORT 7 ABORTIO 7 ing the Signal Generator from listen ing Operator s Check that the Signal Generator s LSN annunciator is off but the RMT annunciator Response is on Status Byte Message Note This check determines if the Signal Generator sends the Status Byte message Before beginning this check turn the Signal Generator s LINE sw
123. 8673C D PERFORMANCE TESTS 4 14 POWER LINE RELATED SPURIOUS SIGNALS TESTS Specification f Electrical Performance Characteristiss Characteristics ieai ee Conditions SPECTRAL PURITY Power line related and fan 0 05 6 6 GHz rotation related within 50 dBe lt 300 Hz offset from carrier 5 Hz below line frequencies 60 dBc 300 Hz to 1 kHz offset from carrier and multiples thereof 65 dBe gt 1 kHz offset from carrier 6 6 12 3 GHz 44 dBe lt 300 Hz offset from carrier 54 dBe 300 Hz to 1 kHz offset from carrier 59 dBe gt 1 kHz offset from carrier 12 3 18 6 GHz 40 dBe lt 300 Hz offset from carrier 50 dBe 300 Hz to 1 kHz offset from carrier 55 dBe gt 1 kHz offset from carrier HP 8673D only 18 6 26 0 GHz 38 dBe lt 300 Hz offset from carrier 48 dBc 300 Hz to 1 kHz offset from carrier 53 dBe gt 1 kHz offset from carrier Description The RF output of the Signal Generator is mixed with a local oscillator to obtain a 20 kHz IF signal The line related sidebands are observed on a spectrum analyzer NOTE The Signal Generator and local oscillator are isolated from vibration on a two inch thick foam pad The Signal Generator must be operated froma separate power line source 52 to 58 Hz in order to differentiate its spurious signals from other line related spurious signals Equipment Local Ose ater iss aucadeweadan ceneokeroaaiass HP 8340A Spectrum Analyzer
124. 9 999 5 699 999 5 899 999 6 099 999 5 999 999 2 090 001 2 280 001 2 470 001 2 660 001 2 850 001 3 040 001 3 230 001 3 420 001 3 610 001 3 800 001 3 990 001 4 180 001 4 370 001 4 560 001 4 750 001 4 940 001 5 180 001 5 320 001 5 510 001 5 700 001 5 900 001 6 100 001 6 600 001 HP 8673C D Performance Tests PERFORMANCE TESTS FREQUENCY RANGE AND RESOLUTION TEST coni d Procedure cont d NOTE Fast tuning of frequency may cause the NOT LOCKED annunciator to flash on momentarily This ts normal and does not indicate a malfunction Bands 2 and 3 Test if 10 11 12 Tune the Signal Generator to 10 000 000 MHz and set the frequency increment FREQ INCR to 1 kHz Tune the frequency down one increment and verify that the Signal Generator frequency display changes to 9 999 998 MHz and the frequency counter reading agrees within 1 count Tune the frequency up two increments and verify that the Signal Generator frequency display changes to 10 000 002 MHz Verify also that the frequency counter reading agrees within 1 count 10 GHz frequency resolution 2 kHz SS V Tune the Signal Generator to 18 599 997 MHz and set the frequency increment FREQ INCR to 1 kHz Tune the frequency down one increment and verify that the Signal Generator frequency display indicates 18 599 994 MHz and the frequency counter reading agrees within 1 count Tune the frequency up two increments a
125. ALC 1 Pressthe RANGE up or down key until the desired RANGE appears in the RANGE dB display Holding the key down will continue stepping the RANGE until the key is released The RANGE setting represents the maximum level available using that range The VERNIER control will allow setting output levels from 10 dB below to 3 dB above the RANGE There is a slight overlap of output level settings due to the 13 dB range of the VERNIER control For best results the VERNIER setting should be within the range of 10 to 0 dBm VERNIER settings from 0 to 3 dBm are available for observing a continuous range up to 3 dB above the RANGE setting without changing the RANGE setting 2 Adjust the VERNIER control until the sum of the RANGE and the level meter reading equal the desired RF output level The VERNIER can be used to vary the output level continuously about the set level or the RANGE up or down key can be used to step the output level in 10 dB steps If the ALC UNLEVELED annunciator lights for high output level settings the level meter will indicate maximum available output power This should only occur when output levels above the specified maximum leveled power are set For example ifthe RF output level is set to 13 dBm and the level meter reads 4 dBm with the ALC UNLEVELED annunciator lighted only 9 dBm of output power is available at that frequency The Signal Generator accepts any RF output level between 101 9 and 13 dBm RF
126. ALC INTERNAL ALC DIODE ALC PWR MTR ALC SYS Mode or SHC2 dB AF dB FREQ INCREMENT Down DWELL FM DEVIATION OFF FM DEVIATION OFF FM DEVIATION 03 MHz FM DEVIATION 1 MHz FM DEVIATION 3 MHz FM DEVIATION 1 MHz FM DEVIATION 3 MHz FM DEVIATION 10 MHz START Sweep Frequency STOP Sweep Frequency FREQ INCR FREQ INCR OFFSET or SHFB OFFSET or SHDF FREQUENCY AF OFFSET OFFSET FREQ INCR GHz Hz Increment Frequency Sweep Instrument Preset kHz AUTO PEAK OFF AUTO PEAK ON AUTO PEAK without extra settling time Program x Parameter Level RANGE and VERNIER Front Panel Learn Mode Special Function Learn Mode MESSAGE milliseconds MULT or SHFA MULT MHz Marker s OFF Marker 1 Marker 2 Marker 3 Marker 4 Marker 5 TUNE Knob OFF TUNE Knob ON Output Active Parameter Output Couple Output Lock Frequency Front Panel Learn Mode Output Request Mask Output Status Power Level RANGE and VERNIER PULSE OFF PULSE OFF PULSE NORM PULSE COMP RANGE Recall RCL Alternate Instrument Preset RANGE Down 10 dB RE OFF RF ON Recall RCL RQS Mask Reset Sweep i RANGE Up 10 dB RF OFF RF ON Slave Down STEP MANUAL Sweep STEP Shift Steps suffix Store STO Slave Up Service Function Test Interface Execute Trigger HD 8673C D Operation Table 3 6 HP IB Program Codes 2 of 2 Program Program Parameter Code Parameter Meter LVL XFREQ Meter AM Marker s OFF Meter FM Marke
127. ANGE and VERNIER controls The following message may be displayed when programming the RF output level 24 The programmed RF output VERNIER RANGE or both is outside the Signal Generator s range HP 8673C D Description Local Procedure Remote Procedure Operation Detailed Operating Instructions Vernier Output Level The RF output level of the Signal Generator is set using the RANGE and VERNIER controls The RANGE controls change the RF output level in 10 dB steps and the VERNIER changes the RF output level continuously over a 13 dB range The sum of the output level RANGE and VERNIER is the actual RF output level In local mode the output level meter displays the VERNIER setting In remote mode the output level meter displays the remote setting When going from local to remote mode the RF output level should not change by more than 0 1 dB When changing from remote to local mode the RF output level will return to the front panel setting of the VERNIER which may change the RF output level by as much as 13 dB The RANGE setting will not change for either transition When setting RF output levels above the specified maximum power an ALC UNLEVELED condition may occur due to insufficient available power When this occurs the output level meter will indicate the maximum available power Increasing the VERNIER setting will not change the displayed level on the output level meter To set the RF output level using internal
128. Accuracy Test 4 73 i AM Bandwidth Ta ga R NA TRR aa a a 4 76 Section IV AM Accuracy Tests e 4 78 PERFORMANCE TESTS Incidental EM aaa Ra NR caves ATR NO REE 09 4 81 TntroducHon ssh his wo is nha de SOS teehee 4 1 FM Frequency Response 0 202 cece eee 4 84 Abbreviated Performance Test 4 1 External FM Accuracy and Meter Accuracy 4 86 Calibration Cycle cuts esbace caverns ase 4 1 Incidental AM eee 0 80 ILLUSTRATIONS Figure Page Figure Page 1 1 HP 8678C D Accessories Supplied and 3 5 Sweep Features and LOCAL Key 3 12 Options 908 and 913 0 cece eee 1 2 3 6 Modulation Features 0 00 eee eee 3 14 1 2 Special Interconnect Cable 1 19 3 7 Rear Panel Features 0 ccc cece ees 3 15 2 1 Line Voltage and Fuse Selection 2 2 S Funct i Check SER dessein Set 9 Power Cable and Maine Plus 3 9 FM Functional Check Setup IEEE been 3 21 3 10 Pulse Modulation Functional l Part Numbers a annnoasonsnosasnsos 2 2 Check Setup 3 99 2 3 HP IB Address Switch Factory Settings 2 3 Sii Status Byte Eora Bai E Pee te 3 4 2 4 Hewlett Packard Interface Bus Gg ee E Saal aca 25 AUX Interface Connector E g7 Y Frequency Range and Resolution Test Setup csuri tet sane cess ater E iaa 4 3 3 1 Front Panel Features 0 4 32 4 2 Output Level and Flatness Test Setup 4 5 3 2 Displays and Status Annunciators 3 8
129. B 2 50 dB 2 85 dB 3 30 dB 2 45 dB 2 45 dB 2 70 dB 3 05 dB 3 60 dB HP 8673C D Performance Tests Table 4 4 Performance Test Record 7 of 13 No Min Actual Max 4 16 ABSOLUTE LEVEL ACCURACY cont d Low Level Accuracy 50 MHz 30 dBm 32 75 dBm 27 25 dBm 40 dBm 42 85 dBm 37 15 dBm 50 dBm 52 95 dBm 47 05 dBm 60 dBm 63 05 dBm 56 95 dBm 70 dBm 73 15 dBm 66 85 dBm 80 dBm 83 25 dBm 76 75 dBm 90 dBm 93 35 dBm 86 65 dBm 4 0 GHz 30 dBm 32 75 dBm 27 25 dBm 40 dBm 42 85 dBm 37 15 dBm 50 dBm i 52 95dBm 47 05 dBm 60 dBm 3 05 dBm 56 95 dBm 70 dBm 73 15 dBm 66 85 dBm 80 dBm 83 25 dBm 76 75 dBm 90 dBm 93 35 dBm 86 65 dBm 10 GHz i 80 dBm 33 00 dBm 27 00 dBm 40 dBm 43 10 dBm 36 90 dBm 50 dBm 53 20 dBm 46 80 dBm 60 dBm 3 30 dBm 56 70 dBm 1 70 dBm 73 40 dBm 66 60 dBm 80 dBm 83 50 dBm 76 50 dBm 90 dBm 93 60 dBm 86 40 dBm 14 GHz 30 dBm 34 45 dBm 26 55 dBm 40 dBm 43 65 dBm 36 35 dBm 50 dBm 53 85 dBm 46 15 dBm 60 dBm 64 05 dBm 55 95 dBm 70 dBm 74 25 dBm 65 75 dBm 80 dBm 84 45 dBm 75 55 dBm 90 dBm 95 65 dBm 83 35 dBm HP 8673D only 20 GHz 30 dBm 34 05 dBm 25 95 dBm 40 dBm 44 25 dBm 35 75 dBm 50 dBm 54 45 dBm 45 55 dBm 60 dBm 64 65 dBm 56 7
130. C Operator s Check P Performance Tests A Adjustments T Troubleshooting i i x l c The HP 8903B is recommended for the combined use as an analyzer and audio source A separate audio analyzer and an audio source can be used if critical specifications are met 2 RHG Electronics Laboratory Inc 161 East Industry Court Deer Park NY 11729 Tel 516 242 1100 TWX 510 227 6083 3 California Instruments 5150 Convoy Street San Diego CA 92111 Tel 714 279 8620 SPECIAL INTERCONNECT CABLE Figure 1 2 Special interconnect Cable 1 19 General Information HP 8673C D Table 1 4 Abbreviated Performance Test Recommended Test Equipment 1 of 2 m R Recommended instrument Critical Specifications Attenuator Fixed 6 dB Range de to 26 GHz HP 8493C Accuracy 0 6 dB Option 006 SWR lt 1 6 Attenuator Fixed 10 dB Range de to 12 4 GHz HP 8491A two needed Accuracy 0 6 dB Option 010 SWR lt 1 3 Attenuator Fixed 10 dB Range de to 26 GHz HP 8493C Accuracy 1 0 dB Option 010 SWR lt 1 6 Attenuator Fixed 20 dB Range de to 26 GHz HP 8493C Accuracy 1 0 dB Option 020 SWR lt 1 6 Audio Analyzer Frequency Range 20 Hz to 100 kHz HP 8908B Accuracy 4 of full scale Audio Source Frequency Range 20 Hz to 100 kHz HP 8903B Output Level 1 mV to 6V open circuit Flatness 2 5 Cable Semi Rigid 8 length SMA m m Locally Fabricated Digital Voltmeter Resolution 1 mV HP 3456A Range 212
131. C D WEIGHT RQS Bit Request Service Entry Error Change in Sweep Parame ters l Condition BIT WEIGHT Operation Front Front i Panel Panel Entry Key Complete Pressed Change in Ex tended Status Source Settled 1 te ALC Un leveled Power Not Fail ure On Condition always Phase Locked FM Over modulated Self Test i Failed External Ref always Figure 3 11 Status Byte Information bit is stored in a buffer and is read the next time the Signal Generator receives the Serial Poll Ena ble SPE bus command When addressed to talk following SPE the Signal Generator sends the Status Byte message After the Status Byte message has been sent it will be cleared if the Serial Poll Disable SPD bus command is received if the Abort message is received or if the Signal Generator is unaddressed to talk However bits stored in the buffer waiting to be read are not cleared Regardless of whether or not the Status Byte message has been sent the Status Byte and any Require Service message pending will be cleared if a Clear Status CS pro gram code is received or the Output Status func tion is executed NOTE The Signal Generator must receive a universal untalk command after send ing the Status Byte message Most sys tem controllers send this automatically However if a universal untalk command is not sent the SRQ bus line may not be
132. CT 190 200 OUTPUT 719 USING 2A OK Requests current frequency 210 ENTER 719 USING K Set_freq Frequency in Hz 220 Set_freg INT Set_freq 1000 1000 Convert to MHz 230 240 IF ABS Set_freq Frequency gt 001 AND Err 0 THEN 250 DISP WARNING Requested frequency rounded to Set_freq 260 END IF 270 SUBEND End of subroutine 3 74 HP 8673C D Programming Example cont d Error Messages Operation Detailed Operating Instructions Frequency CW conta To prevent roundoff errors from occurring the following subprogram may be used to adjust a frequency so that it is always within 1 or 2 kHz of the desired frequency Frequencies below 18 6 GHz will be within 1 kHz of the desired frequency and frequen cies between 18 6 and 26 GHz will be within 2 kHz of the desired frequency 300 SUB Round_off Err Expected Expected frequency in MHz 310 Err 0 Initialize Err 320 Band 5 330 IF Expected lt 26500 001 THEN Band 4 340 IF Expected lt 18600 001 THEN Band 3 350 IF Expected lt 12300 001 THEN Band 2 360 IF Expected lt 6600 001 THEN Band 1 3 0 380 Baseband INT Expected 1000 Band 1000 Rounded fundamental 390 Round_down Baseband Band 400 IF Round_down lt gt Expected THEN Requires rounding 410 Round_up Baseband 001 Band 420 IF ABS Round_down Expstled LED Expected THEN 430 Expected Round_down Minimum error is round down 440 ELSE 450 Expected Round_up Minimum error is round up
133. Carrier Level 0 dBm Typical HP 86730 0 AM distortion versus modulation rate and depth 1 15 General Information HP 86738C D Table 1 3 Recommended Test Equipment 1 of 4 Critical Specifications ooo w AC Voltmeter Range 1 mV to 10V HP 4008 P A Accuracy 1 5 of full scale 1 5 of reading Frequency Response 3 kHz to 3 MHz Attenuator Range de to 1 GHz HP 8491A Fixed 3 dB Accuracy 0 5 dB Option 003 SWR lt 1 3 Attenuator Range de to 26 GHz HP 8493C Fixed 6 dB Accuracy 0 6 dB Option 006 SWR lt 1 6 Attenuator Range de to 12 4 GHz HP 8491A Fixed 10 dB Accuracy 0 6 dB Option 010 SWR lt 1 8 Attenuator Range de to 26 GHz HP 8493C Fixed 20 dB Accuracy 1 0 dB Option 020 SWR lt 1 6 Attenuator Range de to 26 GHz HP 8495D 10 dB Step Accuracy 7 Option 004 SWR lt 2 2 j Audio Analyzer Frequency Range 20 Hz to 100 kHz j HP 8903B P Accuracy 4 of full scale Audio Source Frequency Range 20 Hz to 100 kHz HP 8903B P Output Level 1 mV to 6V open circuit Flatness 2 5 Cable Special Special see Figure 1 2 Locally Fabricated A Interconnect Controller HP IB HP IB compatibility as defined by IEEE HP 85A 82987A Standard 488 1978 and the identical ANSI 00085 15001 Standard MC1 1 SH1 AH1 T2 TEO L2 00085 15002 LEO SRO RLO PPO DCO DTO and C1 2 3 00085 15003 4 5 00085 15004 00085 15005 or Autom
134. Continue entering the correct digits until the frequency displayed in the FREQUENCY MHz display is correct 3 Press the appropriate units key You may enter the frequency in GHz MHz or kHz Once the units key is pressed the displayed frequency will be adjusted to display MHz and the output frequency will be set If asweep modeis active when CW frequency is entered the actual frequency displayed after pressing the units key will usually not be the entered frequency The FRE QUENCY MHz display is used to display sweep information during sweep mode so the new CW frequency will not be displayed Setting the CW frequency during a sweep changes the sweep center frequency to the value entered The sweep will continue about the new CW center frequency Tuning the frequency will also move the sweep center frequency when in sweep mode To check the current CW center frequency during sweep press and hold the FREQUENCY key The FREQUENCY MHz display will display the CW frequency as long as the key is held The Signal Generator will return to the CW frequency when the sweep mode is turned off HP 86738C D Remote Procedure Example Operation Detailed Operating Instructions Frequency CW conta The Signal Generator accepts any frequency within its specified frequency range Above 6 6 GHz the programmed frequency may be rounded by the Signal Generator to be compatible with the 2 3 or 4 kHz resolution at the programmed frequency see co
135. D HP 8673C D HP 8673C D HP 8673C HP 8673D HP 8673C D HP 86738C D HP 8673C HP 8673D HP 8673C D HP 8673C D HP 8673C HP 8673D Sweep Check The FREQUENCY MHz display is used to check the ability of the Signal Generator to SWEEP Range STANDARD ee oe n OPTION 001 Vernier OPTION 004 Vernier OPTION 005 Vernier 0 05 GHz 2 00 GHz 16 00 GHz 16 00 GHz 0 05 GHz 2 00 GHz 16 00 GHz 16 006 GHz 0 05 GHz 2 00 GHz 16 00 GHz 16 00 GHz 26 00 GHz 1 99 GHz 15 99 GHz 18 60 GHz lt 1 99 GHz 15 99 GHz 18 60 GHz 26 00 GHz 1 99 GHz 15 99 GHz 18 60 GHz 26 00 GHz 1 99 GHz 15 99 GHz 18 60 GHz 26 00 GHz constant and stable and that the UNLEVELED annunciator remains off This ensures that the instrument can generate specified output power and remain 3 19 Operation HP 8673C D OPERATOR S CHECKS Basic Functional Checks cont d Procedure 24 cont d 25 26 27 28 29 30 ol Press RCL 0 to set the instrument to a known state and press BYPASS NORMAL to enable BYPASS mode Then press the AUTO sweep key Verify that the FRE QUENCY MHz display now shows a start frequency of 2000 000 MHz and a stop frequency of 4000 000 MHz The AUTO key indicator should flash once each timea new sweep begins Press SWEEP OFF Verify that the FREQUENCY MHz display returns to 3000 000 MHz Press the MANUAL sweep key T
136. DIODE SYS Key Normal operation Diode Selects external mode for leveling power using an external diode detector The output of the diode is connected to the Signal Generator s EXT ALC iN connector Shifted function SYS Selects the system leveling mode RF output power is leveled externally using a feedback voltage proportional to the system output power in volts per dB A system is the Signal Generator with an external amplifier multiplier etc The reference voltage must be 0 VDC at 0 dBm system output and change 30 mV per dB This voltage is connected to the EXT ALC IN connector When SYS is selected both the EXTERNAL and DIODE keys will light 5 PWR MTR Key Selects external leveling mode for leveling power using an external power meter The recorder output of the power meter is connected to the EXT ALC IN connector 6 Mechanical Meter Zera Sets meter suspension so that the meter indicates zero when power is removed from the Signal Generator and the Signal Generator is in its normal operating position Ge OUTPUT LEVEL RANGE Keys LS and lt p Selects the RF output level range in 10 dB steps from 90 to 10 dB The selected range is displayed in the RANGE dB display Le QUTPUT LEVEL VERNIER Adjusts the RF output level over the range of 10 to 3 dBm relative to the LVL scale as read on the meter CAL Control Adjusts the power level at the load when using a Giode detector or power meter for external levelin
137. ED bit will be set by the instrument preset before the frequency change is complete Ifthe bitis being checked before proceeding the program will continue before the frequency change has settled Status bits are set asynchronously whenever the corresponding condition occurs Ifa condition occurs between the time the output extended status program code is received and the time both status bytes are read the status byte will reflect the changed condition by setting the appropriate bit Note that once a bit is set only a clear status or reading the extended status can clear it When the ENTRY ERROR bit is enabled to cause a service request the message must be cleared after the service request Failure to clear the message will result in additional service requests generated with each program string To clear the message output the program code MG and then read the message Once the message is read or the MESSAGE key on the front panel is pressed the message will be cleared The status byte and the extended status byte are both binary values When entering the status byte and extended status byte into the controller use a formatted statement to input the values as binary If a formatted statement is not used the controller may recognize a value of twelve as a carriage return and terminate the entry This can occur when the SOURCE SETTLED BIT and the CHANGE IN EXTENDED STATUS bits are the only bits set in the status byte In addition the con
138. ES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY ASSISTANCE Product maintenance agreements and other customer assistance agreements are available for Hewlett Packard products For any assistance contact your nearest Hewlett Packard Sales and Service Office Addresses are provided at the back of this manual iil iv HP 8673 B C D E M Hersteillerbescheinigung Hiermit wird bescheinigt dass dieses Gerat Sys tem in Ubereinstimmung mit den Bestimmungen von Postverfiigung 1046 84 funkenst rt ist Der Deutschen Bundespost wurde das Inverkehr bringen dieses Gerates Systems angezeigt und die Berechtigung zur Uberprifung der Serie auf Ein haltung der Bestimmungen eingeraumt Zusatzinformation fir Mess und Testgerate Werden Mess und Testgerate mit ungeschirmten Kabeln und oder in offenen Messaufbauten ver wendet so ist vom Betreiber sicherzustellen dass die Funk Entst rbestimmungen unter Betriebs bedingungen an seiner Grundstiicksgrenze ein gehalten werden Manufacturers Declaration This is to certify that this product meets the radio frequency interference requirements of Directive FETZ 1046 1984 The German Bundespost has been notified that this equipment was put into circula tion and has been granted the right to check the product type for compliance with these require ments Note If test and measurement equipment is oper ated with unshielded cables and or used for meas urements o
139. EVEL AND FLATNESS TESTS cont d Procedure contd 4 8 Frequency Range 0 05 2 0 GHz 0 05 6 6 GHz 0 05 12 3 GHz 0 05 18 6 GHz HP 8673D only 0 05 2 0 GHz Power Variation Maximum Minimum Total Variation Maximum Minimum Total Variation Maximum Minimum Total Variation Maximum Minimum Total Variation Maximum Minimum Total Variation HP 8673C D HP 8673C D Performance Tests ABBREVIATED PERFORMANCE TESTS LEVEL ACCURACY TESTS Description This test checks level accuracy of the RF output signal The first test uses a power meter to verify that power levels between 0 dBm and 20 dBm are within specification Power levels of 30 dBm and below are checked using a spectrum analyzer The output level of the Signal Generator is adjusted to 20 dBm using the power meter The Signal Gener rator output is then mixed with a local oscillator to produce an IF frequency The IF frequency is displayed on the spectrum analyzer A reference level corresponding to the 20 dBm output is set on the spectrum analyzer and each 10 dB decrease in range is checked for a 10 dB decrease on the spectrum analyzer display Equipment Power Meter 225d ucscapacsngetideccawic HP 436A Power Sensor ica dsaiaiaeerGires tawny HP 8485A Local Oscillator bia ved adie nesgrs HP 8340A Mizer eerie a nee EA haere knees RHG DMS1 26 Spectrum Analyzer 0 0 0 cece ee HP 8566B 40 dB Amplifier 3 0 cud cb
140. FREQUENCY MHz display should show 12 34 and should be left justified 4 Press the GHz units key to finish the sequence The FREQUENCY MHz display should display the entered frequency in MHz and should also be right justified when the units key is pressed The frequency could also have been entered as 12340 MHz or 12340000 kHz The only difference is the placement of the decimal point and the units terminator Pressing the MER key and then MKR OFF will deactivate all of the markers Remote The programming string for setting a marker is composed of a marker identifier the frequency and a units terminator The sweep marker frequency can be programmed in units of GHz MHz kHz or Hz To program marker 3 to 12 34 GHz the possible program strings are HP 8678C D Operation Detailed Operating Instructions Marker Frequency Sweep conta Example M312 34G2 or M312340MZ or M312340000KZ or M312340000000HZ contd The alpha non numeric characters can be sent as upper or lower case or even mixed upper and lower case Program Marker Activation Codes Setting Sweep Marker Deactivation Codes Program Description Program TE All markers off Activate marker 1 Activate marker 2 Activate marker 3 Activate marker 4 Sweep Marker Frequency Activate marker 5 All markers off Activate marker 1 Activate marker 2 Activate marker 3 Activate marker 4 Activate marker 5 Selected Marker Deactivation
141. GE Key Lights to indicate entry errors and flashes to indicate hardware malfunctions A two digit code appears in the FREQUENCY MHz display when this key is pressed Refer to the pull out card or the Messages Detailed Operating Instruction for an explanation of the codes G FREQUENCY MHz Display Normally indicates output frequency Message codes and previously set values for FREQ INCR SWEEP FREQ and SWEEP RATE func tions are displayed for as long as their respective keys are pressed HP IB STATUS Annunciators Indicate the status of the Signai Generator when it is operating via the HP IB RMT lights when the Signali Generator is in remote mode LSN lights when the Signal Generator is addressed to listen TLK lights when the Signal Generator is addressed to talk SHU lights when the Signal Generator is issuing the Require Service message Figure 3 2 Displays and Status Annunciators HP 8673C D Operation i RF OUTPUT Connector 50 ohm APC 3 5 male connector supplies RF output over the entire frequency range of 0 01 to 26 5 GHz B RF OUTPUT ON OFF Key Completely turns off the RF output when set to OFF Setting the RF output to OFF causes the NOT LOCKED and ALC UNLEVELED status annunciators to light When the RF OUTPUT is set to ON the Signal Generator returns to normal operation INTERNAL Key Selects internal circuitry for leveling the output power at the front panel RF OUTPUT connector
142. GHz 6 6 12 3 GHz 12 38 18 6 GHz HP 8673D only 18 6 26 0 GHz Table 4 2 High Level Accuracy Test Record 2 00 dB 2 00 dB 2 25 dB 2 50 dB 3 00 dB 1 75 dB 1 75 dB 2 00 dB 2 25 dB 2 75 dB 1 75 dB 1 75 dB 2 00 dB 2 25 dB 2 75 dB 2 25 dB 2 25 dB 2 50 dB 2 85 dB 3 30 dB 2 45 dB 2 45 dB 2 70 dB 3 05 dB 3 60 dB Performance Tests 2 00 dB 2 00 dB 2 25 dB 2 50 dB 3 00 dB 1 75 dB 1 75 dB 2 00 dB 2 25 dB 2 75 dB 1 75 dB 1 75 dB 2 00 dB 2 25 dB 2 75 dB 2 25 dB 2 25 dB 2 50 dB 2 85 dB 3 30 dB 2 45 dB 2 45 dB 2 70 dB 3 05 dB 3 60 dB Low Level Accuracy Test 20 Tune the Signal Generator to 50 MHz 21 Set the OUTPUT LEVEL RANGE to 20 dB Adjust the VERNIER for a front panel meter indication of 0 dBm 4 55 Performan HP 8673C D PERFORMANCE TESTS ABSOLUTE LEVEL ACCURACY TESTS contd Procedure 22 cont d 24 20 26 27 28 29 30 ol 32 23 Peak the Signal Generator with the AUTO PEAK key Adjust the VERNIER for a power meter reading of 20 0 dBm 0 1 dB Disconnect the power meter and connect the Signal Generator to the attenuator and mixer as shown in Figure 4 22 NOTE Connect the mixer directly to the local oscillator to avoid any power loss Tune the local oscillator to a frequency 100 kHz 1 kHz hig
143. GOTO 220 Wait for source to settle 240 250 IF Expected gt 0 THEN Check for unleveled 260 OUTPUT 719 USING 2A 0S T Get extended status byte 270 ENTER 719 USING B B V Extended 280 IF BIT Extended 6 THEN 290 Err 1 300 DISP WARNING The Signal Generator RF output is not leveled 310 END IF 320 END IF 330 340 SUBEND The following message may be displayed when setting the RF output level For a more complete description of the messages see the MESSAGES detailed operating instruc tions 24 The programmed RF output level is not within the range of the Signal Generator 3 121 Operation HP 86738C D Detailed Operating Instructions Description Local Procedure Remote Procedure Example 3 122 Recall and Store Registers The Signal Generator has nine instrument state storage registers These registers allow the complete instrument state to be saved in non volatile memory A subsequent recall of the stored register will set the Signal Generator to the state that was saved All front panel settings including sweep and modulation are stored when one of the nine registers is used for instrument state storage Powering down the instrument will not destroy the setting of the nine state registers The registers may be cleared to the preset state with a special key sequence see comments Register 0 is the instrument preset register Recalling this register will set the instrument to a know
144. Hz 300 kHz or 3 MHz Full scale indication read on the 0 to 1 scale is 100 kHz 1 MHz or 10 MHz A 1 volt peak signal applied to the FM IN connector develops full scale modulation G Status Annunciators Display the internal conditions of the Signal Generator OFFSET lights when a frequency offset other than zero is entered The displayed frequency is higher OFFSET or jower OFFSET than the actual output frequency MULTIPLIER lights when a frequency multiplier greater than one is entered The displayed fre quency is the output frequency times the multiplier UNLEVELED lights when RF OUTPUT is turned off more power is requested than is available no sig nal is applied to EXT ALC IN when PWR MTR DIODE or SYS is selected no signal is applied to PULSE IN when NORM pulse mode js selected over modulation occurs in AM mode or pulse width is fess than 100 ns FM OVERMOR tights when the signal applied to the FM IN connector exceeds 1 volt peak or when the modulation index exceeds 5 2 0 to 6 6 GHz 10 6 6 upper LINE switch is in the STBY position OVEN COLD lights when the reference oscillator oven is not up to nominal operating temperature UNLOCKED lights when one or more of the inter nal phase lock loops is unlocked the RF OUTPUT is OFF or the INT EXT switch is in the EXT position with no external reference connected EXT REF lights when the rear panel INT EXT switch is in the EXT position MESSA
145. IDENTAL AM 1 0 GHz 2 0 GHz 6 7 GHz 12 4 GHz HP 8673D only 18 7 GHz 4 103 4 104
146. ITH P O TWISTED PAIR WITH 6 REN DIOS DIO7 DIO 6 DIO5 SHIELD CONNECT TO ATN EARTH k g s SO METRIC ___ THREAD M3 9 x 0 6 24 PIN MICRO R1BBON SERIES 57 CONNECTOR Logic Levels The Hewlett Packard Interface Bus Logic Levels are TTL compatible i e the true 1 state is 0 0 Vde to 0 4 Vde and the false 0 state is 2 5 Vde to 5 0 Vdo Programming and Output Data Format Refer to Section IHH Operation Mating Connector HP 1251 0293 Amphenol 57 30240 Mating Cables Available HP 10833A 1 metre 3 8 ft HP 10833B 2 metres 6 6 ft HP 10833C 4 metres 13 2 ft HP 10833D 0 5 metres 1 6 ft Cabling Restrictions 1 A Hewlett Packard Interface Bus system may contain no more than 2 metres 6 ft of connecting cable per instrument 2 The maximum accumulative length of connecting cable for any Hewlett Packard Interface Bus system is 20 0 metres 65 6 ft A3W18 HP IB Adapter HP part number 5060 9462 Figure 2 4 Hewlett Packard Interface Bus Connection HP 8673C D Installation NC STOP SWEEP NC SERVICE NO DISPLAY TRIGGER SINGLE SWEEP GROUND FREQ INCREMENT DOWN END OF SWEEP FREQ INCREMENT UP TRIGGER OUTPUT RECALL NEXT NEGATIVE BLANKING RECALL 1 14 Pin Micro Ribbon 57 Series Connector Logic Levels The rear panel AUX connector logic levels are TTL compatible 5 microseconds negative true TTL pulse or a contact closure to ground internal Jumper Selection If the sig
147. L mode and output power to be within 3 dB of set level SPECTRAL PURITY Single sideband Phase Noise 0 05 6 6 GHz lt 58 dBe 1 Hz bandwidth CW mode 10 Hz offset from carrier lt 70 dBe 100 Hz offset from carrier lt 78 dBc 1 kHz offset from carrier lt 86 dBc 10 kHz offset from carrier lt 110 dBe 100 kHz offset from carrier gt 6 6 12 3 GHz lt 52 dBe 10 Hz offset from carrier lt 64 dBe 100 Hz offset from carrier lt 72 dBe 1 kHz offset from carrier lt 80 dBc 10 kHz offset from carrier lt 104 dBe 100 kHz offset from carrier gt 12 3 18 6 GHz lt 48 dBe 10 Hz offset from carrier lt 60 dBe 100 Hz offset from carrier lt 68 dBc 1 kHz offset from carrier lt 76 dBe 10 kHz offset from carrier lt 100 dBe 100 kHz offset from carrier For temperature specifications refer to Operating Temperature Range near the end of this table 1 6 HP 8673C D Electrical Characteristics SPECTRAL PURITY cont d gt 18 6 26 0 GHz HP 8673D Harmonics up to 26 GHz normal mode power levels lt 3 dBm Subharmonics Spurious Nonharmonically Related Power line related and fan rotation related within 5 Hz below line frequencies and multiples thereof 0 05 6 6 GHz gt 6 6 12 3 GHz gt 12 3 18 6 GHz gt 18 6 26 0 GHz HP 8673D RF OUTPUT Output Level Standard Calibrated Outp
148. M esaa ot r a E nS TE ii OFF Tune the local oscillator to 3 9 GHz with an output amplitude of 8 dBm and all modulation off Select AM mode on the measuring receiver Set the audio source to a 1 kHzrate Adjust the audio source output level for 30 AM depth as read on the measuring receiver Set the audio analyzer to read the amplitude of the input signal in dB Set the audio analyzer to the dB Relative mode using the input signal from the measuring receiver as a 0 dB reference Tune the audio source from 20 Hz to 100 kHz The signal level reading on the audio analyzer should not change more than 3 dB from the reference NOTE The modulation source level may need slight adjustments to hold it at the reference level in step 5 Repeat steps 5 through 8 for the frequencies listed below Signal Local Generator Oscillator Frequency Frequency Frequency Change Modulation Level 4 0 GHz 3 9 GHz 6 7 GHz 6 6 GHz 15 0 GHz 14 9 GHz HP 8673D only 24 0 GHz 23 9 GHz 26 0 GHz 25 9 GHz 4 77 Performance Tests HP 8673C D PERFORMANCE TESTS 4 22 AM ACCURACY TESTS Specification ren Electrical Performance Characteristics Characteristics 1 AMPLITUDE MODULATION Indicated Meter Accuracy 11 of reading 100 Hz to 10 kHz rates 3 of range Accuracy Relative to 9 of reading 100 Hz to 10 kHz rates External AM Input Level 2 of range Description The Signal Generator is amplitude modulated by an a
149. MANCE TESTS 4 21 AM BANDWIDTH Specification eS cue rica 7 Characteristics Characteristics Conditions AM Bandwidth 20 Hz to 100 kHz 3 dB bandwidth de to 100 kHz 30 depth Option H41 Description The Signal Generator is amplitude modulated by an audio source and mixed down with a local oscillator to produce a modulated 100 MHz IF signal The AM depth is measured with a measuring receiver The detected audio output from the measuring receiver is input to an audio analyzer A 0 dB reference level is established on the audio analyzer at a 1 kHz modulation rate The modulation rate is then stepped from 20 Hz to 100 kHz to measure the AM bandwidth Equipment Local Oscillator asj lt indsticiwavs HP 8340A Measuring Receiver HP 8902A Audio Analyzer Source HP 8903B WAKELY a atest tai RHG DMS1 26 6 dB Attenuator HP 8493C Option 006 HP 8673C D0 SYNTHESIZED SIGNAL GENERATOR LOCAL OSCILLATOR RF OUTPUT MEASURING RECEIVER MODULAT ON OUTPUT Figure 4 32 AM Bandwidth Test Setup Procedure 1 Connect the equipment as shown in Figure 4 32 4 76 HP 8673C D Performance Tests PERFORMANCE TESTS AM BANDWIDTH cont d Specification 2 Set the Signal Generator as follows FREQUENCY sho ic40003 06524 50540 06 4 4 0 GHz OUTPUT LEVEL RANGE 0 dB OUTPUT LEVEL VERNIER 0dBm ALC ourer tieien nane O EEE TA Sp ar INFT AM oea eee iea EEE anin Eaa 100 range E
150. NIER control will be locked out until the instrument is preset or the Signal Generator is set to remote mode and then local mode The format of the program string follows the front panel sequence The program code for storing an instrument state is ST Recalling a register is done using the RC program code The program string is composed of the appropriate program code followed by a number corresponding to the appropriate register To store the current instrument settings in register 1 Local 1 Press the STO key to indicate that the instrument state is about to be saved For system compatible instruments the STO key is accessed by pressing the blue shift key followed by the RCL key HD 8673C D Example contd Program Codes Comments Operation Detailed Operating Instructions Recall and Store Registers conra 2 Press the number 1 on the numeric keypad The register is now filled with the current instrument state Subsequent operations except re storing the register will not affect the settings in register 1 To recall the instrument state stored in register 1 1 Press the RCL key to indicate that the instrument state will be recalled from one of the ten registers 2 Press the number 1 on the numeric keypad The instrument will be set to the state that was stored in register 1 This recall is non destructive so recalling register 1 later will produce the same results as this step If a register is recalled that
151. NIER is the actual RF output level The RANGE is set using the RANGE up or down key The selected RANGE 10 to 90 is displayed in the RANGE dB display The display indicates the RANGE whether in remote or local mode The local to remote and remote to local transitions do not change the output level RANGE An instrument preset will set the RANGE to 70 dB To set the RF output level using internal ALC Press the RANGE up or down key until the desired RANGE appears in the RANGE dB display Holding the key down will continue stepping the RANGE until the key is released The RANGE setting represents the maximum level available using that range The VERNIER control will allow setting output levels from 10 dB below to 3 dB above the RANGE There is a slight overlap of output level settings due to the 13 dB range of the VERNIER control For best results the VERNIER setting should be within the range of 10 to 0 dBm VERNIER settings from 0 to 3 dBm are available for observing a continuous range up to 3 dB above the RANGE setting without changing the RANGE setting 2 Adjust the VERNIER control until the sum of the RANGE and the level meter reading equal the desired RF output level The VERNIER can be used to vary the output level continuously about the set level or the RANGE up or down key can be used to step the output level in 10 dB steps If the ALC UNLEVELED annunciator lights for high output level settings the level meter will i
152. OPERATING MANUAL HP 8673C HP 8673D SYNTHESIZED SIGNAL GENERATORS Including Options 001 002 003 004 005 006 908 and 913 SERIAL NUMBERS Attached to the rear panel of the instrument is a serial number plate The serial number is in the form 0000A00000 The first four digits and the letter are the serial number prefix The last five digits are the suffix the prefix is the same for identical instruments it changes only when a configuration change is made to the instrument The suffix however is assigned sequentially and is different for each instrument This manual applies directly to instruments with serial numbers prefixed 2645A and above CA HEWLETT ER PACKARD Copyright HEWLETT PACKARD COMPANY 1987 1501 PAGE MILL ROAD PALO ALTO CALIFORNIA U S A OPERATING MANUAL PART NO 08673 90070 l Operating and Service Manual Microfiche Part No 08673 90071 Printed MAY 1987 CERTIFICATION Hewlett Packard Company certifies that this product met its published specifications at the time of shipment from the factory Hewlett Packard further certifies that its calibration measurements are traceable to the United States National Bureau of Standards to the extent allowed by the Bureau s calibration facility and to the calibration facilities of other International Standards Organization members WARRANTY This Hewlett Packard instrument product is warranted against defects in material and workmanship f
153. Only W6 Single Sweep Arm and Execute HP 8673C D Comments Operation Detailed Operating Instructions Single Sweep Mode contra The Signal Generator digital sweep is composed of discrete frequencies that are produced sequentially The minimum step size is limited to the minimum change in frequency that the Signal Generator can produce which is defined as the frequency resolution The number of steps is dependent on the frequency resolution and the frequency span For information regarding sweep time see the DWELL TIME detailed operating instruction The actual change in output frequency during a sweep will not be uniform for some frequency bands and may vary up to 2 kHz This is required to accommodate sweep step sizes that are not exact multiples of the frequency resolution The sweep steps averaged over several sweep points will be equal to the selected sweep step size An example of the averaging is defining a sweep step size of 10 kHz ata start frequency of 15 GHz The minimum tuning increment at 15 GHz is 3 kHz which means that the sweep step size can be 9 kHz or 12 kHz for exact step sizes To obtain a sweep step size of 10 kHz the Signal Generator will step by 9 kHz 9 kHz 12 kHz and then will repeat the sequence The average step size is 10 kHz even though the sweep does not execute exactly 10 kHz steps If the step size is reduced to 1 kHz the Signal Generator will step by 0 kHz 0 kHz and then 3 kHz for a 1 kHz average step si
154. Operating Instructions Description Local Procedure Remote Procedure 3 144 Steps Sweep The Signal Generator performs a sweep by stepping the RF output frequency in discrete steps between the start and stop frequency of the sweep The number of steps that the Signal Generator makes between the start and stop frequency is set by the number of steps or the sweep step size Setting the number of steps in a sweep will change the sweep step size and setting the sweep step size will change the number of steps Sweep step size is calculated by dividing the frequency span AF by the number of steps when the number of steps is set The number of steps is set by dividing the frequency span AF by the sweep step size when the sweep step size is entered The Signal Generator is capable of 1 to 9999 steps within a sweep span as long as the calculated step size is greater than 1 kHz For a sweep with one step the Signal Generator will produce the start frequency and the stop frequency Sweep step size can be set between 1 kHz and the currently defined sweep span as long as the calculated number of steps is between 1 and 9999 steps Entering a sweep step size larger than the sweep span will set the step size equal to the span and will cause the Signal Generator to issue a message To set the number of sweep steps 1 Press the STEP key to indicate that the next entry will be for the sweep step size or the number of steps The only differenc
155. Operation HP 8673C D Detailed Operating Instructions Comments cont d Programming Example Error Messages 3 106 Normal and Bypass Modes conra Automatic sweep mode will not allow a continuous sweep across one of the filter switch points in NORMAL mode The filters are switched using mechanical microwave switches and continuous sweeping across one of the mechanical switch points could cause failure due to mechanical wear Using BYPASS mode this restriction is removed for all but an amplifier switch point at 16 GHz for the HP 8673D and the switch point when tuning to a frequency below 2 GHz The RF outputis blanked when a frequency change crosses a mechanical switch point This prevents the transients associated with the mechanical switch to be suppressed at the RF output Due to the transients associated with the switching process the frequency switching time is limited at the mechanical switch points due to the RF blanking Typical frequency switching time is less than 15 milliseconds for any frequency change but RF output settling time is generally much longer The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program is used to set the Signal Generator to the mode specified by the variable Mode 10 SUB Mode_set Err Mode 20 SELECT TRIMS Mode Ignore leading and trailing spaces 30 CASE BYPASS NO FILTERS 40 P_code BY 50 CASE NORMAL FILTERED
156. P RATE STEP Key Used as a prefix to the Data and Units keys to set the number of steps or the size of each step of asweep When the entry is terminated by STEPS the number of steps is set When the entry is terminated Figure 3 5 Sweep Features and LOCAL Key 1 of 2 3 12 HD 8673C D by GHz MHz or kHz the step size is set When this key is pressed the number of steps is displayed on the left side of the FREQUENCY MHz display and the corresponding step size is displayed on the right side The maximum number of steps allowed is 9999 amp DWELL Key Used as a prefix to the Data and ms keys to set the time interval between sweep steps Press ing this key displays the present dwell time value in the FREQUENCY MHZ display for as long as the key Operation is depressed The allowable values for dwell time range from 1 to 255 ms LOCAL BISPLAY ADDRESS Key Returns the Signal Generator to jocal keyboard control from HP IB remote control provided the instrument is not in local lockout Also displays the current HP iB address in the FREQUENCY MHz display for as long as the key is depressed This key is also used to set the HP IB address Refer to the HP IB Address Selection in Section 2 for more information Figure 3 6 Sweep Features and LOCAL Key 2 of 2 3 13 Operation Qa 3 14 HP 8673C D AM AM OFF Key Disables AM AM 30 Key Enables AM and selects 30 full scale modulation for 1 volt peak
157. PULSE MODULATION contd Overshoot Ringing Video Feedthrough AMPLITUDE MODULATION Depth Rates 3 dB bandwidth 30 depth Sensitivity 30 Range 100 Range Indicated Meter Accuracy Accuracy Relative to External AM Input Level Incidental Phase Modulation Incidental FM FREQUENCY MODULATION Frequency Response Relative to a 100 kHz Rate Maximum Peak Deviation Sensitivity peak deviation Maximum input 1 Vpk into 500 nominal Indicated Meter Accuracy Accuracy Relative to External FM Input Level Incidental AM 1 10 lt 85 0 to 90 20 Hz to 100 kHz de to 100 kHz Option H41 See also indicated Meter Accuracy and Accuracy Relative to External AM Input Level 30 Vpk 100 Vpk 11 of reading 3 of range 9 of reading 2 of range lt 0 4 radians lt 0 8 radians lt 1 2 radians lt 1 6 radians lt 2 5 radians Incidental phase modulation x modulation rate 2 dB 100 Hz to 3 MHz 2 dB 3 kHz to 3 MHz The smaller of 10 MHz or fmod x 5 The smaller of 10 MHz or fmog x 10 The smaller of 10 MHz or fmog x 15 The smaller of 10 MHz or Laad x 20 1 Vpk range maximum deviation 12 of reading 3 of range 7 of reading 3 of range lt 5 0 05 0 1 GHz 0 1 6 6 7 2 26 0 GHz 6 6 7 2 GHz 0 dBm range and below Output level vernier settings lt 0 dBm lt 3 dBm for HP 8673C 16 0 to 18 6 GHz AM FM and CW modes Maximum input 1 Vpk i
158. Remote The programming string for setting a marker is composed of the frequency offset program code the positive or negative frequency offset and the units terminator The offset frequency can be programmed in units of GHz MHz kHz or Hz To program a positive frequency offset of 63 238 MHz the possible program strings are FT 063238G2 or FT63 238MZ or FT63238KZ or FT63238000HZ The alpha non numeric characters can be sent as upper or lower case or even mixed upper and lower case A positive frequency offset does not require the plus sign before the offset frequency Program Code Function Offset Frequency Positive Offset Negative Offset Negative Offset Offset Frequency Preferred Program Code HP 86738C D Comments Programming Example Error Messages Operation Detailed Operating Instructions Offset Frequency conta When using the Signal Generator as the local oscillator in a downconverter process the frequency offset can be set to the intermediate frequency IF Once the offset is set setting both the RF and the local oscillator to the same frequency will produce an IF frequency that is equal to the entered offset Using the frequency offset in conjunction with the multiplier mode is useful for harmonic mixing applications In harmonic mixing a harmonic of the local oscillator is used to downconvert a signal near the harmonic frequency Setting the multiplier equal to the ha
159. T LOCKED annunciator remains off at each frequency and that the frequency counter agrees with the Signal Generator FREQUENCY MHz display 1 count Frequency Minimum Actual MHz Frequency MHz Frequency MHz Maximum Frequency Miz 2 000 000 2 000 001 2 001 112 2 002 223 2 003 334 2 004 445 2 005 556 2 006 667 2 007 778 2 008 889 2 009 999 1 999 999 2 000 000 2 001 111 2 002 222 2 003 333 2 004 444 2 005 555 2 006 666 2 007 777 2 008 888 2 009 998 2 000 001 2 000 002 2 001 113 2 002 224 2 003 335 2 004 446 2 005 557 2 006 668 2 007 779 2 008 890 2 010 000 Set the Signal Generator frequency increment to 10 000 MHz Using the TUNE knob tune the Signal Generator to each of the frequencies listed below Verify that the NOT LOCKED annunciator remains off at each frequency and that the frequency counter agrees with the Signal Generator FREQUENCY MHz display 1 count Frequency Minimum Actual Maximum NHS Frequency MHz Frequency MHz Frequency MHz 2 090 000 2 280 000 2 470 000 2 660 000 2 850 000 3 040 000 3 230 000 3 420 000 3 610 000 3 800 000 3 990 000 4 180 000 4 370 000 4 560 000 4 750 000 4 940 000 5 130 000 5 320 000 5 510 000 5 700 000 5 900 000 6 100 000 6 600 000 2 089 999 2 279 999 2 469 999 2 659 999 2 849 999 3 039 999 3 229 999 3 419 999 3 609 999 3 799 999 3 989 999 4 179 999 4 369 999 4 559 999 4 749 999 4 939 999 5 129 999 5 319 999 5 50
160. The minimum tuning increment at 15 GHz is 3 kHz which means that the sweep step size can be9 or 12 3 145 Operation HP 8673C D Detailed Operating Instructions Comments cont d Programming Example Error Messages 3 146 Steps Sweep conta kHz for exact step sizes To obtain a sweep step size of 10 kHz the Signal Generator will step by 9 kHz 9 kHz 12 kHz and then repeat the sequence The average step size is 10 kHz even though the sweep does not execute exactly 10 kHz steps If the step size is reduced to 1 kHz the Signal Generator will step by 0 kHz 0 kHz and then 3 kHz fora 1 kHz average step size When the sweep frequency span is changed the sweep step size is recalculated by dividing the entered span by the current number of steps Entering the number of sweep steps will recalculate the sweep step size by dividing the sweep frequency span by the entered number of steps The number of steps will be adjusted until the sweep step size is equal to or larger than the frequency resolution If the number of steps times the sweep step size does not exactly equal the frequency span the last sweep point the stop frequency will not be included The number of steps may be increased automatically by the Signal Generator to offset the effect of frequency resolution on the step size For example if the sweep span is set to 1 MHz and 400 steps are selected the number of steps will be increased to 500 steps This adjustment i
161. Ty ________ 5 Wait fora period of time from 3 to 24 hours and re measure the phase change time Record the period of time between measurements To in hours and the new phase change time T9 in seconds To eee Tg ____es 6 Calculate the aging rate from the following equation aA MIE Ty Ts Te f the phase change reference for the time measurement in this case 360 i Aging Rate where 1 cycle f Signal Generator s reference output frequency 10 MHz T specified time for aging rate 24h T initial time measurement for a 360 1 cycle change Tg time between measurements Ts final time measurement for a 360 1 cycle change for example if Ti 351s T 3h Ts 349s then 1 cycle aad 24h Aging Rate 10 MHz l 35is 3849s l a i 1 306 X 107 day 7 Verify that the aging rate is less than 5 X 107 day NOTE If the absolute frequencies of the frequency standard and the Signal Generator s reference oscillator are extremely close the measurement time in steps 4and 6 T and T3 can be reduced by measuring the time required for a phase change of something less than 360 Change 1 cycle in the formula e g 180 Ye cycle 90 cycle 4 27 Performance Tests HP 8673C D PERFORMANCE TESTS 4 10 FREQUENCY SWITCHING TIME TEST Specification Description Equipment Procedure Electrical Performance Characteristics Characteristics Condit
162. UT BNC INPUT TEE Figure 4 36 FM Frequency Response Test Setup 1 Connect the equipment as shown in Figure 4 36 2 Set the Signal Generator as follows FREQUENCY Sssiedeaandndadin bovis 4000 MH OUTPUT LEVEL RANGE 0dB OUTPUT LEVEL VERNIER 0dBm FM DEVIATION range 10 MHz 4 84 HP 8673C D Performance Tests PERFORMANCE TESTS FM FREQUENCY RESPONSE cont d Procedure Contd 3 Adjust the spectrum analyzer to display the 4 GHz RF signal Set the spectrum analyzer sweep span to 1 MHz initially It will be necessary to change the sweep span for later measurements Set the other controls as needed for a calibrated display Tune the test oscillator to 100 kHz Adjust the test oscillator s output level to obtain the first carrier Bessel null Record the voltage indicated on the AC voltmeter in the table below The voltage should be approximately 0 017 Vrms Reduce the test oscillator s output level to 0 Vrms Tune the test oscillator to 3 kHz fx Adjust the test oscillator s output voltage to obtain the first carrier null Record the measured frequency and voltage in the table below Repeat steps 6 and 7 for each of the remaining frequencies listed in the table below Modulation Measured Measured Calculated Frequency Frequency Voltage Response kHz kHz mVrms dB 9 Use the following equation to calculate the FM frequency response Vx dB 20log Vio
163. a tions While sweeping the frequency changes cause a loss of phase lock and unlev eled automatic level control during the frequency change To prevent constant flashing of the front panel annunciators the response is damped to indicate only major problems during a sweep The bits of the extended status byte are also buffered and should not be used to check individual sweep points for phase lock and leveled RF output 3 129 Operation HP 8673C D Detailed Operating Instructions Programming Example Error Messages 3 130 Single Sweep Mode conrad The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program is used to set the Signal Generator to the sweep mode specified by the variable Mode 10 SUB Sweep_set Err Mode 20 OUTPUT 719 USING 2A MG Read message from 8673 30 ENTER 719 USING 2A Message to clear any old messages 40 SELECT Mode 50 CASE AUTO AUTOMATIC 60 Code W2 Auto sweep mode 70 CASE MANUAL 80 Code W3 90 CASE SINGLE ONCE 100 Code W6 Arm and begin single 110 CASE ELSE 120 DISP WARNING Invalid sweep mode specified 130 Err 1 140 SUBEXIT 150 END SELECT 160 170 OUTPUT 719 USING 2A Code 180 190 SUBEND End of subroutine The following message numbers may be displayed when activating single sweep mode Each message is explained as it pertains to activating single s
164. accepts frequency increments between 1 kHz and the maximum Signal Generator frequency 18 6 or 26 5 GHz The minimum tuning increment is dependent on the RF output frequency For output frequencies less than 6 6 GHz the minimum tuning increment is 1 kHz Above 6 6 GHz the minimum tuning incrementis 2 kHz 6 6 to 12 3 GHz 3 kHz 12 3 to 18 6 GHz or 4kHz 18 6 to 26 5 GHz Although the frequency increment can be set to 1 kHz the actual tuning increment used will be determined by the RF output frequency see comments The format of the remote programming follows the front panel key sequence To program the frequency increment the program code Flor FN is sent followed by the desired frequency increment and the units GZ MZ KZ or HZ The CW frequency is incremented or decremented in the same manner as the FREQ INCREMENT up and down keys The UP program code is equivalent to a single press of the FREQ INCREMENT up key DN is equivalent to a single press of the FREQ INCREMENT down key If a frequency increment UP will produce a frequency that is above the range of the instrument the frequency will not change and an error 02 will be issued to indicate that the frequency increment is out ot range Ifa frequency decrement DN will produce a frequency thatis below the range of the instrument the frequency will not change and an error 01 will be issued to indicate that the desired frequency is out of range To tune the CW freque
165. acy 1 0 0 dBm 1 0 GHz 10 dBm 18 6 GHz 0 dBm 18 6 GHz 10 dBm 18 6 GHz 20 dBm Low Level Accuracy 18 6 GHz 30 dBm 40 dBm 50 dBm 60 dBm 70 dBm 80 dBm 90 dBm PULSE MODULATION Rise Time Overshoot and Ringing 50 MHz Overshoot and Ringing Peak Level Accuracy 50 MHz On Off Ratic 50 MHz 6 7 GHz Rise Time Min Resuits Actuai 6 0 dBm 7 0 dBm 1 75 dBm 11 75 dBm 2 25 dBm 12 85 dBm 23 05 dBm 33 45 dBm 438 65 dBm 53 85 dBm 64 05 dBm 74 25 dBm 84 45 dBm 95 65 dBm EOE y ee 1 Max 1 00 dB 1 50 dB 2 00 dB 2 50 dB 3 50 dB 1 75 dBm 8 25 dBm 2 25 dBm 7 15 dBm 16 95 dBm 26 55 dBm 36 35 dBm 46 15 dBm 55 95 dBm 65 75 dBm 75 55 dBm 83 35 dBm 18 8 4 21 Performance Tests HP 8673C D Table 4 1 Abbreviated Performance Test Record 3 of 3 Results Min Actual Max Tast PULSE MODULATION cont d Rise Time Overshoot and Ringing 6 7 GHz Rise Time SE Se ert a 40 ns Overshoot and Ringing oe ae 30 Peak Level Accuracy 10 8 a cereal 18 8 12 GHz Rise Time EEA 40 ns Overshoot and Ringing ae AEE 25 18 GHz Rise Time aii a A 40 ns Overshoot and Ringing ee 25 HP 8673D only 19 GHz Rise Time Gaa 40 ns Overshoot and Ringing ee EA 25 AM ACCURACY Meter Accuracy 1 kHz rate 50 AM 41 5 ee eee eet 58 5 Accuracy Relative to E
166. ad Remote The programming string for setting the sweep stop frequency is composed of a program code numeric data and the units terminator The frequency may be programmed in units of GHz MHz kHz or Hz To program the Signal Generator start frequency to 16232 334 MHz the possible program strings are FB16 232334GZ or FB16232 334MZ or FB16232334KZ or FB16232334000HZ The alpha characters can be sent as upper or lower case or even mixed upper and lower case If the CW frequency changes the output frequency is valid once the SOURCE SETTLED bit of the status byte is set see Comments 3 151 Operation HP 86738C D Detailed Operating Instructions Program Codes lt a gt Comments 3 152 Stop Frequency Sweep conra Program Applicable Code SN nits a FB Start Frequency Preferred Program Code Due to the use of frequency multiplication to generate frequencies above 6 6 GHz the frequency sometimes cannot be set precisely to a desired value Frequencies below 6 6 GHz can be set to the nearest 1 kHz All frequencies between 6 6 and 12 3 GHz can be set within 2 kHz of the desired value Frequencies between 12 3 and 18 6 GHz can be set within 3 kHz of the desired value and frequencies between 18 6 and 26 5 GHz can be set within 4 kHz of the desired frequency However with careful selection of fre quency the roundoff error can be reduced to 1 kHz below 18 6 GHz and 2 kHz for freque
167. al Control Unit Ifa failure is detected the SELF TEST FAILED bit is set BIT2 FM OVERMOD Ifthe FM circuitry is overmodulated by applying more than one volt peak at the input or by exceeding the instrument capability the FM OVERMOD front panel annunciator and status bit will be set BIT 3 This bit is always set to zero BIT 4 EXTERNAL REF When the Signal Generator s rear panel panel FREQ STANDARD INT EXT switch is set to EXT the front panel EXT REF annunciator and the EXTERNAL REF status bit will be set BIT 5 NOT PHASE LOCKED If the Signal Generator is not phase locked due to _ Instrument malfunction is severely FM overmodulated has the FREQ STANDARD INT EXT switch in the EXT position with no external frequency reference or has the RF output off the NOT PHASE LOCKED status bit will be set This bitis not valid after a frequency change until the SOURCE SETTLED bit is set The NOT LOCKED annunciator on the front panel corresponds to this bit BIT 6 POWER FAILURE ON If the mains power to the Signal Generator is interrupted and then returned this bit will be set The bit can be used to verify that the line main has not been interrupted since the last time the status byte was checked BIT7 ALC UNLEVELED If the Signal Generator output level is not calibrated as indicated by the front panel ALC UNLEVELED annunciator or the amplitude modulation circuitry is being overmodulated or the RF output is off the ALC UNLEVELED bit in t
168. al Phase Modulation lt 0 05 radians for 50 depth at 1 kHz rate 50 Hz to 3 kHz bandwidth Frequency Modulation Rates 25 Hz to 25 kHz Deviation to 99 kHz Accuracy 2 at 1 kHz Oscilloscope Bandwidth 100 MHz HP 1980B 19860A Vertical Sensitivity 5 mV div Vertical Input ac de or 500 de coupled External Trigger Capability Delayed Sweep Capability One Shot Digitizer PO mq SO 1 17 General Information HP 86738C D Table 1 3 Recommended Test Equipment 3 of 4 instrument Critical Specifications Mra se Power Meter Automated adjustment programs require HP 436A D A specific test equipment Therefore no substitute is recommended Power Sensor Frequency Range 2 to 26 GHz HP 8485A PA Input Impedance 500 SWR lt 1 25 Must be compatible with power meter Power Source Range 60 Vac to 240 Vac California Instruments P Variable Frequency 48 to 400 Hz 501TC 800T D Frequency AC Accuracy 2 Hz Preamp Power Amp Preamp HP 8447D P i Frequency 100 kHz to 1 8 GHz Gain 26 2 dB Output Power gt 7 dBm Noise Figure lt 8 5 dB Impedance 500 Power Amp HP8447E P Frequency 100 kHz to 1 8 GHz Gain 22 5 dB Note HP 8447F is a dual Output Power gt 6 dBm amplifier and will satisfy Noise Figure lt 5 dBm both requirements Impedance 500 Probe 10 1 Must be compatible with the oscilloscope HP 10081A C P A Pulse Generator Rate 10 Hz to 4 MHz HP 8116A or HP 8013B C P A Rise an
169. alk Functions si ear ees 3 38 1 13 3 5 Response to a Clear Message 3 39 1 16 3 6 HP IB Program Codes 3 42 3 7 Index of Detailed Operating Instructions 3 45 1 20 3 8 Error Messages ovis oss sosv ews eens 3 101 are 4 1 Abbreviated Performance Test Record 4 20 3 1 4 2 High Level Accuracy Test Record 4 55 3 31 4 3 Low Level Accuracy Test Record 4 58 3 33 4 4 Performance Test Record 4 91 Vii vill HP 8678C D Safety Considerations SAFETY CONSIDERATIONS GENERAL This product and related documentation must be reviewed for familiarization with safety markings and instructions before operation This product is a Safety Class I instrument pro vided with a protective earth terminal BEFORE APPLYING POWER Verify that the product is set to match the avail able line voltage and the correct fuse is installed SAFETY EARTH GROUND An uninterruptible safety earth ground must be provided from the main power source to the prod uct input wiring terminals power cord or sup plied power cord set Any interruption of the protective grounding conductor inside or outside the instrument or disconnecting the pro tective earth terminal will cause a poten tial shock hazard that could result in personal injury Grounding one conduc tor of a two conductor outlet is not suffi cient protection In addition verify that a common ground exists betw
170. als For example to level a signal with an amplitude of 50 dBm after a signal path with losses of 30 dB the attenuation can be set to 10 dB range 10 dB to place the Signal Generator at an RF output level of only 20 dBm The internal circuitry generates RF levels of 10 dBm and higher before introducing attenuation to increase the dynamic range of the Signal Generator When selecting the proper range for external leveling the lowest and highest gain loss should be calculated The range is then set 10 dB higher than the level required to keep the internally generated RF level near 10 dBm HP 8673C D Comments cont d Application Example Error Messages Operation Detailed Operating Instructions Diode Automatic Level Control conta Using a range lower than 0 dB has the advantage of improving the source match and reducing the noise floor of the Signal Generator at the expense of reducing maximum available power The external ALC circuitry is used to adjust the Signal Generator s output level until the detected voltage at the external ALC input is correct If high harmonics or spurious signals are present in the signal that is being detected they will affect level flatness This is especially important when using external amplifiers and mixers within the signal path For example if the RF signal levelis 10 dBm and the second harmonicis at 0 dBm the actual detected power will be 11 milliwatts 10 4 dBm instead of
171. amplitude of the IF signal stays between these two levels Set the oscilloscope s sweep mode to triggered or NORM This sweep mode will not trigger the digitizer until the external trigger signal is received Using the FREQ INCREMENT keys set the Signal Generator to the start frequency 2 000 000 MHz HP 86738C D Performance Tests PERFORMANCE TESTS FREQUENCY SWITCHING TIME TEST coni d Procedure 24 Press the digitizer STORE M1 key on the oscilloscope and then step the Signal cont d Generator to the stop frequency 6 600 000 MHz The oscilloscope should digitize the switching waveform as the frequency changes The waveform should be as shown in Figure 4 15 Required Delay Figure 4 15 Amplitude Recovery Switching Waveform 25 Or Set the oscilloscope to delayed sweep Set the oscilloscope s delay time to the time the IF frequency amplitude suddenly increases Using the FREQ INCREMENT keys reset the Signal Generator s frequency to the start frequency 26 D 27 J Press the digitizer STORE M1 key on the oscilloscope and step the Signal Gener ator to the stop frequency with the FREQ INCREMENT key The oscilloscope should digitize the switching waveform as the frequency changes The waveform should now look like that shown in Figure 4 16 28 Measure the amplitude recovery time The measurement is the time from the left graticule of the display to the last time the IF signal amplitude is out
172. anccscad 2 4 Rack Mounting beake veneuetusa neues 2 4 Storage and Shipment 00 e cece ee eeee 2 4 BOOST ca eles tito hee ck vee en ees 2 4 PAGKAGING Chae ceddlessse rae eines kere 2 5 Section I OPERATION Introduction ois Ka d Rad ae KR cies nE eei 3 1 System Compatibility e 3 1 Operating Characteristics 3 1 Local Operation cccpcccccccceverecess 3 1 Remote Operation c cece ence een eneeee 3 1 Operator s Checks cic sledsicliawaeien suas esas 3 1 Operator s Maintenance 2 0 cc ee ee eee ee 3 1 Battery Replacement c 3 1 General Instructions ccc ccc cece ewer e cence 3 4 POI ON oes chess cds deans BAG Ko eee 3 4 Frequency Standard Selection 3 4 Additional Operating Information 3 5 Autoreak eo Ook ice arse dramat ean tat oe Te N 3 5 ALC Automatic Level Control 3 5 Contents Page PULSE Modulation hinted eta ties 3 6 SWEEP Mode in MASTER SLAVE Configuration c5asese se incelssiudaakG bxa was 3 6 Operator s Checks eh bed athe 3 16 Basic Functional Checks 0 0 00 0 3 16 HP IB Functional Checks yasala 3 24 Remote and Local Messages and the LOCAL Key or oroia Eno aiaa ada 3 24 Receiving the Data Message 3 25 Sending the Data Message S 3 25 Local Lockout and Clear Lockout Set Local Messages ccc eee e eee eeee 3 26 Clear Moggeng
173. ance Tests PERFORMANCE TESTS POWER LINE RELATED SPURIOUS SIGNALS TESTS cont d Procedure HP 8673D only cont d 24 Set the spectrum analyzer frequency span to 5 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level 25 Tune the Signal Generator to 20 000 000 MHz 26 Tune the local oscillator to 20 000 020 MHz gt 1 kHz offset __ SES lt 55 dBc 27 Set the spectrum analyzer frequency span to 500 Hz Adjust the spectrum analyzer controls to place the peak of the 20 kHz IF signal on the top graticule line Verify that the line related harmonics of the Signal Generator do not exceed the values shown below Record the highest spurious signal level in each offset band 18 6 26 0 GHz lt 300 Hz offset nm lt 38 ABe 28 Set the spectrum analyzer frequency span to 1 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level 300 Hz 1 kHz offset lt 48 Boe 29 Setthe spectrum analyzer frequency span to 5 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level gt 1 kHz offset lt 53 dBe 4 47 Performance Tests 4 15 OUTPUT LEVEL AND FLATNESS TESTS PERFORMANCE TESTS Specification f Electrical Performance Conditions Characteristics Characteristics Qutput Level 11 to 100 dBm 05 to 2 0 GHz Normal Mode 5 to 100 dBm 2
174. annual cleaning procedures are detailed in Section VIII Service 4 4 PERFORMANCE TEST RECORD Results of the performance tests may be tabulated in Table 4 4 Performance Test Record The Per formance Test Record lists all of the performance test specifications and the acceptable limits for each specification If performance test results are recorded during an incoming inspection of the in strument they can be used for comparison during periodic maintenance or troubleshooting The test results may also prove useful in verifying proper adjustments after repairs are made 4 5 EQUIPMENT REQUIRED Equipment required for the performance tests is listed in Table 1 3 Recommended Test Equipment Any equipment that satisfies the critical specifi cations given in the table may be substituted 4 6 TEST PROCEDURES It is assumed that the person performing the fol lowing tests understands how to operate the speci fied test equipment Equipment settings other than those for the Signal Generator are stated in general terms For example a test might require that a spectrum analyzer s resolution bandwidth be set to 100 Hz however the sweep time would not be specified and the operator would be expected to set that control and other controls as required to obtain an optimum display It is also assumed that the technician will select the cables adapters and probes required to complete the test setups illustrated in this section Perfo
175. applied to the AM IN connector AM 100 Key Enables AM and selects 100 full scale modulation for 1 volt peak applied to the AM IN connector AM IN Connector BNC female connector with an input impedance of 600 ohms 1 voit peak sets full scale modulation as selected by the AM 30 or 100 key AM depth varies linearly with the input signal level FM DEVIATION FM DEVIATION MHz OFF Key Disables FM FM DEVIATION Keys 03 1 3 1 3 and 10 Enables FM and selects the peak deviation sensitivity in MHz obtained when a signal is applied to the FM iN con nector The peak deviation is read on the meter This deviation is not corrected when an external fre quency multiplier is used For example if a frequency doubler is being used the actual frequency deviation will be twice that shown on the meter FM IN Connector BNC female connector with an input impedance of 50 ohms 1 voit peak gives full scale modulation Deviation varies linearly with the input signal level Deviation ranges are controlled by the FM DEVIATION keys PuLse PULSE OFF Key Disables pulse modulation NORM Normal Mode Key Turns RF output on when the signal to the PULSE IN connector is greater than 2 4 volts COMP Complement Mode Key Turns RF output on when the signal to the PULSE IN connector is less than 0 4 volts PULSE IN Connector BNC female connector with an input impedance of 50 ohms Accepts TTL levels Figure 3 6 Modulation Featur
176. ar the status byte the program code CS must be sent or the status byte and extended status 3 139 Operation HP 8673C D Detailed Operating Instructions Remote Procedure contd 3 140 Status Byte and Polling conta byte must be read The clear status command CS will clear both the status byte and the extended status byte If clearing the status changes the extended status byte the CHANGE IN EXTENDED STATUS bit will be set in the status byte This enables the controller to monitor the status byte using a serial poll until the extended status byte changes Reading both status bytes after the output status command OS will clear both bytes after they are read To read the extended status byte the program code OS is sent and then the status byte and extended status byte are read into the controller Since the extended status bits are latched the extended status byte may indicate that a problem exists that has already been corrected For example ifthe RF output is turned off the NOT LOCKED bit and the ALC UNLEVELED bit will be set If the RF output is then turned on and the extended status byte read the NOT LOCKED and ALC UNLEVELED bit will still be set To read the current instrument status the status should be cleared CS and then the extended status byte will reflect current conditions Service Request SRQ The Signal Generator can generate a service request whenever one of the bits of the status byte is set Howev
177. asuring receiver should be less than 4 kHz Record the reading in the table below 13 Repeat steps 8 through 12 for the frequencies listed in the table below Signal Generator Local Oscillator Incidental FM Frequency Level Frequency Level Actual Limit 6 2 GHz 6 1 GHz lt 4 kHz 12 8 GHz 12 2 GHz lt 8 kHz 18 0 GHz 17 9 GHz lt 12 kHz HP 8673D only 24 0 GHz 23 9 GHz lt 16 kHz 26 0 GHz 25 9 GHz lt 25 kHz 4 83 Performance Tests HP 86738C D PERFORMANCE TESTS 4 24 FM FREQUENCY RESPONSE Specification Electrical Performance Characteristics Characteristics FM Frequency Response Relative to 100 kHz rate 100 Hz to 3 MHz 30 and 100 kHz V ranges 3 kHz to 3 MHz 300 kHz and 1 3 and 10 MHz V ranges Description The test oscillator is tuned to 100 kHz and the output level is adjusted to obtain the first carrier Bessel null This output level and the 100 kHz rate are the references for later calculations At other modulation rates the output level is set and measured for the first carrier null The measured voltage and the rate are then compared to the established reference to determine frequency response Equipment AC Voltmeter HP 400E Frequency Counter HP 5343A Spectrum Analyzer HP 8566B Test Oscillator HP 8116A HP 8673C D SYNTHESIZED SPECTRUM ANALYZER SIGNAL GENERATOR TEST OSCILLATOR OUTPUT BNC RE FM IN INPUT TEF OUTPUT FREQUENCY AC VOLTMETER COUNTER OOo INP
178. at the instrument is settled and the extended status byte is valid after a preset the following procedure should be used 1 Set the Signal Generator to 2 GHz and then preset the instrument with the program string FR2GZRCO0 Monitor the status byte using a serial poll until the SOURCE SETTLED bit is set Clear the status and prepare the extended status byte with the program string CSOS8 3 141 Operation HP 8673C D Detailed Operating Instructions Comments cont d Programming Example 3 142 Status Byte and Polling conra If the above procedure is followed the extended status byte will be valid and the preset will be complete by the time the extended status is read If a selected device clear i e CLEAR 719 or a device clear i e CLEAR 7 are used a settling time of about 2 seconds is required before the extended status byte is valid and the source is settled Setting the Signal Generator to 2 GHz before the clear will allow the preceding procedure to be followed starting with step 2 after the preset The SOURCE SETTLED bit is set once the affected parameter has settled If a clear status is executed before this bit is set from a previous command the bit will be set after the status byte has been cleared and before the parameter being programmed has changed For example if the instrument is preset and the status cleared as part of a frequency change before the Signal Generator has settled the SOURCE SETTL
179. at this frequency to reduce harmonics 3 5 6 0 GHz 6 0GHz A tracking bandpass filter is switched in from 6 to 22 GHz 18 6 for the HP 8673C to reduce harmonics and subharmonics above 6 6 GHz 16 0 GHz An amplifier is switched in to increase output power above 16 GHz HP 8673D only 22 0 GHz A high pass filter is switched in to reduce subharmonics HP 8673D only HP 8673C D Programming Example Error Messages Operation Detailed Operating Instructions Auto Sweep Mode conta The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The following program is used to set the Signal Generator to the sweep mode specified by the variable Mode 10 SUB Sweep_set Err Mode 20 OUTPUT 719 USING 2A MG Read message from 8673 30 ENTER 719 USING 2A Message to clear any old messages 40 SELECT Mode 50 CASE AUTO AUTOMATIC 60 Code W2 Auto Sweep mode 70 CASE MANUAL 80 Code W3 90 CASE SINGLE ONCE 100 Code W6 Arm and begin single 110 CASE ELSE 120 DISP WARNING Invalid sweep mode specified 130 Err 1 140 SUBEXIT 150 END SELECT 160 170 OUTPUT 719 USING 2A Code 180 190 SUBEND End of subroutine The following message numbers may be displayed when activating automatic sweep mode Each message is explained as it pertains to activating automatic sweep mode For a more complete description of the
180. ated adjustment programs require HP 85B 82987A specific test equipment Therefore no substi 00085 15002 tute is recommended 00085 15008 00085 15005 Frequency Range 2 to 26 GHz HP 8473C Frequency Response 1 5 dB Frequency Range 2 to 35 MHz HP 1110B 1 16 Crystal Detector HP 8678C D General Information Table 1 3 Recommended Test Equipment 2 of 4 bi ee Recommended Digital Voltmeter Automated adjustment programs require HP 3456A P A T specific test equipment No substitute is recommended Foam Pads 43 X 58 cm 17 X 23 in 5 em 2 in thick P 2 required Frequency Counter Range 10 MHz to 26 5 GHz HP 5343A P A l Resolution 100 Hz 10 MHz Frequency Standard Output 0 1 Vrms a E Frequency Standard Long Term Stability Better than 10 day HP 5065A Local Oscillator Level 10 MHz to 18 6 GHz 7 dBm 18 6 to 26 GHz 5 dBm Single Sideband Phase Noise and Spurious Signals Same as HP 8340A Range 10 MHz to 26 GHz HP 8340A P A Logic Pulser TTL compatible HP 546A RHG DMS1 267 Response 1 to 26 GHz VSWR LO lt 2 5 1 VSWR RF lt 4 0 1 Modulation Analyzer Frequency Range 150 to 990 MHz HP 8902A 11722A D A Input Level 20 to 13 dBm Amplitude Modulation Rates 25 Hz to 25 kHz Depth to 99 Accuracy 2 at 1 kHz Flatness 0 5 Demodulated Output Distortion lt 0 3 for 50 depth lt 0 6 for 90 depth Incident
181. ated output level control To set the Signal Generator for external diode leveling 1 Connect the diode to the remote point using a directional coupler For calibrated output levels the diode must be operating in the square law region If the diode is above the square law region typically gt 20 dBm a change in the VERNIER setting of 1 dB will produce less than 1 dB change in actual RF output level If the diode is in the linear region a 1 dB change in the VERNIER setting will produce a 0 5 dB change in the leveled power The ALC circuitry will still produce leveled power output for any diode operating region but meter calibration and HP IB control will be uncalibrated 2 Set the Signal Generator range to at least 10 dB above the range required for the desired RF output level The range may have to be adjusted to compensate for losses and gains in the RF signal path If the RF signal path will have a relatively high loss a higher Signal Generator range will be required 3 Connect the diode output to the external ALC input of the Signal Generator The detector output typically varies from 0 05 to 5 millivolts for the square law region 4 Pressthe ALC DIODE key to set the Signal Generator to external diode ALC mode 5 Connect a power meter to the output of the directional coupler the output port not the coupled port The power meter will be used to calibrate the output level to the Signal Generator level meter HD 86738C D L
182. ator is in the normal mode If the BYPASS indicator is lighted the Signal Gen erator is in the BYPASS mode The key next to the indicators is used to change from BYPASS to NORMAL mode or from NORMAL to BYPASS mode The program code BY is used to set the Signal Generator to the BYPASS mode The program code NM is used to set the Signal Generator to NORMAL mode The controller cannot read the present state NORMAL or BYPASS over the HP IB For output levels near the maximum specified level the controller should attempt to set the level first using NORMAL mode to take advantage of the improved spectral purity with the filtering Ifthe level cannot be set the automatic level control is unleveled the controller can set the mode to BYPASS to increase the available RF power output BYPASS mode is not valid for RF output frequencies below 2 GHz When changing frequency from above 2 GHz to below 2 GHz NORMAL mode will always be selected If the initial mode was BYPASS a message will be issued to indicate that BYPASS is not functional below 2 GHz BYPASS mode will not be restored when the frequency again goes above 2 GHz Program a BY BYPASS Mode NM NORMAL Mode The filters are included inside the automatic leveling control feedback loop so the addi tion of the filtering does not affect absolute level accuracy or flatness in any way Maximum available power is affected due to the extra loss involved in the filtering process 3 105
183. ator to 3000 000 MHz 3 Set the OUTPUT LEVEL RANGE to 60 dB Adjust the VERNIER to 0 dBm 4 Set the spectrum analyzer controls to display the fundamental signal Set the resolution bandwidth to 1 kHz and the frequency span per division to 10 kHz 4 42 HP 86738C D Performance Tests PERFORMANCE TESTS NON HARMONICALLY RELATED SPURIOUS SIGNALS CW AND AM MODES TESTS Contd Procedure 5 Set the spectrum analyzer controls so that the displayed signal is at the top grati cont d cule line 6 Set the Signal Generator s RANGE to 0 dB Adjust the VERNIER to 10 dBm Do not adjust the spectrum analyzer amplitude calibration The top graticule line now represents 50 dBe 7 Tunethespectrum analyzer to any desired frequency in search of non harmonically related spurious signals Verify that any signals found are non harmonically related and are not generated by the spectrum analyzer Verify that the spurious signals are below the specified limits Record the results Carrier Spurious Signal Spurious Signal Frequency Frequency Amplitude 8 Repeat steps 2 through 7 for any desired carrier frequency from 0 05 to 6 6 GHz Record the results Checking non harmonically related spurious signals from 0 05 to 6 6 GHz provides a high level of confidence that the instrument meets its published specifications from 0 05 to 26 GHz Carrier Spurious Signal Spurious Signal Frequency Frequency Amplitude 4 43 Performance Tests HP
184. ator to the Signal Generator s FM IN connector Adjust the external oscillator amplitude until the middle scale 0 to 1 indicates 100 kHz deviation The required external oscillator amplitude will be approximately 1 volt peak or 0 707 volts rms Remote The programming string for setting the 100 kHz FM range is D3 The amplitude and frequency of the modulating signal must be set by programming the external modul ating signal source The alpha character D can be sent as upper or lower case Program wat FM Off FM Off FM 0 03 MHz Range FM 0 1 MHz Range FM 0 3 MHz Range FM 1 MHz Range FM 3 MHz Range FM 10 MHz Range An Auto Peak operation occurs any time Auto Peak is enabled and an FM range is changed to maintain optimum operation With FM selected an Auto Peak operation does not turn off Auto Peak but instead sets the FM range to 0 03 MHz during the Auto Peak operation EM meter accuracy is specified for 100 kHz rates only To determine the meter accuracy at other modulation rates the FM frequency response specification is added to the meter accuracy The FM frequency response specification is a specification that indi cates how much the power level atthe FM IN connector may have to be adjusted to pro vide the desired and indicated FM peak deviation This correction is required due to the frequency response characteristics of the FM circuitry for rates other than 100 kHz The following program is written in BASIC for HP 900
185. be set to trigger on any valid Signal Generator frequency and can be individually enabled or disabled Each active marker will add a distinct frequency to the sweep even iftwo markers are set to the same sweep marker frequency For example if two markers are set for 3 GHz and 3 GHz is also a valid point in the frequency sweep three sweep points will be generated at 3 GHz See the comments section for more details on marker priority and marker frequency points To set and activate a sweep frequency marker Press the MKR key to indicate that a marker will be set activated or turned off 2 Enter the marker number that is to be set using the numeric keypad Valid marker numbers are one through five 3 Enter the desired marker frequency using the numeric keypad Ifa mistakeis made while entering the frequency press the backspace key until the incorrect digit disappears Continue entering the correct digits until the frequency displayed in the FREQUENCY MHz display is correct 4 Press the appropriate units key The frequency may be entered in GHz MHz or kHz Once the units key is pressed the displayed frequency will be adjusted to display MHz and the sweep marker frequency will be displayed until the units key is released Setting the sweep marker frequency will activate the sweep marker If the sweep marker frequency is between the sweep start and stop frequency pressing the MKR key will display the marker number to indicate that it is activ
186. btain a sweep step size of 10 kHz the Signal Generator will step by 9 kHz 9 kHz 12 kHz and then will repeat the sequence The average step size is 10 kHz even though the sweep does not execute exactly 10 kHz steps Ifthe step size is reduced to 1 kHz the Signal Generator will step by 0 kHz 0 kHz and then 3 kHz for a 1 kHz average step size in the 3 kHz resolution frequency band 3 53 Operation HP 86738C D Detailed Operating Instructions Comments cont d 3 54 Auto Sweep Mode conra Sweeps from a higher frequency to a lower frequency can be accomplished by setting the start frequency higher than the stop frequency This combination results in a negative frequency span as indicated when the frequency span is displayed Negative frequency spans can only be entered by setting the start frequency higher than the stop frequency An Auto Peak operation is performed whenever the RF output frequency is more than 50 MHz from the frequency at which the last Auto Peak operation was performed The Auto Peak operation optimizes the Signal Generator performance at the current frequency The Auto Peak operation produces small changes in the RF output level as the peaking is performed For applications requiring fastest sweeps Auto Peak may be disabled However with Auto Peak disabled modulation performance and maximum output power may be degraded The time required for the Auto Peak operation is not included in the dwell time setting Th
187. but the last sweep points will all be at the highest valid frequency A filter or amplifier band crossing occurred during automatic sweep mode Only one sweep will occur and then the sweep will stop Filter switchpoints may be bypassed by using BYPASS mode Auto Peak malfunction This indicates that the instrument may require service HP 8673C D Description Local Procedure Operation Detailed Operating Instructions Marker Frequency Sweep The Signal Generator has five markers that can be used during a sweep to activate rear panel control signals when selected frequencies are generated These control signals can be used to generate distinctive calibrated frequency markers on an external display Using the Signal Generator s markers provides up to five easily identified display markers at known frequencies When a marker is activated an extra frequency point at the sweep marker frequency will be generated during a sweep and the BLANKING MARKER and TONE MKR signals will be activated The rear panel BLANKING MARKER signal is used to produce a 5 volt dc level to intensify a portion of the trace on a CRT display Z axis input The signal level will be zero volts de for non marker frequencies The TONE MKRis a5 kHz signal that can be used to amplitude modulate the RF output signal of the Signal Generator or can be summed into an external display to generatea distinctive marker on the displayed trace Each of the five markers can
188. byte is sent with the bus EOI line true thus terminating the message 3 42 Sending the Status Byte Message After receiving a Serial Poll Enable bus command SPE and when addressed to talk the Signal Generator sends a Status Byte message The mes sage consists of one 8 bit byte of which 7 bits cor respond to the pattern and descriptions for the Request Mask The remaining bit bit 7 is the RQS Request Service bit see Figure 3 11 The RQS bit is set when one of the other seven conditions exists and that condition has been enabled by the Request Mask Bits 1 6 and 8 might be true regardless of conditioning by the Request Mask However if a condition has not been selected by the mask it cannot cause the RQS bit to be set true Extended Status Byte A second status byte is available but can only be accessed via the Output Status function see explanation under Sending the Data Message Bit 3 of the Status Byte indi cates whether a change has occurred in the Ex tended Status Byte If Bit 3 is true the second status byte should be accessed via the Output Sta tus function to determine the cause of the status change The bit pattern can be interpreted with the information in Figure 3 11 3 43 Clearing the Status Byte Once the Signal Generator sets the SRQ bus line true it is no longer allowed to alter the Status Byte If a bit has been enabled and the condition occurs after the SRQ bus line has been set true the HP 8673
189. can in the other mode This is useful when the system controller is slow enough data rate lt 1000 bytes second that it cannot take advantage of the Deferred mode s transfer speed or when switching time independ ent of message length is more important than program execution speed Deferred Execution Mode This ASCII mode must be selected by sending the program code 2 In this mode the Signal Generator accepts strings up to 96 characters at a time executing the string upon receiving an EOS message The Signal Gen erator produces its own EOS message upon receipt of the 96th character in a string If a block of strings containing more than 96 characters is sent the first 96 characters are accepted and the Signal Generator holds the bus busy until it exe cutes them Then the next 96 characters are accepted and so on until the entire block is ac cepted If only one string of less than 96 characters is sent the Signal Generator accepts the strings and frees the bus allowing program execution to continue Binary Mode The Signal Generator s Request Mask is programmed in binary format Also learn mode data is sent and received in binary Binary data is always processed in the Immediate Execu tion mode 3 33 Sending the Data Message The Signal Generator can send Data messages when addressed to talk It remains configured to talk until it is unaddressed to talk by the con troller To unaddress the Signal Generator the contr
190. cation 4 Adjust the front panel CAL control until the ALC UNLEVELED annunciator is extinguished Set the VERNIER for a0 dBm indication on the level meter and then adjust the CAL control until the power meter reads 10 dBm 5 The output level can now be set by adjusting the VERNIER for the desired output level as read on the level meter Setting the range to 0 dB will reduce the output level 3 65 Operation HP 8673C D Detailed Operating Instructions Example cont d Program Codes lt gt Comments 3 66 Diode Automatic Level Control contd by 10 dB However setting the range lower than 0 dB will not change the output level until the ALC goes unleveled due to insufficient output power to overcome the addi tional loss in the RF signal path Remote 1 Perform the above steps 1 to 4 to calibrate the external ALC circuitry 2 Set the output level remotely by programming vernier settings between 10 and 0 dBm Changing the range will have the same affects as described in step 5 above Program Code External Diode Leveling Mode Using external diode leveling mode has the advantages of fast response time with a relatively simple leveling setup The disadvantages of diode leveling is the limited dynamic range of the square law region and the absence of temperature compensation 23 dB of dynamic range is typically available using the Signal Generator s 0 and 10 dB ranges In addition amplitude modulat
191. ched from the start level L1 to the stop level L2 The oscillo scope should digitize the switching waveform as the frequency and level changes The waveform should be similar to the waveform shown in Figure 4 24 NOTE Ifa negative detector is used channel 1 should be inverted If channel 1 is not inverted the actual waveforms will be the inverse of those shown 10 Set the oscilloscope to delayed sweep mode Set the oscilloscope s delay time to the time corresponding to about a division before the digitized signal s amplitude settles into the final value The measurement will be the time required before the signal stays within 1 division of the middle horizontal graticule the final ampli tude Setting the delay time to begin the sweep at this point will allow more detail to be digitized since the oscilloscope will digitize a smaller portion of the switching waveform 4 61 Performance Tests HP 8673C D PERFORMANCE TESTS OUTPUT LEVEL SWITCHING TIME TEST cont d Procedure cont d 2 89 mV div Figure 4 24 Output Level Switching Waveform 11 Rerun the program entered in step 9 by executing the command RUN 100 Press the digitizer key on the oscilloscope when instructed to by the program The oscilo scope should digitize the switching waveform with greater detail The waveform should now look like that shown in Figure 4 25 12 Measure the level switching time by observing the digitized signal on the oscillo
192. cially important when using external amplifiers and mixers within the signal path For example ifthe RF signal levelis 10 dBm and the second harmonic is at 0 dBm the actual detected power will be 11 milliwatts instead of 10 milliwatts 10 dBm For a detected voltage of 1 volt for 10 dBm the detected signal will be at 1 1 volts for the 11 milliwatt signal This will cause a leveling error of about 0 83 dB Example 1 External ALC over the range of 0 to 10 dBm is required The RF signal path exhibits an insertion loss of 6 dB that varies 12 dB over the frequency range To control the output level over a0 to 10 dBm range an amplifier capable of 16 dBm 10 dBm 4 dB 2 dB is required The range selected for this application depends mainly on the gain of the amplifier If we assume a gain of 10 dB the optimum Signal Generator range is 0 dB The overall signal path gain varies from 12 to 16 dBm To reduce the level to 10 dBm would require 10 dB of attenuation The range is set 10 dB above this requirement or 0 dB Example 2 The IF output of a mixer is to be leveled at 20 dBm The conversion loss of the mixer is 10 dB and varies 3 dB over the frequency range Using the Signal Generator as the RF source for the mixer the power meter is connected to the IF port of the mixer using a 10 dB directional coupler The attenuation of the signal path is 10 dB and varies 3 dB For an IF level of 20 dBm the RF port must be at a level of ap
193. cription A spectrum analyzer is used to measure the change in output power when the pulse modulator is switched from complement mode to normal mode Equipment Spectrum Analyzer HP 8566B HP 8673C D SYNTHESIZED SPECTRUM ANALYZER SIGNAL GENERATOR OL ee Ouse ao oaco RF OUTPUT APC 3 5 CABLE Figure 4 26 Puise ON OFF Ratio Test Setup Procedure 1 Connect the equipment as shown in Figure 4 26 2 Set the Signal Generator as follows FREQUENCY j4c4 ccnp ine ssckanaieees 200 MHz OUTPUT LEVEL RANGE 0dBm OUTPUT LEVEL VERNIER 10 dBm PULSE 535 Potash ee EE T on COMPL AM estes ids Sac ace eee eee OFF FM DEVIATION 2 ciiaw axe cues ae nao OFF SWEEP MODE c cccscccesccecees OFF 3 Set the spectrum analyzer controls as follows Center Frequency S 100 MHz Frequency Span ccc eee ees 100 kHz Resolution Bandwidth 1 kHz Video Bandwidth co erates ho wx o Baie ae wae os 100 Hz Sweep Time ecusvaeragekenestca we 3 sec 4 Adjust the spectrum analyzer controls to establish a reference at the top graticule line 4 64 HP 8673C D Performance Tests PERFORMANCE TESTS PULSE ON OFF RATIO TEST cont d Procedure NOTE cont d The spectrum analyzer must not be in the gain compression region for this measurement If a 3 dB increase in the Signal Generator output level does not produce a3 dB increase in the level of the displayed signal the spect
194. curacy Relative to External FM Input 9 10 11 12 13 Tune the test oscillator to 100 kHz with an output amplitude of 0 707 Vrms Set the Signal Generator FM DEVIATION range to 0 8 MHz The measuring receiver should indicate FM deviation within the limits listed in the following table Record the reading in the table Repeat step 10 using the FM deviations and levels listed in the following table Record the readings in the table Tune the Signal Generator to 6 7 GHz Set the FM DEVIATION range to 0 38 MHz Tune the local oscillator to 7 2 GHz 4 87 Performance Tests HP 8673C D PERFORMANCE TESTS EXTERNAL FM ACCURACY AND METER ACCURACY cont d Procedure cont d FM Test Oscillator Low Actual Deviation Level Vrms Limit Deviation 27 kHz 90 kHz 270 kHz 249 kHz 14 Set the test oscillator s output level to 0 707 Vrms 15 Read the FM deviation on the measuring analyzer Verify that the measured deviation is within the limits shown in the following table Record the readings 16 Repeat steps 12 through 15 using the frequencies listed in the above table Record the readings Signal Generator Local Oscillator low Actual High Frequency Frequency Limit Deviation Limit i i 6 7 GHz 270 kHz mma 380 kHz 12 3 GHz 270 kHz Ww 8330 kHz 18 6 GHz 270 kHz i I 8330 kHz 4 88 HP 86738C D Performance Tests PERFORMANCE TESTS 4 26 INCIDENTAL AM Specificatio
195. cy are changing For applications that require fastest execution the SOURCE SETTLED bit of the status byte can be used Once the bit is set the output is valid and the program may continue If the frequency is programmed and the status byte is not checked the program should wait at least the frequency switching speed time before assuming the output valid For controllers using buffered output an additional wait is required so that the RF output is not used until at least the specified frequency switching time elapses after the Signal Generator has received the program string If the status byte is to be used to monitor settling the program string that sets the frequency should be prefaced with the program code CS This will clear any previous setting of the SOURCE SETTLED bit to avoid an incorrect indication For frequency changes greater than 50 MHz an Auto Peak operation is performed by the Signal Generator The Auto Peak operation optimizes the Signal Generator performance at the set frequency The Auto Peak operation produces small changes in the RF output level as the peaking is performed In some cases the Auto Peak may require longer than the frequency switching time specification For applications requiring fastest switching speed Auto Peak may be disabled However with Auto Peak disabled modulation performance and maximum output power may be degraded The SOURCE SETTLED bit of the status byte is set when the Auto Peak operation is co
196. cy has been entered using the numeric keypad Remote The programming string for setting the sweep delta frequency is composed of a program code numeric data and the units terminator The frequency may be programmed in units of GHz MHz kHz or Hz To program the Signal Generator delta frequency to 4500 MHz the possible program strings are FB4 5GZ or FB4500MZ or FB4500000KZ or FB4500000000HZ The alpha characters can be sent as upper or lower case or even mixed upper and lower case Setting the sweep delta frequency will not change the CW frequency when sweep is off Program Applicable GZ DF AFrequency KZ HZ Preferred Program Code Due to the use of frequency multiplication to generate frequencies above 6 6 GHz the sweep start and stop frequencies recalculated when the sweep delta frequency is entered may not be set precisely to one half of the sweep delta frequency below or above the center frequency Frequencies below 6 6 GHz can be set to the nearest 1 kHz All 3 61 Operation HP 8673C D Detailed Operating Instructions Comments contd Programming Example 3 62 Delta Frequency Sweep conta frequencies between 6 6 and 12 3 GHz can be set within 2 kHz of the desired value Frequencies between 12 3 and 18 6 GHz can be set within 3 kHz of the desired value and frequencies between 18 6 and 26 5 GHz can be set within 4 kHz of the desired frequency However with careful selectio
197. cy standard with long term stability greater than 1x10 day is connected to the trigger input The time required for a specific phase change is measured immediately and after a period of time The aging rate is inversely proportional to the absolute value of the difference in the measured times Description Equipment Oscilloscope HP 1980B Frequency Standard HP 5065A NOTE The internal 10 MHz reference oscillator will typically take 24 to 48 hours to reach its specified rate after instrument storage or shipment In some cases if extreme environmental conditions were encountered during storage the reference oscillator could take as long as one week to achieve its specified aging rate HP 8673C D SYNTHESIZED SIGNAL GENERATOR FREQUENCY STANDARD OSCILLOSCOPE VERTICAL OUTPUT ENPUT Figure 4 11 Internal Time Base Aging Rate Test Setup Procedure 1 Connect the equipment as shown in Figure 4 11 NOTE This test requires a waiting period of 3 to 24 hours between initial an final measurements 2 Set the rear panel FREQ REFERENCE INT EXT switch to the INT position 4 26 HD 86738C D Performance Tests PERFORMANCE TESTS INTERNAL TIME BASE AGING RATE cont d Procedure 3 Adjust the oscilloscope controls for a stable display of the 10 MHz Signal Generator cont d reference output 4 Measure the time required for a phase change of 360 one cycle Record the time T1 in seconds
198. d Fall Times lt 5 ns Output Impedance 500 Output Level 0 to 3 5V Pulse Width 80 ns to 2 us Signal Generator Output Level 5 to 20 dBm at 240 MHz HP 8340A or HP 8640B Because the signatures dependent upon the model selected only the models listed are approved for usage Signature Analyzer Frequency Range 20 Hz to 300 kHz Resolution Bandwidth 3 Hz minimum Frequency Span Division 20 Hz minimum Noise Sidebands gt 90 dB below CW signal 3 kHz offset 100 Hz IF bandwidth Input Level Range 0 to 70 dBm Log Reference 70 dB dynamic range in 10 dB steps Accuracy 0 2 dB Tracking Generator 0 dBm to 11 dBm Spectrum Analyzer HP 3585A l 1 18 HP 8673C D General Information Table 1 3 Recommended Test Equipment 4 of 4 Recommended instrument Critical Specifications Madel Spectrum Analyzer Frequency Range 10 MHz to 22 GHz HP 8566B System Frequency Span Division 1 kHz minimum Amplitude Range 0 to 70 dB Noise Sideband gt 75 dB down 30 kHz from signal at 1 kHz resolution bandwidth ae G e Support Kit Required for servicing and troubleshooting HP 11726A Sweep Oscillator Center Frequency 150 to 200 MHz HP 8340A or Center Frequency Resolution 0 1 MHz HP 86222B 8620C Sweep Range 10 and 200 MHz Termination 500 500 BNC HP 11598A Test Oscillator Level 0 to 3V into 500 or 3000 HP 3335A Range 10 kHz to 10 MHz
199. d in single sweep and there is a 100 millisecond sweep delay for the pen to raise or lower To set the Signal Generator for a single sweep Set the desired sweep parameters 2 Press the SINGLE SWEEP MODE key to arm the single sweep The key indicator will light and the RF frequency will be set to the start frequency 3 Press the SINGLE SWEEP MODE key again to begin the single sweep The sweep will continue to the stop frequency and then reset to the armed state 3 127 Operation HP 8673C D Detailed Operating Instructions Local Procedure contd Remote Procedure Example Program Codes 3 128 Single Sweep Mode contd If anew center frequency is entered when single sweep modeis active the start and stop frequencies will be reset and the single sweep will be set to the armed state in preparation for a sweep Tuning the frequency will also move the sweep center frequency and reset the single sweep Pressing the SINGLE SWEEP MODE key during a sweep will reset the sweep to the armed state A 100 millisecond wait is executed both at the beginning of a single sweep and at the end of the sweep This wait is required for the pen of an external recorder to lower at the beginning of a sweep and raise at the end of the sweep Single sweep is armed with the program code W4 or W5 Once the sweep is armed it can be executed with the program code W4 A single sweep can be armed and executed with the program code W6 The co
200. d upper and lower case HP 86738C D Program Codes Comments Programming Example Error Messages Operation Detailed Operating Instructions Dwell Time Sweep conta Program Gede Sweep Dwell Time MS The Signal Generator digital sweep is composed of discrete frequencies that are produced sequentially The time spent at each of the sweep steps is controlled by the dwell time The actual time between frequencies is dependent on step size band crossings modulation used and whether Auto Peak is enabled Description Units With Auto Peak enabled an Auto Peak operation will be performed for every 50 MHz change in frequency from the last frequency where an Auto Peak operation was performed For sweep step sizes greater than 50 MHz an Auto Peak operation will be performed for each sweep step Depending on the adjustment of the instrument the Auto Peak operation can add 30 to 100 milliseconds per step Generally small step sizes over a narrow span will provide the shortest time between steps Dwell times less than 5 milliseconds will not produce a true phase locked signal for all sweeps An algorithm is used to provide the shortest phase lock without waiting for complete settling The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program is used to set the sweep dwell time to the number specified by the variable Expected The desired value must be between 1 and 255 milliseco
201. d whenever the RF frequency _ changes from the heterodyne band 01 to 1 999999 GHz to another band or when the frequency changes from another band to the heterodyne band Using a higher VERNIER setting with the lowest possible RANGE setting when setting RF output level will help to minimize the effect of the broadband noise 3 125 Operation HP 8673C D Detailed Operating Instructions Programming Example Error Messages 3 126 RF Output On Off contd The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program will enable the RF output if the parameter is set to ON or disable the output if the parameter is set to OFF 10 SUB Rf_output Err State 20 30 SELECT UPCS TRIMS State Check for action 40 CASE OFF 50 OUTPUT 719 USING 3A RFO Turns RF output off 60 CASE ON 70 OUTPUT 719 USING 5A CSRF1 Turns RF on and Auto Peaks 80 Wait_settle Wait for Auto Peak to finish 90 V SPOLL 719 Get the status byte 100 IF NOT BIT V 3 THEN GOTO Wait_settie 110 CASE ELSE 120 DISP ERROR Invalid parameter amp State amp was passed 130 Err 4 140 END SELECT 150 160 SUBEND The following message may be displayed when enabling the RF output The message is displayed as it pertains to enabling the RF output For a more complete description of the message see the MESSAGES detailed operating instructions 90 An Auto Peak
202. dB 1 50 dB 2 10 dB 2 30 dB 2 70 dB 2 70 dB amp 0 2 dB per 10 dB step 2 25 dB 2 00 dB 2 55 dB 2 85 dB 3 30 dB 3 30 dB amp 0 2 dB per 10 dB step Add 0 75 dB to remote program ming absolute level accuracy 0 1 dB 1 00 dB 1 50 dB 2 00 dB 2 50 dB 3 50 dB lt 25 ms gt 50 dB gt 80 dB lt 30 ns lt 20 ns lt 40 ns lt 100 ns 50 Hz to 1 MHz lt 0 0001 lt 300 ns Same as in CW mode 1 5 dB 1 5 1 0 dB General Information 10 dBm output level range _ 0 dBm output level range 10 dBm output level range 20 dBm output level range 30 dBm output level range lt 30 dBm output level range 10 dBm output level range 0 dBm output level range 10 dBm output level range 20 dBm output level range 30 dBm output level range lt 30 dBm output level range Absolute level accuracy specifi cations include allowances for detector linearity temperature flatness attenuator accuracy and measurement uncertainty 0 05 to lt 2 0 GHz 0 05 to 6 6 GHz 0 05 to 2 3GHz gt 0 05 to 18 6 GHz Y 0 05 to 26 0 GHz 50 250 MHz 250 26 0 GHz AUTO PEAK executed 0 05to 0t GHz Stis 0 1 to lt 2 0 GHz 2 0 to 26 0 GHz gt When internally leveled no restriction when unleveled 0 05 to lt 2 0 GHz 2 0 to 26 0 GHz General Information Table 1 1 Specifications 5 of 7 HP 8673C D Electrical Characteristics Performance Limits mas
203. de lt 40 dBe 0 05 to 1 2 GHz lt 60 dBe 1 2 to 18 26 GHz HP 8673C lt 60 dBe 1 2 to 26 GHz HP 8673D Subharmonics and Multiples lt 60 dBe mode subharmonics may Thereof exist at lt 50 dBe for output frequencies between 21 and 22 GHz HP 8673D HP 8673C Description This test checks the amplitude of various harmonics of the Signal Generator s output signal In the multiplied frequency bands gt 6 6 GHz subharmonics and multiples harmonics of the internal fundamental signal are also checked for specific levels Reasonable care must be taken to ensure that the harmonics are not being generated by the spectrum analyzer E Harmonics are tested at high VERNIER settings 3 dBm Subharmonics and multi ples are tested at low VERNIER settings 10 dBm where the feedthrough of the funda mental signal is largest in relation to the multiplied signal Equipment Spectrum Analyzer HP 8566B HP 8673C D SYNTHESIZED SPECTRUM ANALYZER SIGNAL GENERATOR RF OUTPUT APC 3 5 CABLE Figure 4 18 Harmonics Subharmonics and Multiples Test Setup Procedure 1 Connect the equipment as shown in Figure 4 18 2 Tune the Signal Generator to 100 000 MHz and set the output level to 3 dBm 3 Set the spectrum analyzer s controls to display the fundamental signal Set the resolution bandwidth to 10 kHz the input attenuation to 40 dB and the sweep span to 100 MHz Adjust the controls to set the displayed sig
204. e HP 8673D only 26 000 GHz ee 74 dBe H 100 kHz offset from carrier 1 999 960 MHz S 105 dBe 6600 GHz eee re 105 dBe 12 300 GHz a 104 dBc 18 600 GHz Sea 100 dBe HP 8673D only 26 000 GHz joes 98 dBe HARMONICS SUBHARMONICS AND MULTIPLES Harmonic or Fundamental Subharmonic MHz Number 50 000 250 000 500 000 1000 000 1500 000 2000 000 4000 000 6000 000 8000 000 8000 000 10000 000 10000 000 11000 000 11000 000 14000 000 14000 000 16000 000 16000 000 18000 000 18000 000 no hbo mw be BS 2 2 2 4 93 Performance Tests Para No 4 12 4 14 4 94 Table 4 4 Performance Test Record 4 of 13 HARMONICS SUBHARMONICS AND MULTIPLES cont d Fundamental Harmonic or MHz Subharmonic Number HP 8678D only 20000 000 a 20000 000 L 20000 000 Vs 22000 000 1 22000 000 Ya 22000 000 L 24000 000 la 24000 000 S 24000 000 Ys 26000 000 ke 26000 000 Y2 26000 000 H NON HARMONICALLY RELATED SPURIOUS SIGNALS CW AND AM MODES Carrier Spurious Signal Frequency Frequency 3000 000 MHz ere neers 0 05 2 0 GHz 3000 000 MHz 2 0 26 0 GHz 0 05 2 0 GHz 2 0 26 0 GHz POWER LINE RELATED SPURIOUS SIGNALS 0 05 2 0 GHz lt 300 Hz offset 300 Hz 1 kHz offset gt 1 kHz offset lt 300 Hz offset 300 Hz 1 kHz offset gt 1 kHz offset lt 300 Hz offset 300 Hz 1 kHz offset gt 1 kHz offset lt 300 Hz offset 300 Hz
205. e If the sweep marker frequency is not between the sweep start and stop frequency it will not be displayed as active until the start or stop frequencies are reset to place the sweep marker frequency within the sweep A sweep marker is deactivated by pressing the MKR key entering the marker number using the numeric keypad and then pressing the MKR OFF units key All five markers can be deactivated by pressing the MKR key and then pressing the MKR OFF units key The sweep marker frequency for a given marker can be displayed by pressing the MKR key and then entering the marker number using the numeric keypad The sweep marker frequency for that marker will be displayed as long as the marker number key is pressed This sequence is also used to activate a marker so reading a sweep marker frequency will activate the marker 3 93 Operation HP 8673C D Detailed Operating Instructions Local Procedure contd Remote Procedure Example 3 94 Marker Frequency Sweep conra The active markers can be displayed by pressing and holding the MKR key The active markers will be displayed in the FREQUENCY MHz display in the order in which they will occur For example if marker 3 is set to 15 GHz and marker 5 is set to 10 GHz the marker display will display 5 and then 3 as long as both sweep marker frequencies are within the current sweep Each of the five markers can be programmed to any frequency within the Signal Generator s fre
206. e SPE bus com mand by sending an 8 bit byte when addressed to talk If the instrument is holding the SRQ control line true issuing the Require Service message bit 7 RQS bit in the Status Byte and the bit representing the condition causing the Require Service message to be issued will both be true The bits in the Status Byte are latched but can be cleared upon receiving the Clear Status CS program code executing the Output Status function or executing a serial poll while the SRQ control line is held true tL Q Status Byte 3 33 Operation gt HP 8673C D Table 3 3 Message Reference Table 2 of 2 HP IB Appii Message cable Status Response interface Functions The Signal Generator responds to a Parallel Poll Enable PPE Bit bus command by sending a bit on a controller selected HP IB data line Commands Control lines and Interface Functions are defined in IEEE Std 488 1978 Knowledge of these may not be necessary if your controller s manual describes programming in terms of the twelve HP IB Messages shown in the left column Complete HP IB capability as defined in IEEE Std 488 and ANSI Std MC1 1 is SH1 AH1 T5 TEO L3 LEO SR1 RLA PPi DC1 DT1 and C0 Local Mode contd applications Local lockout disables the LOCAL key and allows return to local only under program control NOTE Return to local can also be accomplished by turning the Signal Genera
207. e front panel entry format To program a frequency display multiplier the program code MY is sent followed by the multiplier and the units XF The multiplier can be read by the controller using the output active program code suffix To read the multiplier send the program codes MYOA and then read the multiplier If the multiplier is read as a string the format will be the program code MY followed by the multiplier and then the units program code HZ HP 8673C D Example Program Codes Comments Operation Detailed Operating Instructions Multiplier Mode conra To set a frequency display multiplier of 2 Local 1 Press the blue shift key to access the shifted functions The shifted functions are printed in blue above certain keys 2 Press the MULT key to indicate that a display multiplier is to be entered 3 Enter a 2 using the number keypad The entered value should be displayed in the FREQUENCY MHz display 4 Press the X FREQ units key to complete the sequence The FREQUENCY MHz display should show the entered multiplier 2 until the X FREQ key is released The entered display multiplier can be read by pressing the shift key and then pressing and holding the MULT key The entered multiplier will be displayed until the key is released Once a multiplier is entered all frequencies will be displayed after being multiplied by the entered multiplier The offset frequency if entered will not be multiplied by the disp
208. e places throughout this manual 1 4 MANUAL CHANGES SUPPLEMENT Instruments manufactured after the printing of this manual may be different from those docu mented in this manual The manual for this newer instrument is accompanied by a Manual Changes supplement The supplement contains change information that explains how to adapt this manual to the newer instrument In addition to change information the supplement may contain information for correcting errors in the manual To keep the manual as current and as accurate as possible Hewlett Packard recommends that you periodically request the latest Manual Changes supplement The supplement is identified with the manual print date and part number both of which appear on the manual title page Compli mentary copies of the supplement are available from Hewlett Packard For information concerning a serial number pre fix that is not listed in the Manual Changes supplement contact your nearest Hewlett Packard office 1 5 DESCRIPTION The HP 8673C Synthesized Signal Generator hasa frequency range of 0 05 to 18 6 GHz 0 01 to 18 6 GHz overrange The HP 8673D Synthesized Signal Generator has a frequency range of 0 05 to 26 0 GHz 0 01 to 26 5 GHz overrange The output is leveled and calibrated from 12 dBm to 100 dBm depending on the frequency and options For additional information see Table 1 1 AM FM and pulse modulation modes can be selected Frequency output lev
209. e 0 50 6 6 GHz 1 Hz bandwidth CW mode 64 dBe 30 Hz offset from carrier 70 dBe 100 Hz offset from carrier 78 dBc 1 kHz offset from carrier 86 dBe 10 kHz offset from carrier 110 dBe 100 kHz offset from carrier 6 6 12 3 GHz 58 dBe 30 Hz offset from carrier 64 dBe 100 Hz offset from carrier 72 dBe 1 kHz offset from carrier 80 dBe 10 kHz offset from carrier 104 dBe 100 kHz offset from carrier 12 3 18 6 GHz 54 dBe 30 Hz offset from carrier 60 dBc 100 Hz offset from carrier 68 dBe 1 kHz offset from carrier 76 dBe i 10kHz offset from carrier 100 dBe 100 kHz offset from carrier HP 8678D only 18 6 26 0 GHz 52 dBe 30 Hz offset from carrier 58 dBc 100 Hz offset from carrier 66 dBe 1 kHz offset from carrier 74 dBc 10 kHz offset from carrier 98 dBe 100 kHz offset from carrier Description The RF output of the Signal Generator is mixed with a local oscillator to obtain a 40 kHz or 200 kHz IF signal The noise sidebands are observed on a spectrum analyzer Correc tion factors are applied to the readings to compensate for using the spectrum analyzer in the log mode local oscillator noise contributions and bandwidths wider than 1 Hz NOTE Normally phase quadrature needs to be maintained between the Signal Generator and the local oscillator for true phase noise measurement However the additional amplitude noise components are so small that they are not significa
210. e 4 5 HP 8673C D SYNTHESIZED SIGNAL GENERATOR aL PULSE NERATOR OSCILLOSCOPE A an ow S aad a nn 0 a 1 ag any a z p a L 2 RF PULSE PULSE EXTERNAL EXTERNAL 50Q 2 OUTPUT INPUT OUTPUT TRIG OUT TRIG IN VERTICAL INPUTS 70 dB 20 00 ATTENUATOR PREAMPLIFIER STEP 1 26 GHz EEA SPECTRUM ANALYZER Figure 4 4 Low Frequency Pulse Test Setup 4 12 HP 86738C D Performance Tests ABBREVIATED PERFORMANCE TESTS PULSE MODULATION TEST cont d Procedure cont d Figure 4 5 Risetime Overshoot and Ringing Measurement 5 Measure the pulse rise time overshoot and ringing Record the results Rise Time 10 to 90 Overshoot and ringing lt 20 ns lt 25 Peak Level Accuracy at 50 MHz 6 7 8 Adjust the pulse width on the pulse generator for a 100 ns RF pulse as displayed on the oscilloscope Switch Signal Generator to PULSE OFF mode Adjust the oscilloscope vertical sensitivity for a display 5 divisions above the pulse base line The peak of the CW signal is now the CW peak reference level NOTE Do not adjust the vertical position controls after the CW peak reference level and pulse base line have been set CW PEAK REF S td T AVERAGE PEAK LEVEL y R PULSE LEVEL 5 DIV PULSE BASE LINE Lag 100 ns gt Figure 4 6 Pulse Peak Level Accuracy Measurement 4 13 Performance Tests HP 8673C D ABBREVIATED PERFORMANCE TESTS
211. e RANGE is read as a string the format will be the program code RA followed by the RANGE in dBm and then the units terminator DM dBm 3 119 Operation HP 86738C D Detailed Operating Instructions Remote Procedure cont d Example Program Codes gt 3 120 Range Output Level conta In local mode the Signal Generator keeps track of the VERNIER setting to within 1 dB When switching to remote mode the local RF level setting is preserved This feature also allows the controller to read the local VERNIER setting by briefly switching to remote to read the VERNIER setting and then returning the Signal Generator to local mode The VERNIER setting is read by sending the program codes VEOA and then reading the setting The Signal Generator will send the VERNIER setting in fundamental dBm units Ifthe VERNIER setting is read as a string the format will be the program code VE followed by the VERNIER setting in dBm and then the units terminator DM dBm The RF output level is read directly by sending the program codes LEOA and then reading the RF output level The Signal Generator will send the RF output level in fundamental dBm units If the RF output level is read as a string the format will be the program code LE followed by the RF output level in dBm and then the units terminator DM dBm The program codes AP or PL can also be used in place of LE but the Signal Generator will always send the program code LE when t
212. e Signal Generator can be restored to that configuration at a later time The learn mode requires a controller that can transfer information in binary form After receiving an L1 program code Front Panel Learn Mode and when addressed to talk the Sig nal Generator sends 2 ASCII characters and A followed by a string of 94 8 bit binary bytes con taining information on the front panel configura tion This binary data can then be stored in the controller s memory for future use In addition as each configuration goes out onto the bus itis also stored in the Signal Generator s register 9 The most straight forward way to program the system controller is to use a loop to read 96 binary charac ters and store them in an array When the Signal Generator is addressed to listen the binary data can be returned to it in 96 byte strings When the Signal Generator detects the A it will expect the next 94 characters to be in the learn mode string A checksum is embedded in the string so that possible errors in the storage or transmission of the data will be detected and the input will be ignored Whenever data is being transferred between con troller and Signal Generator it must do so in unin terrupted strings If a data string is broken or interrupted the data could be lost or offset and misinterpreted by the Signal Generator An offset of data bytes can persist through later data strings until the Signal Generator is eventually s
213. e automatic level control ALC bandwidth is increased when sweep mode is acti vated This provides fast response to switching transients when sweeping In addition AM bandwidth is typically increased by 2 5 times The front panel annunciators are filtered in sweep mode to prevent false indications While sweeping the frequency changes cause a loss of phase lock and unleveled auto matic level control during the frequency change To prevent constant flashing of the front panel annunciators the response is damped to indicate only major problems during a sweep The bits of the extended status byte are also buffered and should not be used to check individual sweep points for phase lock and leveled RF output The Signal Generator has several frequencies where mechanical switches are actuated to change the internal microwave signal path The automatic sweep is only permitted one sweep across one of the mechanical switch points Using the BYPASS mode will enable sweeps across one of the filter switch points at the expense of spectral purity The message key will light and an error code will be issued to indicate that a band crossing occurred in automatic sweep mode The various switch points are given below Frequency n 2 0 GHz The microwave signal path is switched for downconversion when switching from above 2 GHz to below 2 GHz 2 0 GHz A low pass filter is switched in to reduce harmonics 2 0 3 5 GHz 3 5 GHz A low pass filter is switched in
214. e contents saved in that register Shifted function STO Used as a prefix to anumeric key a single difgit 1 9 to identify the storage register to save current instrument settings in an internal register RCLO is used to preset the front panel Refer to Simplified Operation in this section for a list of preset conditions Data Keys 0 9 and Used with Function keys that is FREQUENCY FREQ INCR and sweep function keys and Units keys to set value selectable parameters Data keys 1 9 are also used with STO and RCL to identify the storage register HP 8673C D The backspace key clears one digit at a time Starting with the least significant digit It is used oniy during data entry and before any Units key is pressed 6 LINE Switch Applies power to the lower unit of the Signal Generator when set to the ON position When set to the OFF position and is setto the ON posi tion the FREQUENCY MHz display will show a mov ing dot display until is set to the ON position Units Keys MKR GFF STEPS ms GHz MHz and kHz Used as a suffix to Function and Data keys to set value selectable parameters Frequency entries can terminate in GHz MHz or KHz but they are always displayed in MHz The MKR OFF STEPS ms key serves as a terminator for setting the number of steps in a sweep the dwell time in ms or as a means of turning off markers The selected function automatically determines the applicable
215. e euwapk ew meee Off PULSE i oe essed T TE Tn Nhi hens Off 3 Tune the local oscillator to 2 0 GHz with an output amplitude of 7 dBm and all modulation off 4 Select AM mode on the measuring receiver Set the measurement frequency of the measuring receiver to 50 MHz 4 16 HP 8673C D ABBREVIATED PERFORMANCE TESTS AM ACCURACY TESTS contd Performance Tests Procedure 5 Set the modulation source to 1 kHz Adjust the output level to obtain 50 AM as cont d read on the measuring receiver 6 The AM meter on the Signal Generator should indicate 50 AM 8 5 Record the reading Accuracy Relative to External AM Input 41 5 58 5 7 Set the audio source frequency to 10 kHz with an output amplitude of 0 636 Vrms as read on the digital voltmeter This corresponds to 90 AM depth 8 Read the actual AM depth on the measuring receiver The reading should be within 10 1 of 90 AM Record the reading in the table below 9 Repeat steps 7 and 8 with the frequencies and modulation rates listed in the table below HP 8673C only 10 Set the HP 8673C as follows PREQUENCY aag eR A ie KREIGIS 18 6 GHz OUTPUT LEVEL RANGE 0 dBm OUTPUT LEVEL VERNIER 3 dBm 11 Tune the local oscillator to 18 5 GHz with an output amplitude of 7 dBm 12 Set the modulation source frequency to 10 kHz Adjust the output level for 0 636 Vrms as read on the digital voltmeter 13 Read the AM depth on the m
216. e frequency read will not be correct during sweep Note that the latter method indicates the rounded frequency while the former does not To set the frequency to 16 232 334 MHz Local 1 Press the FREQUENCY key 2 Key in 16 282 334 using the numeric keypad The FREQUENCY MHz display should show 16 232 334 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the MHz units key to finish the sequence The FREQUENCY MHz display should now show the entered frequency The FREQUENCY MHz display should now be right justified The frequency could also have been entered as 16 232334 GHz or 16232334 kHz The only difference is the placement of the decimal point and the units key pressed after the frequency has been entered using the numeric keypad Remote The programming string for setting the CW frequency is composed of a program code numeric data and the units terminator The frequency may be programmed in units of GHz MHz kHz or Hz To program the Signal Generator to 16 232 334 MHz the possible program strings are 3 71 Operation HP 8673C D Detailed Operating Instructions Example coni d Program Codes gt Comments 3 72 Frequency CW conta FR16 232334G2Z or FR16232 334MZ or FR16232334KZ or FR16232334000H2Z In addition the program code could be CF or CW instead of FR The alpha characters can be sent as upper or lower case o
217. e in entering the two parameters is the units terminator 2 Enter the desired number of steps using the numeric keypad If a mistake is made while entering the number of steps press the backspace key until the incorrect digit disappears Continue entering the correct digits until the number of steps in the FREQUENCY MHz display is correct 3 Pressthe STEPS key to indicate that the number of steps rather than the sweep step size has been entered The sweep step size will be calculated and the sweep step size and the number of steps will be displayed until the STEPS key is released If the entered value does not produce a sweep step size equal to or greater than the frequency resolution the number of steps will be reduced until a valid sweep step size is obtained The number of steps must be between 1 and 9999 steps If the sweep step size is adjusted the entered value of number of steps is retained for use when other sweep parameters are changed This feature enables the sweep parameters to be entered in any order without restrictions due to previous sweep parameters that do not affect the final values For example ifthe number of steps is entered as 200 with the current sweep span defined as 100 kHz the number of steps will be adjusted to be 100 1 kHz resolution and a message will be issued However changing the sweep span to 200 kHz will restore the number of steps to 200 without having to re enter the value The Signal Generator accepts a
218. e indicator on the key will be lighted whenever the RF output is enabled and extinguished when the RF output is disabled Pressing the key repeatedly will toggle the RF output between the on and off state The Signal Generator RF output is turned on or off using a single program code The program code to turn the RF output on is RFI or R1 The program code to turn the RF output offis RFO or RO To turn off the RF output Local If the indicator in the RF ON OFF key is not lighted the RF outputis already off Ifthe indicator is lighted press the RF ON OFF key once Remote The programming string for setting the RF output level to off is RFO or RO The alpha characters can be sent as upper or lower case or even mixed upper and lower case Program iis RF Output Off RF Output Off RF Output On RF Output On Turning on the RF output will start an Auto Peak operation To determine when the RF output is settled the source settled bit of the status byte can be monitored Once the bit is set the RF output is settled and the application may continue For frequencies below 2 GHz a broadband amplifier is used as part of a heterodyne process The broadband noise below 2 GHz is much higher due to the wide bandwidth of the amplifier Due to the higher broadband noise low level power meter readings will be affected due to addition of the broadband noise power to the measured signal To eliminate the effect the power meter must be re zeroe
219. e nts teaduaeuws HP 8447F 20 dB Attenuator 00 0 cece eee HP 8493C Option 020 HP 8673C D SYNTHES ZED SIGNAL GENERATOR LOCAL OSCILLATOR RF OUTPUT RF OUTPUT 20 dB MIXER STEP _16 T ETAR STEP 1 SPECTRUM ANALYZER POWER SENSOR POWER METER 40 dB AMPLIFIER INPUT 1 OUTPUT Figure 4 3 Level Accuracy Test Setup Procedure High Level Accuracy Test 1 Zero and calibrate the power meter Set the power meter to dBm mode 2 Connect the Signal Generator to the power meter as shown in Figure 4 3 3 Tune the Signal Generator to 1 0 GHz 4 Set the OUTPUT LEVEL RANGE to0 ee Adjust the VERNIER for a front panel meter reading of 0 dBm 5 Peak the Signal Generator output with the AUTO PEAK key Performance Tests HP 86738C D ABBREVIATED PERFORMANCE TESTS LEVEL ACCURACY TESTS cont d Procedure contd High Level Accuracy Test contd 6 9 10 Observe the power meter reading The reading should be within the limits specified Record the reading 1 0 GHz 0 dBm LD dBm n tH1 75 dBm Adjust the Signal Generator s VERNIER for a front panel meter reading of 10 dBm leave RANGE set to 0 dB Observe the power meter reading The reading should be within the limits specified Record the reading 1 0 GHz 10 dBm 11 75 dBm ___ 8 25 dBm Tune the Signal Generator to 18 6 GHz Adjust the VERNIER for a front panel meter reading of 0 dBm 11 Observe the powe
220. e of 60 MHz 7 OntheSlave unit select a 50 MHz offset as follows press the FREQ INCR key and then key in 50 MHz Press FREQ INCREMENT lt 7 key This changes the center frequency of the slave unit from 9 000 GHz to 9 050 GHz 8 Press and bold the SWEEP START key on the Slave unit Check the display for a 50 MHz offset The display should read 6050 MHz 9 Initiate the desired sweep mode AUTO MANUAL or SINGLE by selecting the desired sweep mode on the Master unit Any number of slave units up to the limit of the HP IB can be controlled with a single Master unit To add another Slave unit connect the additional Signal Generator to the Master unit with an HP IB cable set the Slave unit s HP IB address to 40 and enter the desired sweep parameters When entering sweep step size or number of steps use identical values for the Master and Slave units If identical values are not entered the sweeps will not track identically resulting in increasing or decreasing offsets as the sweep progresses Adjusting the TUNE knob on the Slave unit will tune the sweep center frequency toa different value resulting in loss of the desired frequency offset between the Master and Slave units HP 8673C D Operation Detailed Operating Instructions Master Slave Sweep conta Comments When in MANUAL mode the Master unit can be used to reset both units to the sweep cont d start frequency To do so press the SINGLE key then press the MANUAL k
221. e power meter Tune the Signal Generator frequency to 50 0 MHz Set the OUTPUT LEVEL RANGE to 10 dB Adjust the VERNIER for a power meter reading of 11 dBm Peak the Signal Generator output with the AUTO PEAK key Tune the Signal Generator in 50 MHz steps from 50 0 MHz to 2 0 GHz while observ ing the power meter reading Record the frequency at which minimum power occurs Frequency Tune the Signal Generator to the recorded frequency Adjust the VERNIER for a power meter reading of 11 dBm Tunethe Signal Generator from 50 0 MHz to 2 0 GHz in 100 MHz steps while observ ing the power meter readings Ensure that the specified maximum leveled output power level is met Tune the Signal Generator to 2 0 GHz Set the NORMAL BYPASS switch to NORMAL Adjust the VERNIER for a power meter reading of 5 dBm 4 5 Performance Tests HP 8673C D ABBREVIATED PERFORMANCE TESTS OUTPUT LEVEL AND FLATNESS TESTS cont d Procedure 11 cont d 12 14 15 16 17 18 19 20 Tune the Signal Generator in 100 MHz steps from 2 0 to 16 0 GHz while observing the power meter readings Record the frequency at which minimum power occurs Frequency Tune the Signal Generator to the recorded frequency Adjust the VERNIER for a power meter reading of 5 dBm Tune the Signal Generator from 2 0 GHz to 16 0 GHz in 100 MHz steps while observ ing the power meter readings Ensure that th
222. e program strings are FLQ15GZ or FI1 5MZ or FI1500KZ or FI1500000HZ In addition the program code could be FN or F1 instead of F1 The alpha characters can be sent as upper or lower case or even mixed upper and lower case To increment the frequency in 1 5 MHz steps send the program code UP To decre ment the frequency in 1 5 MHz steps send the program code DN A single step will be made for each program code received To increment or decrement more than one step senda program string with multiple program codes For Een DN DN DN DN will decrement the frequency four times Frequency Incremeni Codes Program Codes Program Applicable Units GZ Frequency Increment MZ KZ HZ Function Frequency Tuning Cades Program Funetion UP Increment CW center frequency by frequency increment by step size in MANUAL sweep mode DN Decrement CW center frequency by frequency increment by step size in MANUAL sweep mode IF MANUAL sweep mode only see MANUAL SWEEP NO Disable TUNE knob not active in remote or local mode Ni Enable TUNE knob active in local mode only Preferred Program Code 3 78 HP 8673C D Comments Operation Detailed Operating Instructions Frequency Increment and Tuning conta Due to the use of frequency multiplication to generate frequencies above 6 6 GHz the minimum tuning increment is increased Frequencie
223. e specified maximum leveled output power level is met Tune the Signal Generator to 2 0 GHz Set the NORMAL BYPASS switch to BYPASS Adjust the VERNIER for a power meter reading of 8 dBm Tune the Signal Generator in 100 MHz steps from 2 0 GHz to 16 0 GHz while observ ing the power meter readings Record the frequency at which minimum power occurs Frequency Tune the Signal Generator to the recorded frequency Adjust the VERNIER for a power meter reading of 8 dBm Tune the Signal Generator in 100 MHz steps from 2 0 GHz to 16 0 GHz while observ ing the power meter readings Ensure that the specified maximum leveled output power level is met Refer to the table below Tune the Signal Generator to 16 0 GHz Repeat steps 9 through 19 starting at 16 0 GHz with 200 MHz steps Use NORMAL BYPASS switch settings and output levels listed in the table below Signal Frequency Minimum Specified Worst Case L Generator Range Power Level Frequency HP 8673C NORMAL 16 0 18 0 GHz 2 0 dBm BYPASS 16 0 18 0 GHz 5 0 dBm HP 8673D NORMAL 16 0 26 0 GHz 6 0 dBm BYPASS 16 0 26 0 GHz 7 0 dBm HP 8673C D Performance Tests ABBREVIATED PERFORMANCE TESTS OUTPUT LEVEL AND FLATNESS TESTS cont d Procedure Level Flatness Test cont d NOTE The flatness specification for power output is not referenced to a particular frequency The specification represents the total power variation over the entire frequency range 21 Tun
224. e sweep at one half the sweep delta frequency above the center frequency Setting the CW frequency when sweep is off will also reset the sweep center frequency to the same value Setting the center frequency or sweep delta frequency will automatically recalculate the appropriate sweep start and stop frequencies and will recalculate the sweep step size Resetting the sweep start or stop frequency will reset the sweep center frequency if in sweep mode or the CW frequency if sweep is off The sweep delta frequency will be recaiculated whenever the sweep start or stop frequency is changed The sweep delta frequency can be set as low as 1 kHz to as high as the maximum frequency of the Signal Generator If the sweep start frequency is set above the sweep stop frequency a negative sweep delta frequency will be stored Entering the start frequency above the stop frequency is the only way to enter a negative frequency span To set the Signal Generator to a specific sweep delta frequency 1 Press the SWEEP FREQ AF key to indicate that the next entry will be for sweep delta frequency 2 Enter the desired frequency using the numeric keypad If a mistake is made while entering the frequency press the backspace key until the incorrect digit disappears Continue entering the correct digits until the frequency displayed in the FREQUENCY MHz display is correct 3 Press the appropriate units key The frequency can be entered in GHz MHz or kHz Once the
225. e sweep center frequency as long as the key is held HP 86738C D Remote Procedure Example Program Codes Operation Detailed Operating Instructions Center Frequency Sweep conta The Signal Generator accepts any frequency within its specified frequency range Above 6 6 GHz the programmed frequency may be rounded by the Signal Generator to be compatible with the 2 3 or 4 kHz resolution at the programmed frequency see comments The format of the remote programming follows the front panel key sequence To program the sweep center frequency the program code CF is sent followed by the desired frequency and the units GZ MZ KZ or HZ The sweep center frequency can be read by the controller using the output active program code suffix To read the center frequency the program codes CFOA are sent and then the frequency is read The Signal Generator will send the frequency in fun damental Hz units f the frequency is read as a string the format will be the program code CF followed by the center frequency in Hz and then the units terminator Hz To set the sweep center frequency to 16 232 334 MHz Local 1 Press the FREQUENCY key 2 Key in 16232 334 using the numeric keypad The FREQUENCY MHz display should show 16232 334 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the MHz units key to finish the sequence The FREQUENCY MHz display should now s
226. e the Signal Generator to 50 0 MHz Set the OUTPUT LEVEL RANGE to 0 dB Set the VERNIER for a power meter reading of 5 dBm 22 Set the power meter mode to dB Relative 23 Tune the Signal Generator from 50 0 MHz to 2 0 GHz in 50 MHz steps while observ ing the power meter readings Record the minimum and maximum output power levels in the following table Maximum power variation must be within 1 0 dB highest point to lowest point 24 Continue tuning the Signal Generator to 6 6 GHz in 100 MHz steps while observing the power meter readings Maximum power variation must be within 1 5dB Record the minimum and maximum output power levels in the following table 25 Continue tuning the Signal Generator to 12 8 GHz in 100 MHz steps while observ ing the power meter readings Maximum power variation must be within 2 0 dB Record the minimum and maximum output power levels in the following table 26 Continue tuning the Signal Generator to 18 6 GHz in 100 MHz steps while observ ing the power meter readings Maximum power variation must be within 2 5 dB Record the minimum and maximum output power levels in the following table HP 8673D only 27 Continue tuning the Signal Generator to 26 0 GHz in 100 MHz steps while observ ing the power meter readings Maximum power variation must be within 3 5 dB Record the minimum and maximum output power levels in the following table 4 7 Performance Tests ABBREVIATED PERFORMANCE TESTS OUTPUT L
227. easuring receiver The reading should be within 10 1 of 90 AM depth Record the reading Signal Generator Frequency 6 6 GHz 6 6 GHz 6 6 GHz 10 GHz 14 GHz HP 8673D only 18 6 GHz 22 GHz Local Oscillator Frequency 6 5 GHz 6 5 GHz 6 5 GHz 9 9 GHz 13 9 GHz 18 5 GHz 21 9 GHz Low Actual Limit Depth 10 kHz 10 kHz 10 kHz 79 9 High Limit 100 1 100 1 100 1 100 1 100 1 100 1 100 1 100 1 4 17 Performance Tests HP 8673C D ABBREVIATED PERFORMANCE TESTS EXTERNAL FM ACCURACY AND METER ACCURACY Description Equipment Procedure 4 18 The Signal Generator is frequency modulated by an external source The output of the Signal Generator is then mixed with a local oscillator to produce a modulated 500 MHz IF signal A measuring receiver measures the FM characteristics of the IF signal Local Oscillator ccc cece eens HP 8340A Measuring Receiver ee HP 8902A Test Oscillator cas canes Gnceaees HP 8116A Digital Voltmeter cece eee HP 3456A Frequency Counter cce eee HP 5343A EG L a D EE a RHG DMS1 26 HP 8673C D SYNTHESIZED SIGNAL GENERATOR LOCAL OSCILLATOR TEST OSCILLATOR OUTPUT RIO 7 RF OUTPUT OUTPUT MIXER RE SL LO BNC TEE re DIGITAL VOLTMETER MEASURING RECEIVER INPUT Figure 4 9 External FM Accuracy and Meter Accuracy Test Setup Sensitivity and Meter Accuracy 1 Connect equipment as shown in Figure 4 9
228. eck that the SRQ value is 1 indicating the Signal Generator issued the Require Response Service message Status Bit Message Note This check determines whether or not the Signal Generator sends the Status Bit message This check can be performed in either local or remote mode If the Signal Generator s SRQ annunciator is off perform the first part of the Require Service Message check before beginning this check If a series 200 300 controller is used two short programs are required to perform this check 3 28 HP 86738C D Operation OPERATOR S CHECKS HP IB Functional Checks contd Status Bit Message Cont d Description Series 200 300 HP 85B BASIC Configure the Signal Generator to 10 PPOLL CONFIGURE SEND 7 LISTEN 19 respond to a parallel poll on HP IB 719 10 CMD 5 SCG 10 data line DIO3 Place the Signal Generator in 20 V PPOLL 7 V PPOLMK 7 parallel poll mode causing it to send the Status Bit message and store the result in variable V Display the value of V 30 DISP V 40 END Operator s Check that the SRQ annunciator is on and that the response to the parallel poll is 4 Response indicating that the Signal Generator issued the Status Bit message Description Series 200 300 HP 85B BASIC Unconfigure the Signal Generator 10 PPOLL SEND 7 LISTEN 19 from responding to a parallel poll UNCONFIGURE 719 CMD 5 SCG 18 Place the Signal Generator in 20 V PPOLL 7 V PPOLL 7 parallel poll
229. ect IF frequency Offset frequency is only available on system compatible instruments To determine if a specific Signal Generator is system compatible see paragraph 3 2 System Compatibility Once the desired positive or negative offset is entered the frequency displayed by the Signal Generator will be different from the actual RF frequency by the frequency offset Entering or programming frequencies with frequency offset enabled will automatically calculate the required output frequency according to the frequency offset To set a frequency display offset 1 Press the blue shift key to access the shifted functions The shifted functions are printed in blue above the associated key 2 Press the OFFSET key if the displayed frequency is to be above the actual output frequency Otherwise press the OF FSET key if the displayed frequency is to be below the actual offset frequency 3 Enter the desired offset frequency using the numeric keypad If a mistake is made while entering the frequency press the backspace key until the incorrect digit disappears Continue entering the correct digits until the frequency displayed in the FREQUENCY MHz display is correct 4 Press the appropriate units key The frequency may be entered in GHz MHz or kHz Once the units key is pressed the displayed frequency will be adjusted to display MHz and the offset frequency will be displayed until the units key is released Once the units key is released
230. ect the shipping container for damage If the shipping container or cushioning material is damaged it should be kept until the contents of the shipment have been checked for completeness and the instrument has been checked mechani cally and electrically The contents of the ship ment should be as shown in Figure 1 1 Procedures for checking electrical performance are given in Section IV If the contents are incomplete if there is mechanical damage or defect or if the instru ment does not pass the electrical performance test notify the nearest Hewlett Packard office If the shipping container is damaged or the cushioning material shows signs of stress notify the carrier as well as the Hewlett Packard office Keep the shipping materials for the carrier s inspection 2 3 PREPARATION FOR USE 2 4 Front Handles Two front handles are supplied with the Signal Generator These front handles are required for mechanical support when the Signal Generator is not rack mounted Install the front handles using the instructions included in the front handle package CAUTION The front handles are packed with both English and metric screws Use of the wrong screw will result in damage to the mounting screw threads which will cause the front handles to fit improperly To determine if your Signal Generator requires English or metric screws remove the plastic trim strip fromits channel at the top front of the Signal Generator Look in the rig
231. ector to maintain a constant level at the point where the signal is detected External ALC also enables external devices such as amplifiers mixers and other specialized devices to be inserted into the RF signal path with control of the final output level by the Signal Generator In applications where the external signal path has frequency dependent losses and or gains the RF signal at the end of the signal path will no longer be a constant amplitude over the Signal Generator s frequency range For example if a cable is used that has a constant 0 5 dB GHz loss a level error of 5 dB would occur after a 10 GHz frequency change The signal at the RF output connector of the Signal Generator has not changed but an extra 5 dB of attenuation is introduced in the signal path when the output frequency is changed The detection of the external signal level can be done using one of several methods The _ simplest method uses a crystal detector or Schottky diode which has an output voltage that is proportional to the detected power square law A positive or negative crystal detector may be used with equal results since the Signal Generator does an absolute value conversion on the feedback signal External ALC using a diode crystal detector or Schottky diode has the advantage of fast settling time In addition diode leveling is simpler and less expensive than other methods The detector however must be operating in the square law region for cali br
232. ed with the Signal Genera tor are shown in Figure 1 1 a Two power cables are supplied in several con figurations depending on the destination of the original shipment Refer to Power Cables in Sec tion H of this manual HP 8678C D ACCESSORIES SUPPLIED cont d b Additional fuses are shipped only with instru ments that are factory configured for 100 120 Vac operation These fuses have rating of 1 5A and 2 0A They are for reconfiguring the instrument for 220 240 Vac operation c Two adapters are provided APC 3 5 F to TYP N P HP Part No 1250 1745 and APC 3 5 F F HP Part No 1250 1749 1 10 EQUIPMENT REQUIRED BUT NOT SUPPLIED For Option 002 instruments which lack an inter nal frequency standard an external reference must be used The performance of the external reference should at least match the specifications of the internal reference oscillator In particular the frequency should be within 50 Hz of 10 MHz When using an external oscillator microphon ically generated or line related spurious signals may increase SSB phase noise may also be de graded at some offsets from the carrier An external signal source is required if amplitude frequency or pulse modulation is desired For AM the source should have a variable output of 0 to 1V peak into 6000 frequency rates up to 100 kHz For FM the source should have a variable output of 0 to 1V peak into 500 frequency rates up to 10 MHz and distortion of
233. een the unit under test and this instrument prior to energizing either unit Whenever it is likely that the protection has been impaired the instrument must be made inoperative and be secured against any unintended operation If this instrument is to be energized via an auto transformer for voltage reduc tion make sure the common terminal is connected to neutral that is the grounded side of the mains supply Servicing instruction are for use by service trained personnel only To avoid dangerous electric shock do not perform any servicing unless qualified to do so Adjustments described in the manual are performed with power supplied to the instrument while protective covers are removed Energy available at many points may if contacted result in personal injury Capacitors inside the instrument may still be charged even if the instrument has been disconnected from its source of supply For continued protection against fire hazard replace the line fuse s only with 250V fuse s of the same current rating and type for example normal blow time delay etc Do not use repaired fuses or short circuited fuseholders SAFETY SYMBOLS Instruction manual symbol the product will be marked with this symbol when it is necessary for the user to refer to the instruc tion manual see Table of Contents for page references 5 Indicates hazardous voltages 2 Indicates earth ground terminal The WARNING sign d
234. el modulation modes and most other functions can be remotely programmed via HP IB Long term frequency stability is dependent on the time base either an internal or external reference oscillator The internal crystal reference oscillator operates at 10 MHz while an external oscillator may operate at 5 or 10 MHz The output of the 1 3 General Information DESCRIPTION cont d Signal Generator is exceptionally flat due to the action of the internal automatic leveling control ALC loop External drive signals are required for all modula tion modes AM depth and FM deviation vary lin early with the applied external voltage Full scale modulation is attained with a 1 0 volt peak signal Pulse modulation is compatible with TTL levels Two ranges of AM depth can be selected 30 and 100 The front panel meter can be used to set AM depth Specified AM rates are from 20 Hz to 100 kHz Six ranges of FM deviation are selectable 0 03 0 1 0 3 1 3 and 10 MHz FM peak deviation can be set using the front panel meter At output frequencies below 6 6 GHz peak deviation is limited to 10 MHz or five times the modulation frequency whichever is lower From 6 6 to 12 8 GHz peak deviation is limited to the lesser of 10 MHz or ten times the modulation frequency from 12 3 to 18 6 GHz the lesser of 10 MHz or fifteen times the modulation frequency from 18 6 to 26 0 GHz the lesser of 10 MHz or twenty times the modulation frequency Usable
235. el settings 1 14 Output Level dBm PULSE MODULATION ON OFF Ratio gt 90 dB 6 6 to 26 0 GHz Pulse Width Pulse widths from 100 ns down to 25 ns are possible with degraded peak power level accuracy relative to CW Pulse Input Normal Mode gt 3V on lt 0 5V off Complement Mode lt 0 5V on gt 3V off Impedance 500 nominal Damage Level For source gt 500 it is gt 6YV For source lt 500 it is gt 6V or more negative than 0 5V Pulse Width Compression lt 35 ns Maximum Delay Time 150 ns HP 8678C D General Information Table 1 2 Supplemental Characteristics 3 of 3 AMPLITUDE MODULATION FREQUENCY MODULATION Frequency Response Relative to a 1 kHz Rate 0 25 dB Rates 3 dB bandwidth 100 Hz to 10 MHz 30 and 100 100 Hz 10 kHz kHz V ranges 1 kHz to 10 MHz 300kHz V and 1 3 and 10 MHz V ranges Distortion Depth Percentage D g e D Won D g O 5 _ S ss QO i Rate kHz fc 0 01 to lt 16 0 GHz Carrier Level 0 dBm 50 75 Modulation Rate kHz Typical HP 8673C D FM Distortion versus modulation rate DIGITAL SWEEP Rear Panel BNC Sweep Connections Sweep Out 0 to 10V ramp start to stop maximum level adjustable between 4 and 12V Sweep Reference 0 5 V GHz ramp 18V maximum Z Axis Blanking Markers Tone Marker Output Penlift D O end C p O L t 00 LL can sheet Q D Rate kHz fc 16 0 to 26 0 GHz
236. el status annunciators Although pulse modulation is not monitored at the RF OUTPUT connector the status annuncia tors give a high degree of confidence that pulse modulation is functionally working 42 Press RCL 0 Set Output Level RANGE to 0 dB and Output Level VERNIER to 0 dBm 43 Press the PULSE COMPL key The UNLEVELED status annunciator should remain off 44 Press the PULSE NORM key Verify that the UNLEVELED status annunciator turns on Press PULSE OFF and verify that UNLEVELED status annunciator now turns off 45 Connect the pulse generator and oscilloscope to the Signal Generator as shown in Figure 3 10 HP 8673C D SYNTHESIZED SIGNAL GENERATOR PULSE Sls GENERATOR OSCILLOSCOPE TRIGGER OUTPUT EXT TRIGGER Figure 3 10 Pulse Modulation Functional Check Setup 3 22 HP 8673C D Operation OPERATOR S CHECKS nnn Basic Functional Checks contd Procedure 46 cont d 47 48 49 50 ol 52 53 Set the oscilloscope to 50 ohm input impedance and external horizontal trigger Set the pulse generator for a 150 ns pulse width at one pulse per microsecond i MHz On the pulse generator adjust the pulse amplitude for a pulse height of approx imately 3V peak With PULSE OFF selected CW mode note the indicated power level on the Signal Generator s meter should be 0 dBm Press PULSE NORM and PULSE COMPL keys while observing any change in indicated output power level
237. enerator The Negative Blanking line produces 5V for Z axis blanking of CRT displays that require a negative blanking voltage Table 3 2 AUX Connector Functions a T INPUTS 1 2 Recall Next G FREQ INCREMENT Up 5 Trigger Single Sweep 6 Service 7 Stop Sweep 4 FREQ INCREMENT Down 12 No Display OUTPUTS 8 Negative Blanking 9 Trigger Recall 1 Recalls the contents of internal storage register 1 Sequential recall of internal storage registers 2 through 9 Same as FREQ INCREMENT Up key Same as FREQ INCREMENT Down key Same as SINGLE key Same as internal service switch on A2A2 Key Code Assembly Refer to Section VIII Service Stops sweep Sweep resumes when this line goes high Blanks FREQUENCY MHz display when this pin is grounded and the existing display changes 5V for blanking One pulse when the Signal Generator has made a frequency change that may cause loss of phase lock to an instrument tracking the Signal Generator 10 End of Sweep One pulse at end of each sweep 3 31 Operation 3 23 REMOTE OPERATION qi cp The Signal Generator can be operated through the Hewlett Packard Interface Bus HP IB Bus com patibility programming and data formats are described in the following paragraphs All front panel functions except that of the LINE switches and the backspace key and remote only functions are programmable via HP IB A quick test of the Signal Gene
238. enerator rear panel FREQ STANDARD INT EXT switch to EXT Remove the FREQ STANDARD jumper and connect A3J10 to the 10 MHz frequency standard output of the fre quency counter With the Signal Generator and the frequency counter sharing a common timebase the frequency counter should agree with the Signal Generator FREQUENCY MHz display 1 count with any selected frequency counter resolution 2 Select 1 kHz display resolution on the frequency counter 3 Press RCL0O on the Signal Generator Tune the Signal Generator to 50 MHz at an output level of 0 dBm 4 Verify that the frequency counter reads 50 000 MHz 1 count due to the accuracy of the frequency counter 49 999 MHz 50 001 MHz 5 Tune the Signal Generator to each of the frequencies listed in the following table Verify that the NOT LOCKED annunciator remains off at each frequency and that the frequency counter agrees with the Signal Generator FREQUENCY MHz display 1 count Record the readings NOTE Fast tuning of the frequency may cause the NOT LOCKED annunciator to flash on momentarily This is normal and does not indicate a malfunction 4 3 Performance Tests ABBREVIATED PERFORMANCE TESTS HP 8673C D FREQUENCY RANGE AND RESOLUTION TEST cont d Procedure cont d Frequency MHz 2 090 000 2 280 001 2 471 112 2 662 223 2 853 334 3 044 445 3 235 556 3 426 667 3 617 778 3 808 889 3 999 999 4 180 000 4 370 000 4 560 000 4 750 000 4 940
239. enotes a vez gu hazard It calls attention to a procedure practice or the like which if not correctly performed or adhered to could result in per sonal injury Do not proceed be yond a WARNING sign until the indicated conditions are fully understood and met The CAUTION sign denotes a hazard It calls attention to an operating procedure practice or the like which ifnot correctly per formed or adhered to could result in damage to or destruction of part or all of the product Do not proceed beyond a CAUTION sign until the indicated conditions are fully understood and met CAUTION 1 1 General Information HP 8673C D porao SYNTHESES R aar nane APC 3 5 F to TYPE N F ADAPTER LINE POWER CABLE APC 3 5 F F ADAPTER angen G ves S G OPTION 913 G OPTION 908 RACK FLANGE KIT EXTENDER BOARDS RACK FLANGE KIT FOR INSTRUMENTS WITH HANDLES Figure 1 1 HP 8673C D with Accessories Supplied and Options 908 and 913 HP 8673D shown HP 8673C D General Information SECTION GENERAL INFORMATION 1 1 INTRODUCTION The HP 8678C D operating and service informa tion consists of an Operating Manual and a Service Manual These two volumes contain all the infor mation required to install operate test adjust and service the Hewlett Packard Model 86738C D Syn thesized Signal Generator Figure 1 1 shows an HP 8673D Signal Generator with all of its exter nally supplied accesso
240. entered marker number is not between 1 and 5 HP 8673C D Description Local Procedure Operation Detailed Operating Instructions Master Slave Sweep Master Slave Sweep enables two Signal Generators to track each other while sweep ing The output frequencies of the Signal Generators can be identical or offset by a fixed amount The Master Signal Generator controls stepping the the sweep of the Slave In Master Slave mode two Signal Generators are interconnected through the Hewlett Packard Interface Bus HP IB The Master unit is set to HP IB address 50 and the Slave is set to HP IB address 40 The sweep start and stop frequencies are set to identi cal frequencies on both the master and slave instruments Desired offset is then entered on the Slave unit by adjusting the sweep center frequency The Master unit is swept using any of the three sweep modes The Slave unit will track the Master unit offset in frequency by the difference in sweep center frequencies To set two Signal Generators to Master Slave sweep mode 1 Interconnect the two Signal Generators using an HP IB cable 2 Press RCL 0 on both units 3 Designate one Signal Generator as the Master unit by setting the HP IB address to 50 The HP IB address can be set from the front panel by keying in 50 pressing the STO key then pressing the LOCAL key When the HP IB address is set to 50 the TLK annunciator on the front panel will light to indicate that the Signal Generator
241. ep conta The BYPASS mode and SYSTEM leveling cannot be selected for frequencies below 2 GHz This error is only defined for system compatible instruments See paragraph 3 2 System Compatibility for more information The sweep stop frequency has been set equal to the start frequency No sweep will occur when a sweep mode is selected Indicates that the desired sweep start frequency is below the frequency range of the instrument This error may be displayed when the SWEEP FREQ STOP key is pressed if tuning the instrument placed start frequency below the frequency range of the Signal Generator Indicates that the desired sweep stop frequency is above the frequency range of the instrument This error may be displayed when the SWEEP FREQ STOP key is pressed if tuning the instrument placed the stop frequency above the frequency range of the Signal Generator Number of steps were adjusted to give even step size This ensures that the full sweep span is covered by adjusting the number of steps For example if the number of steps is set to 100 and the stop frequency is 2000 010 MHz setting the start fre quency to 2 GHz will automatically adjust the number of steps to 10 to accommo date the minimum frequency resolution of 1 kHz Auto Peak malfunction This indicates that the instrument may require service Operation HP 86738C D Detailed Operating Instructions Description Local Procedure 3 156 System Automatic Level Control
242. eps Entering a sweep step size will recalculate the number of steps by dividing the sweep frequency span by the entered sweep step size The sweep step size will be adjusted until the number of steps is an integer number between 1 and 9999 steps The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program is used to set the Signal Generator sweep step size to the frequency speci fied by the variable Expected The desired value must bein MHz and should be between 1 kHz and the maximum frequency of the Signal Generator 10 SUB Step_size Err Expected 20 OUTPUT 719 USING 2A MG Clear message from 8673 30 ENTER 719 USING 2A Message l to clear any old messages 40 OUTPUT 719 USING 2A 5D DDD 2A SP Expected MZ Set size 50 OUTPUT 719 USING 2A MG Get any error message 60 ENTER 719 USING 2A Message 70 SELECT VAL Message 80 CASE 1 90 Err 1 100 DISP WARNING Sweep step size is out of range 110 CASE ELSE 120 Err 0 130 END SELECT 140 150 SUBEND The following message numbers may be displayed when setting the sweep step size Each message is explained as it pertains to setting sweep step size For amore complete description of the messages see the MESSAGES detailed operating instructions 05 The entered sweep step size is not within the capability of the Signal Generator 14 The step size is too small for the current frequency span T
243. equencies the tuning limits can be set to cover the band of interest which allows the user to tune the frequency without having to watch the Signal Generator display to determine when the frequency is outside of the selected band There are four rear panel connectors that are used for sweep coordinating signals SWP OUT provides a signal that is 0 volts at the beginning of a sweep and 10 volts at the end of the sweep regardless of the sweep width The output impedance is nominally 100 kilohms The TONE MKR connector provides a 5 kHz signal when an active marker frequency is generated This signal can be connected to the AM IN connector on the front panel to provide AM markers on the external display Nominal impedance of the TONE MKRis 600 ohms The BLANKING MARKER output provides a 5 volt signal at the beginning of each frequency change for blanking an external display The blanking function is used to eliminate the display of switching transients Once the frequency has settled the signal returns to 0 volts unless the new frequency is an active marker frequency If the frequency is an active marker frequency the signal is set to 5 volts to provide a Z axis input for intensifying the display at the marker sweep point The PENLIFT connector provides control for an external X Y recorder and is only active during the single sweep mode A TTL logic high is used to raise the pen anda TTL logic low is used to lower the pen The pen is only lowere
244. equencies that can be set are 15 999999 GHz 5 333333X3 and 16 000002 GHz 5 333334X3 Note that the roundoff error is only 1 kHz if 15 999999 GHz is programmed instead of 16 GHz For applications that require fastest execution the SOURCE SETTLED bit of the status byte can be used Once the bit is set after a frequency has been programmed the output is valid and the program may continue If the frequency is programmed and the status byte is not checked the program should wait at least the frequency switching speed time before assuming the output valid If the status byte is to be used to monitor settling the program string that sets the frequency should start with the program code CS This will clear any previous setting of the SOURCE SETTLED bit to avoid an incorrect indication The Signal Generator has several frequencies where mechanical switches are actuated to change the internal microwave signal path To avoid excessive mechanical wear on the switches due to repetitive sweeps only a single sweep is allowed that crosses a switch point in Auto Sweep mode Single sweep is not affected by this restriction since single sweep will only cross the switch points once Manual Sweep mode is also not restricted since the operator can hear the switch and react to the number of crossings A summary of the switch points is shown below See AUTO SWEEP MODE for more information about sweep limitations and ways to expand sweep ranges 3 133 Operation HP
245. equency Preferred Program Code Due to the use of frequency multiplication to generate frequencies above 6 6 GHz the frequency sometimes cannot be set precisely to a desired value Frequencies below 6 6 GHz can be set to the nearest 1 kHz All frequencies between 6 6 and 12 3 GHz can be set within 2 kHz of the desired value Frequencies between 12 3 and 18 6 GHz can be set within 3 kHz of the desired value and frequencies between 18 6 and 26 5 GHz can be set within 4 kHz of the desired frequency However with careful selection of fre quency the roundoff error can be reduced to 1 kHz below 18 6 GHz and 2 kHz for frequencies between 18 6 and 26 5 GHz When the Signal Generator is programmed to a frequency that cannot be set exactly due to frequency resolution a random roundoff occurs To prevent this the remote program should perform a calculation to determine whether the frequency can be set exactly and adjust the desired frequency accordingly To determine whether a frequency can be set to a given value divide the desired frequency in kHz by two if it is between 6 6 and 12 3 GHz by three if it is between 12 3 and 18 6 GHz or by four if it is above 18 6 GHz If the result is a whole number no remainder the frequency can be set to the desired value For example 16 GHz divided by three it is between 12 3 and 18 6 GHz is 5 333333 33 kHz Since the div idend is not a whole number this frequency cannot be set exactly The nearest fr
246. equency of 15 GHz The minimum tuning increment at 15 GHz is 3 kHz This means that the sweep step size can be 9 kHz or 12 kHz for exact step sizes To obtain a sweep step size of 10 kHz the Signal Generator will step by 9 kHz 9kHz 12 kHz and then repeat the sequence The average step size is 10 kHz even though the sweep does not execute exactly 10 kHz steps If the step size is reduced to 1 kHz the Signal Generator will step by 0 kHz 0 kHz and then 3 kHz for a 1 kHz average step size in the 3 kHz resolution frequency band Sweeps from a higher frequency to a lower frequency can be accomplished by setting the start frequency higher than the stop frequency This combination results in a negative frequency span as indicated when the frequency span is displayed Negative frequency spans can only be entered by setting the start frequency higher than the stop frequency The tuning controls will work as with a positive span but the remote program code IF will always produce a sweep step toward the stop frequency An Auto Peak operation is performed whenever the RF output frequency is more than 50 MHz from the frequency at which the last Auto Peak operation was performed The Auto Peak operation optimizes the Signal Generator performance at the current frequency The Auto Peak operation produces small changes in the RF output level as the peaking is performed For applications requiring fastest sweeps Auto Peak may be disabled However with Auto Peak di
247. er than 61 94 dB below the carrier lt 61 94 dBc Record the measured and actual level Measured dD Correction 16 06 dB Actual level _ dd Bee Tune the Signal Generator to 6600 MHz Tune the local oscillator to 6599 800 MHz Observe the noise level 1 kHz from the carrier The displayed level should be greater than 61 94 dB below the carrier lt 61 94 dBc Record the measured and actual level Measured _ dd Bee Correction 16 06 dB Actual level _ Ss d Bee Tune the Signal Generator to 12 300 MHz Tune the local oscillator to 12 299 800 MHz Observe the noise level 1 kHz from the carrier The displayed level should be greater than 55 94 dB below the carrier lt 55 94 dBc Record the measured and actual level Measured _ Ss dBe Correction 16 06 dB Actual level ss dd Be Tune the Signal Generator to 18 600 MHz Tune the local oscillator to 18 599 800 MHz HP 8673C D Performance Tests PERFORMANCE TESTS SINGLE SIDEBAND PHASE NOISE TEST cont d Procedure 35 Observe the noise level 1 kHz from the carrier The displayed level should be greater cont d than 51 94 dB below the carrier lt 51 94 dBc Record the measured and actual level Measured __ _ dBc Correction 16 06 dB Actual level 3s _ S dBc HP 8673D only 36 Tune the Signal Generator to 26 000 MHz 37 Tune the local oscillator to 25 999 800 MHz 38 Observe the noise level 1 kHz from the carrier The displayed level should be grea
248. er the bits must be enabled before a service request will be generated To enable a bit the corresponding bit of the Request Mask must be set to a one For example to generate a service request when the END OF SWEEP bit is set bit five of the Request Mask must be set to a logical one true The program string required to set bit 5 is RM16 since bit 5 has a weight of 16 see the status byte in Comments When the Signal Generator is first turned on the Request Mask is cleared so that a service request will not be generated The Request Mask value can be read by the controller so bits can be added or cleared from the present values The Request Maskis cleared by an HP IB clear but not by an instrument preset When a service request is generated whenever the RQS bitis set true the status byteis latched so the first cause of the service request can be identified Reading the stored status byte can only be done using a serial poll Reading the status byte using the output status program code OS will read the current status only Once the stored status byte is read the status byte is updated so a subsequent service request is not lost If more than one bit is enabled to generate a service request and more than one bitis set before the serial poll the first serial poll will read the status byte associated with the first service request Once the poll is completed another service request will be generated due to the one or more other bits tha
249. er the start and stop frequency or the center frequency and frequency span Setting start and stop frequency will begin the sweep at the start frequency and end at the stop frequency Setting the center frequency and frequency span will start the sweep at one half the frequency span below the center frequency and end the sweep at one half the frequency span above the center frequency Setting the CW frequency when sweep is off will also reset the sweep center frequency to the same value Setting the center frequency or frequency span will automatically recalculate the appropriate sweep start and stop frequencies Resetting the sweep start or stop frequency will reset the sweep center frequency if in sweep mode or the CW frequency if sweep is off The frequency span will be recalculated whether sweep is on or off The sweep center frequency or CW frequency will be reset to be halfway between the start and stop frequencies The sweep start frequency can be set to any valid Signal Generator frequency In addition if the start frequency is set above the stop frequency single and auto sweep modes will still sweep from the start to the stop frequency Manual sweep will start at the lower absolute frequency and move toward the higher absolute frequency To set the Signal Generator to a specific sweep start frequency 1 Press the SWEEP FREQ START key to indicate that the next entry will be for sweep start frequency 2 Enter the desired frequency usin
250. ere are four rear panel connectors that are used for sweep coordinating signals SWP OUT provides a signal that is 0 volts at the beginning of a sweep and 10 volts at the end of the sweep regardless of the sweep width The output impedance is nominally 100 kQ The TONE MKR connector provides a5 kHz signal when an active marker frequency is generated This signal can be connected to the AM IN connector on the front panel to provide AM markers on the external display Nominal impedance of the TONE MKRis 600 ohms The BLANKING MARKER output provides a 5 volt signal at the beginning of each frequency change for blanking an external display The blanking function is used to eliminate the display of switching transients Once the frequency has settled the signal returns to 0 volts unless the new frequency is an active marker frequency Ifthe frequency is an active marker frequency the signal is set to 5 volts to provide a Z axis input for intensifying the display at the marker sweep point The PEN LIFT connector provides control for an external X Y recorder A TTL logic high is used to raise the pen and a TTL logic low is used to lower the pen The pen is only lowered in single sweep and there is a 100 millisecond sweep delay for the pen to raise or lower To set the Signal Generator for automatic sweeping 1 Set the desired sweep parameters 2 Press the AUTO SWEEP MODE key to activate automatic sweep mode The key indicator will light and the
251. error has occurred during the Auto Peak operation This message indicates that service may be required HP 8673C D Description Local Procedure Operation Detailed Operating Instructions Single Sweep Mode The Signal Generator performs a digital sweep by stepping the RF output frequency in discrete steps from the start frequency to the stop frequency The number of steps that the Signal Generator produces between the start and stop frequency is controlled by the number of steps or the sweep step size parameters The time that the Signal Generator remains at each step after switching frequencies is controlled by the dwell time parameter The Signal Generator has three sweep modes to accommodate a variety of applications Auto sweep mode is used when a repetitive sweep is required Auto sweep mode will step the RF output frequency from the start frequency to the stop frequency and then repeat the sweep until the sweep is turned off or a band crossing is encountered Single sweep mode will step the RF output frequency from the start frequency to the stop frequency once and then stop This mode is useful when a single sweep is required for a measuring device to store results Control signals are provided at the rear panel of the Signal Generator for control of X Y recorders and external displays Manual sweep provides a convenient method to limit the tuning range of the frequency tuning controls In applications requiring a single band of fr
252. ers when the value of START STOP AF DWELL STEP or any Marker changes The Signal Generator can send a Require Service message in either the local or remote mode The Signal Generator sends a Require Service message by setting the Service Request SRQ bus line true The SRQ annunciator on the front panel turns on when the Require Service message is being sent The Require Service message is cleared after the Output Status function or the Clear Sta tus CS program code has been executed by the controller Request Mask The Request Mask functions within the Status Byte It determines which bits can set the RQS bit true see Figure 3 11 and consequently set the SRQ bus line true 3 40 HP 8673C D The Request Mask is set by the program code 1 followed by an 8 bit byte a Data Message The value of the byte is determined by summing the weight of each bit to be checked Each bit if true enables a corresponding condition to set the RQS bit true This message is executed immediately and does not require an End of String message to be sent At turn on the Request Mask is cleared that is set to 0 Sending the Request Mask Value a Data Message After receiving an OR program code Output Request Mask and when addressed to talk the Signal Generator will send a single binary word 8 bits that describes the present state of the mask The bit pattern can be interpreted with the infor mation in Figure 3 11 NOTE This
253. es HP 8673C D abin mnan Sa 7 ae ca TRE to POO L ee Sa 22505 EPE S555682 E 2 25355 25296 rey LE HP IB Connector Connects the Signal Generator to the Hewlett Packard Interface Bus for remote operation 2 FREQ REF BNC female connector Output impedance is 1009 nominal Provides a 0 5 V GHz voltage that is always on even when sweep is off SWP OUT BNC female connector Output impedance is 100Q nominal Provides a 0 to 10V ramp from start to stop An internal adjustment can set the slope of the ramp from 0 to between 4 and 12V TONE MKR BNC female connector Output impedance is 600Q nominal 5 kHz sine wave Can be connected to front pane AM IN to provide AM markers 8 PEN LIFT BNC female connector TTL high lifts pen TTL iow lowers pen 100 ms delay to lift or lower pen in single sweep mode O RF OUT A3U6 For Options 004 and 005 only 50Q APC 3 5 male output connector SZ 10 MHz OUT A338 0 dBm nominal into 500 can be used as an external timebase FREQ STANDARD Output A3U9 10 MHz into 500 at 7 dBm nominal from the internal frequency standard except when INT EXT switch is in the EXT position S Jumper A3W3 Normally connects the Internal Fre quency Standard Output A3J9 to the External Frequency Standard Input A3J10 FREQ STANDARD Input A3J10 Normally connected by A3W3 to A3J9 Also used to connect an external 6 9 a a ate Operation o ete siasa iaa D
254. escription Local Procedure Remote Procedure Program Codes Comments Operation Detailed Operating Instructions Normal and Bypass Modes NORMAL and BYPASS modes control the RF signal path within the Signal Generator The NORMAL mode provides additional filtering to the RF output signal by switching in one of four microwave filters for output frequencies above 2 GHz Frequencies between 2 and 3 5 GHz are filtered by a low pass filter to reduce the harmonics of the fundamental signal Another low pass filter is used to suppress harmonics for RF out put frequencies between 3 5 and 6 GHz A tracking bandpass YIG filter is used to reduce harmonics for RF output frequencies between 6 and 22 GHz For frequencies between 6 6 and 22 GHz the tracking filter is also used to suppress the fundamental feedthrough of the frequency multiplication process A high pass filter is switched in for frequencies above 22 GHz to reduce subharmonics Harmonics of the RF output above 22 GHz are not a problem due to the inherent low pass characteristics of the microwave components BYPASS mode is used to prevent the filters from being switched in This mode can be used to increase maximum available power and to eliminate mechanical switchings during sweep modes BYPASS mode provides higher RF output power at the expense of increased harmonic and subharmonic levels If the NORMAL indicator is lighted on the lower part of the front panel the Signal Gener
255. essage that is bus lines EOI true and ATN false The at sign acts as an EOS when the Signal Generator is in the Deferred Execution mode Valid Characters The ASCII characters used for program strings are A Z a z 0 9 LF The alpha program codes can be either upper or lower case since the Signal Generator will accept either type they can be interchanged Spaces unnecessary signs leading zeros and car riage returns CR are ignored However if a space or other such character were inserted between 2 characters of a program code the program code would be invalid and any remaining characters in a string might be misinterpreted by the Signal Generator After receiving an invalid program code the Signal Generator requires a valid pro gram code before it will respond to numeric entries immediate Execution Mode ASCII characters can be accepted in the Deferred or Immediate execu tion modes Immediate Execution is the default mode at turn on It can be set if necessary by sending the program code 3 In this mode the Signal Generator produces an End of String EOS message at the end of each character and does not require one from the controller The Signal Gener ator processes each character before accepting the next one Therefore the Immediate Execution mode does slow down overall data transfer How ever the Signal Generator can switch faster after 3 36 HP 8673C D the final EOS message than it
256. et the Signal Generator to the levels shown in the table below Tune the Signal Generator s output frequency as shown for each level The local oscillator should track the Signal Generator with a 70 MHz offset Measure rise time fall time over shoot and ringing at each frequency Rise and fall times should be less than 40 ns Overshoot and ringing should be less than 30 at 6 6 and 6 7 GHz and less than 25 at 12 3 GHz Record the results in the following table FALL Overshoot ns and Ringing OUTPUT LEVEL FREQUENCY Range verner NR 10dB 2 dBm 6600 002 10 dB 2 dBm 6700 002 10dB 2dBm 12 290 002 0dB 0dBm 6600 002 0 dB 0 dBm 6700 002 0 dB 0dBm 12 290 002 pi 0dB 10dBm 6600 002 0 dB 10dBm 6700 002 0daB 10dBm 1 12 290 002 Tune the Signal Generator from 6 6 to 12 3 GHz Ensure that rise time fall time overshoot and ringing are within the limits specified at output levels of 10 dBm 0 dBm and 8 dBm for all frequencies within this range Record the worst case results FREQUENCY OUTPUT LEVEL FALL Overshoot MHz RANGE VERNIER ns and Ringing peur remeron 5 5 1 dB Sat tee nest PH IT s T S P sl et nah RD EIR ob spake catered ee es es HP 8673C D Performance Tests PERFORMANCE TESTS PULSE RISE FALL TIME AND OVERSHOOT TEST cont d Procedure 16 Set the Signal Generator to the levels shown in the f
257. ete frequencies that are produced sequentially The minimum step size is limited to the minimum change in frequency that the Signal Generator can produce which is defined as the frequency resolution The sweep step size can change depending on the current frequency and the next frequency in the sweep HD 8673C D Comments contd Programming Example Error Messages Operation Detailed Operating Instructions Step Size Sweep conta The actual change in output frequency will not be uniform for some frequencies and may vary up to 2 kHz This is required to accommodate sweep step sizes that are not exact multiples of the frequency resolution The sweep steps averaged over several sweep points will be equal to the selected sweep step size An example of the averaging is defining a sweep step size of 10 kHz at a start frequency of 15 GHz The minimum tuning increment at 15 GHz is 3 kHz which means that the sweep step size can be 9 or 12 kHz for exact step sizes To obtain a sweep step size of 10 kHz the Signal Generator will step by 9 kHz 9 kHz 12 kHz and then will repeat the sequence The average step size is 10 kHz even though the sweep does not execute exactly 10 kHz steps If the step size is reduced to 1 kHz the Signal Generator will step by 0 kHz 0 kHz and then 3 kHz fora 1 kHz average step size When the sweep frequency span is changed the sweep step size is recalculated by dividing the entered span by the current number of st
258. etting sweep start frequency For a more complete description of the messages see the MESSAGES detailed operating instructions 01 Entered frequency is not within the range of the Signal Generator 10 The sweep start frequency has been set equal to the stop frequency No sweep will occur when a sweep mode is selected 11 Indicates that the current sweep start frequency is below the range of the Signal Generator This error may be displayed when the SWEEP FREQ START key is pressed if tuning the instrument placed the sweep start frequency below the frequency range of the Signal Generator 3 135 Operation HP 8678C D Detailed Operating Instructions Start Frequency Sweep conta Error 12 Indicates that the current sweep stop frequency is above the frequency range of the Messages Signal Generator This error may be displayed when the SWEEP FREQ STOP key cont d is pressed if tuning the instrument placed the sweep stop frequency above the frequency range of the Signal Generator 13 Number of steps were adjusted to give even step size This ensures that the full sweep span is covered by adjusting the number of steps For example if the number of steps is set to 100 and the stop frequency is 2000 010 MHz setting the start frequency to 2 GHz will automatically adjust the number of steps to 10 to accom modate the minimum frequency resolution of 1 kHz 90 Auto Peak malfunction This indicates that the instrument may require service 3
259. ey on the Master unit The Master and Slave units will be reset to their respective start frequencies The sweep modes of the Master unit AUTO MANUAL and SINGLE are controlled by the Master s front panel The Slave unit s MANUAL and SINGLE keys will always be lit no matter which mode the Master unit is operating in When using Master Slave sweep the 10 MHz frequency reference should be supplied by only one instrument This will improve the accuracy of the sweep and maintain phase coherent signals during the sweep Error The following messages may be displayed when using Master Slave sweep Messages 01 Entered frequency is not within the range of the Signal Generator 03 Invalid multiplier entry for system compatible instruments Error 03 is defined as BYPASS mode not functional below 2 GHz for non system compatible instru ments See paragraph 3 2 System Compatibility for more information about system compatibility 06 The BYPASS mode and SYSTEM leveling cannot be selected for frequencies below 2 GHz This error is only defined for system compatible instruments See paragraph 3 2 System Compatibility for more information 10 The sweep start frequency has been set equal to the stop frequency No sweep will occur when a sweep mode is selected 11 Indicates that the current sweep start frequency is below the range of the Signal Generator This error may be displayed when the SWEEP FREQ START key is pressed if tuning the in
260. f 70 MHz These resulting IF signals are amplified and viewed on an oscilloscope to determine pulse performance HP IB Controller HP 9836A or HP85B 82903 Local Oscillator HP 8340A Pulse Generator HP 8013B Oscilloscope ee ee eee HP 1980B Pre Amp Power Amp HP 8447F MIKEY Yo oe yeaa vie adini aa oes RHG DMS1 26 20 dB Attenuator HP 8493C Option 020 3 dB Attenuator HP 8491A Option 003 10 dB Attenuator HP 8491A Option 010 Mixer Mags teehee tes ante tree H HP 10514A 1 Connect the equipment as shown in Figure 4 27 Ensure that the HP 10514A mixer is used for this part of the test procedure NOTE Make sure there are no sharp bends in the cables and that all connec tions are tight Connect the LO port of the mixer directly to the output connector of the local oscillator Connect the 3 dB attenuator directly to the IF port of the mixer This will minimize distortion of the pulse shape and thus give more accurate measurements 2 Set the Signal Generator as follows FREQUENCY asccoasdauaas sexe veges 50 MHz OUTPUT LEVEL RANGE 10 dB OUTPUT LEVEL VERNIER 1dBm PULSE geass neare ee te eeu eres NORM HP 86738C D Performance Tests PERFORMANCE TESTS PULSE RISE FALL TIME AND OVERSHOOT TEST cont d Procedure contd HP B CONTROLLER HP 8673C D SYNTHESIZED SIGNAL GENERATOR Cre pone a
261. fied frequency range Above 6 6 GHz the programmed frequency may be rounded by the Signal Generator to be compatible with the 2 3 or 4 kHz resolution at the programmed frequency see Comments 3 131 Operation HP 86738C D Detailed Operating Instructions Remote Procedure cont d Example 3 132 start Frequency Sweep conra The format of the remote programming follows the front panel key sequence To program the sweep start frequency the program code FA is sent followed by the desired frequency and the units GZ MZ KZ or HZ If setting the new start frequency causes a change of the CW frequency normally the case the SOURCE SETTLED bit of the status byte can be monitored to determine when the new frequency has settled Once this bit is set the NOT LOCKED bitin the extended status byte may be checked to ensure that the instrument is working correctly The NOT LOCKED bit is not valid until after the SOURCE SETTLED bit has been set The current sweep start frequency can be read by the controller using the output active program code suffix To read the start frequency send the program codes FAOA and then read the start frequency The Signal Generator will send the frequency in fundamental Hz units If the frequency is read as a string the format will be the program code FA followed by the sweep start frequency in Hz and then the units terminator Hz To set the sweep start frequency to 16 232 334 MH
262. front panel CAL control until the ALC UNLEVELED annunciator is extinguished Reset the VERNIER for a 0 dBm indication on the Signal Gener ator s front panel LVL meter and then adjust the CAL control until the power meter indicates exactly 10 dBm 6 The output level can now be set by adjusting the VERNIER for the desired output level as read on the level meter Setting the range to 0 dB will reduce the output level by 10 dB However setting the range lower than 0 dB will not change the output level until the ALC goes unleveled due to insufficient output power to overcome the additional loss in the RF path Note that there are two ALC CAL controls on the front panel The control nearest the external ALC input is for calibrating the output level at frequencies above 2 GHz The lower CAL control is used to calibrate the output level for frequencies below 2 GHz If frequencies above and below 2 GHz are to be used the calibration of step 5 should be performed for each CAL control Remote 1 Perform the above steps 1 to 5 to calibrate the external ALC circuitry 2 Set the output level remotely by programming vernier settings between 10 and 3 dBm Changing the range will have the same affects as described in step 6 above Program Code Description External Power Meter Leveling Mode Using external power meter leveling mode has the advantages of high stability temperature compensation and high sensitivity The disadvantage of powe
263. g hidden parameters However front panel displays remain active and valid In remote the Signal Generator can be addressed to talk or listen When addressed to listen the Signal Gen erator automatically stops talking and responds to the following messages Data Trigger if con figured Clear SDC Remote Local Local Lock out and Abort When addressed to talk the Signal 3 32 HP 8678C D Generator automatically stops listening and sends one of the following messages Data Require Ser vice or Status Byte Whether addressed or not the Signal Generator responds to the Clear DCL Local Lockout Clear Lockout Set Local and Abort messages In addition the Signal Generator can issue the Require Service message and the Status Bit message Local to Remote Mode Changes The Signal Gen erator switches to remote operation upon receipt of the Remote message The Remote message has two parts They are a Remote enable bus control line REN set true b Device listen address received once while REN is true When the Signal Generator switches to remote the RMT annunciator on the front panel turns on With the exception of VERNIER which may change by less than 0 1 dB the Signal Generator s control settings remain unchanged with the Local to Remote transition 3 26 Local Mode Local Capability In local the Signal Generator s front panel controls are fully operational and the instrument responds to the Re
264. g in 2 26 5 GHz frequency range AUTO PEAK Key Maximizes power at the output frequency and optimizes pulse shape for pulse modulation a gt ALC CAL Control Same as in the 0 01 to lt 2 0 GHz frequency range CA BYPASS NORMAL key Used to switch the Signal Generator between BYPASS and NORMAL modes The HP 8673C D has RF filters for improving spectral purity in the NORMAL mode These filters are bypassed in the BYPASS mode For frequencies below 2 0 GHz the signal generator automatically switches to the NORMAL mode EXT ALC IN Connector BNC female connector that accepts positive or negative leveling signals froma diode detector power meter or system reference Figure 3 3 Output Level Features 3 9 Operation amp FREQUENCY Key Used as a prefix to the Data and Units keys to set a continuous wave CW frequency or center frequency for a AF sweep 2 FREQ INCR Key Used as a prefix to the Data and Units keys to set the step size for the FREQ INCREMENT W and e keys or the TUNE knob Pressing the FREQ INCR key recalls the current increment value to the FREQUENCY MHz display for as long as the key is depressed SHIFT Key Used as a prefix to obtain functions of certain keys Keys containing shifted functions are labeled with that function in blue amp ROS S8TG Key Normal operation RCL Used as a prefix to a numeric key a single difgit O 9 to iden tify the storage register to recall th
265. g the numeric keypad If a mistake is made while entering the frequency press the backspace key until the incorrect digit disappears Continue entering the correct digits until the frequency displayed in the FREQUENCY MHz display is correct 3 Press the appropriate units key The frequency can be entered in GHz MHz or kHz Once the units key is pressed the displayed frequency will be adjusted to display MHz and the sweep start frequency will be set The sweep start frequency will continue to be displayed until the units key is released The actual frequency displayed after releasing the units key will usually not be the entered frequency If sweep mode is off the displayed frequency will indicate the frequency halfway between the new start frequency and the stop frequency If auto sweep is on the sweep will be reset and then continue using the new start frequency If single sweep is on the sweep will be reset and the sweep will remain armed at the new start frequency If manual sweep is on the sweep frequency will be reset to the start frequency To check the current sweep start frequency press and hold the SWEEP FREQ START key The FREQUENCY MHz display will display the sweep start frequency as long as the key is held When any sweep mode is turned off the CW frequency will be set to halfway between the start and stop frequencies equal to the sweep center frequency The Signal Generator accepts any sweep start frequency within its speci
266. g this key displays the present STRT value in the FREQUENCY MHz display for as long as the key is depressed Shifted function MULT Used as a prefix to the Data and Units keys Invokes the multiplier mode of operation and allows entry of the frequency multi plication factor The entered multiplication factor affects all frequencies that is markers increments FM deviation CW sweep and center frequencies The multiplication effect on FM deviation is not indi cated on the FM meter L STOP Key Normal operation STOP Used as a prefix to the Data and Units keys to set the ending fre quency of a sweep Pressing this key displays the present STOP value in the FREQUENCY MHz display for as long as the key is depressed Shifted function OFFSET Used as a prefix to the Data and Units keys invokes the offset mode of frequency eniry and display Frequency entries will be dis played as entered but the actual instrument output frequency will be the offset amount BELOW the entered and displayed frequency 3 AF Key Normal operation AF Used as a prefix to the Data and Units keys to set sweep span Pressing this key displays the present span value in the FREQUENCY MHz display for as long as the key is depressed Center frequency of the spanis set with the FREQUENCY key Shifted function OFFSET Used as a prefix to the Data and Units keys Invokes the offset mode of frequency entry and display Frequency entries will be dis
267. ge and below lt 55 dBe 0 05 to lt 1 2 GHz lt 60 dBe 1 2 to 26 0 GHz Harmonics up to 26 GHz BYPASS mode output level vernier settings lt 0 dBm on 0 dBm range and below lt 45 dBc Subharmonics and Multiples Thereof BYPASS mode lt 30 dBc 0 05 to lt 18 6 GHz lt 20 dBe gt 18 6 to 26 0 GHz Single sideband Phase Noise 1 Hz BW CW mode 0 05 to 10 100 ik 10k 100k 1M 10M Offset From Carrier Hz Add 6 dB for 6 6 to 12 8 GHz 10 dB for 12 3 to 18 6 GHz and 12dB for 18 6 to 26 0 GHz 1 13 General Information HD 8673C D Table 1 2 Supplemental Characteristics 2 of 3 RF OUTPUT Gutput Level Switching Time to be within 1 dB of finai level with ne range change Operating Mode Output Level Switching Time CW lt 15 ms AM and Sweep lt 5 ms For power settings gt 0 dBm changes in frequency of several GHz in one step may require an addi tional AUTO PEAK operation to stabilize power at the desired level Spurious output oscillations may occur for output level settings above 8dBm External leveling device characteristics will deter mine output flatness absolute level accuracy and switching time in external leveling modes Impedance 50 ohms Source SWR lt 2 0 Output Level Accuracy m L Q 6 L 3 O oO lt P gt 03 zj 2 4 6 8 10 12 14 16 18 20 22 24 26 Output Frequency GHz Typical HP 8673C D output level accuracy at 0 70 and 100 dBm lev
268. given frequency For example with 15 dB of loss in the signal path the Signal Generator must compensate with at least 15 dB of additional RF output power With no internal attenuation 0 or 10 dB ranges the Signal Generator would have to supply 15 dBm for a leveled signal at 0 dBm Since the maximum RF output power is specified at less than 13 dBm the Signal Generator may not be able to supply the required power Using Signal Generator ranges of 10 to 90 dB add attenuation to the RF signal path These ranges are useful mainly when attempting to level low amplitude signals For example to level a signal with an amplitude of 50 dBm after a signal path with losses of 30 dB the attenuation can be set to 10 dB range 10 dB to place the Signal Generator at an RF output level of 10 dBm The internal circuitry generates RF levels of 10 dBm and higher before introducing attenuation to increase the dynamic range of the Signal Generator When selecting the proper range for external leveling the lowest and highest gain loss should be calculated The range is then set 10 dB higher than the level required to keep the internally generated RF level near 10 dBm The external ALC circuitry is used to adjust the Signal Generator s output level until the detected voltage at the external ALC input is correct Ifhigh harmonics or spurious signals are present in the signal that is being detected they will affect level flatness This is espe
269. h an output amplitude of 8 dBm 9 Set the spectrum analyzer controls so that the peak of the 40 kHz IF signalis at the top graticule line 10 Observe the noise level 30 Hz from the carrier The displayed level should be greater than 62 7 dB below the carrier lt 62 7 dBc Record the measured and actual level Measured dB Correction 1 3 dB Actual Level 00d Bee 11 Tune the Signal Generator to 12 300 MHz 4 36 HP 86738C D Performance Tests PERFORMANCE TESTS SINGLE SIDEBAND PHASE NOISE TEST contd Procedure 12 Tune the local oscillator to 12 299 960 MHz cont d 13 Observe the noise level 30 Hz from the carrier The displayed level should be greater than 56 7 dB below the carrier lt 56 7 dBc Record the measured and actual level Measured ____ BC Correction 1 3 dB Actual Level ___ dBc 14 Tune the Signal Generator to 18 600 MHz 15 Tune the local oscillator to 18 599 960 MHz 16 Observe the noise level 30 Hz from the carrier The displayed level should be greater than 52 7 dB below the carrier lt 52 7 dBc Record the measured and actual level Measured si Bice Correction 1 3 dB Actual Level _ Sd Ber HP 8673D only 17 Tune the Signal Generator to 26 000 MHz 18 Tune the local oscillator to 25 999 960 MHz 19 Observe the noise level 30 Hz from the carrier The displayed level should be greater than 50 7 dB below the carrier lt 50 7 dBc Record the measured a
270. hat sets the frequency should start with the program code CS This will clear any previous setting of the SOURCE SETTLED bit to avoid an incorrect indication The Signal Generator has several frequencies where mechanical switches are actuated to change the internal microwave signal path To avoid excessive mechanical wear on the switches due to repetitive sweeps only a single sweep is allowed that crosses a switch point in auto sweep mode Single sweep is not affected by this restriction since single sweep will only cross the switch points once Manual sweep mode is also not restricted since the operator can hear the switch and react to the number of crossings A summary of the switch points is shown below See AUTO SWEEP MODE for more information about sweep limitations and ways to expand sweep ranges HP 8678C D Comments contd Programming Example Operation Detailed Operating Instructions Stop Frequency Sweep conta Frequency Switch Point Description 2GHz The microwave signal path is switched for downconversion when switching from above 2 GHz to below 2 GHz 2 GHz A low pass filter is switched in to reduce harmonics 2 0 3 5 GHz 3 5 GHz A low pass filter is switched in at this frequency to reduce harmonics 3 5 6 0 GHz 6 0 GHz A tracking bandpass filter is switched in from 6 to 22 GHz 18 6 for the HP 8673C to reduce harmonics and subharmonics above 6 6 GHz 16 0 GHz An amplifier is switc
271. he FREQUENCY MHz display should show 2000 000 MHz Tune the frequency up by turning the TUNE knob clockwise Verify that the FREQUENCY MHz display changes in 20 MHz increments and stops at 4000 000 MHz Tune the frequency down to 2000 000 MHz by turning the TUNE knob counter clockwise Verify that the FREQUENCY MHz display changes in 20 MHz steps and stops at 2000 000 MHz Press the SWEEP OFF key and verify that the FREQUENCY MHz returns to 3000 000 MHz Press the SINGLE sweep key Verify that the key indicator turns on and the FREQUENCY display shows 2000 000 MHz Press the SINGLE sweep key again A single sweep should now be executed Verify that the FREQUENCY MHz display changes in 20 MHz steps very rapidly until 4000 000 MHz is reached The display then returns to the START frequency of 2000 000 MHz Press the SWEEP OFF key Verify that the FREQUENCY MHz display returns to 3000 000 MHz AM Check The front panel meter and UNLEVELED status annunciator are used as an indication of AM The meter monitors input signal level only rather than actual AM A modulation analyzer can be used to monitor the signal at the RF output connector for greater assurance of AM performance 3 20 HP 8673C D SYNTHESIZED TEST OSCILLATOR OSCILLOSCOPE B00 92 OUTPUT BNC TEE Figure 3 8 AM Functional Check Setup HP 8678C D Operation OPERATOR S CHECKS Basic Functional Checks cont d Procedure 32 Press RCL 0 to preset the S
272. he RF output level is read as a string To set the RF output level to 56 dBm Local 1 Press the ALC INT key to place the Signal Generator into internal ALC mode The process for setting the RF output level for external ALC modes is covered under the appropriate ALC mode 2 Set the RANGE to the lowest range that is less than 10 dB above the power or 50 dBm in this case 3 Adjust the VERNIER until the level meter indicates 6 dBm For the 50 dBm RANGE the VERNIER can adjust the output level from 60 to 47 dBm Remote The programming string for setting the RF output level is composed of a program code numeric data and the units terminator The RF output level may be programmed directly or the RANGE and VERNIER may be programmed separately To program the Signal Generator to a level of 56 dBm the possible program strings are LE 56DM or RA SODBVE 6DM In addition the program code could be AP or PL instead of LE The alpha characters can be sent as upper or lower case or even mixed upper and lower case The Signal Generator RF output level is valid once the SOURCE SETTLED bit of the status byte is set see Comments The units terminator could be DB or DM The Signal Generator accepts either terminator for all power related settings i Description Output Level Range RF Output Level RF Output level RF Output level Program Preferred Program Code HD 8678C D Comments
273. he entry is saved in anticipation that a new frequency span is going to be entered The frequency span divided by the entered frequency step size must be less than 9999 If the span is not changed the step size will be adjusted to produce an integer number of steps between 1 and 9999 15 Theentered step size is larger than the currently defined frequency span The entry is saved in anticipation that the frequency span will be changed If the span is not changed the step size is set to equal to the span 1 step 3 149 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure Remote Procedure Stop Frequency Sweep The sweep stop frequency determines where the Signal Generator will end a sweep in each of the three sweep modes The sweep frequency limits are determined by setting either the start and stop frequency or the center frequency and frequency span Setting start and stop frequency will begin the sweep at the start frequency and end at the stop frequency Setting the center frequency and frequency span will start the sweep at one half the frequency span below the center frequency and end the sweep at one half the frequency span above the center frequency Setting the CW frequency when sweep is off will also reset the sweep center frequency to the same value Setting the center frequency or frequency span will automatically recalculate the appropriate sweep start and stop frequencies Resetting
274. he error code via front panel or HP IB before programming the Signal Generator with a new program string This will clear any previous messages that have not been read so the message indicated after sending the programming string will be the response to that programming string Program eas Enable Message output HP 86738C D Operation Detailed Operating Instructions Messages cont d Comments The Entry Error bit of the status byte is analogous to the MESSAGE key When the service request mask is used to generate an SRQ on an entry error the MESSAGE must be read via the front panel or HP IB before the SRQ is cleared Clearing the status byte will not clear SRQ until the message has been read Error Following are notes about certain error codes Messages 03 Invalid multiplier entry for system compatible instruments Error 03 is defined as BYPASS mode not functional below 2 GHz for non system compatible instru ments See paragraph 3 2 System Compatibility for more information 06 TheBYPASS modeand SYSTEM leveling cannot be selected for frequencies below 2 GHz This error is defined for system compatible instruments only See para graph 3 2 System Compatibility for more information 90 Auto Peak malfunction If error 90 occurs during pulse mode pulse performance may not be correct Clear the message and attempt an Auto Peak function If error 90 occurs again service is required Table 3 8 Error Messages 00
275. he extended status byte will be set BIT 8 This bit is always set to zero The status byte and the extended status byte can only be read using a controller All but _ one of the extended status bits can be read also on the front panel The POWER FAILURE ON bit can only be read using a controller The SELF TEST FAILED will be indicated by a message just after the instrument is turned on All of the other bits havea status annunciator that is turned on whenever the appropriate conditions exist A controller can be used to poll the Signal Generator while in remote mode to determine when a key is pressed or when the extended status byte changes This is useful in applications requiring retuning of test instruments under remote control while allowing an operator to manually tune the Signal Generator Serial Poll When a condition occurs that sets one of the bits of the status byte or the extended status byte the bit is set and remains set until it is cleared by the controller When the status byte is cleared all bits are first cleared and then updated to reflect the current status of the Signal Generator A serial poll is used to read the status byte without clearing any of the bits of the status byte To read the status byte the command SPOLL is used The status byteis then read into the controller The status byte is read as the sum of the weighted values of the bits See the status byte in the Comments section to determine bit weight value To cle
276. he frequency of the external oscillator to the desired modulation rate at an amplitude of 0 volts 3 Press the Signal Generator s AM meter mode key which is located near the front panel meter This will allow the amplitude of the external oscillator to be monitored as the desired AM depth 4 Adjust the external oscillator amplitude until the meter indicates the desired AM depth If the ALC UNLEVELED annunciator is lighted reduce the AM depth or the Signal Generator s output level until the annunciator extinguishes The AM range can be programmed to the 100 range 30 range or AM off using the program codes A3 A2 or Al respectively The actual AM depth is controlled by the amplitude of the external modulation source The meter mode can be set to AM with the program code T2 An overmodulation condition can be detected by the controller by checking the status byte The ALC UNLEVELED bit of the extended status byte is used to indicate AM overmodulation The AM range and the AM depth cannot be read by the controller The AM depth is determined by the amplitude setting of the external oscillator used to provide the mod ulating signal If the output impedance of the external oscillator is 600 ohms the AM depth can be determined by the controller by reading the external oscillator amplitude and multiplying by the programmed Signal Generator AM range To modulate the Signal Generator at 75 AM depth Local 1 Press the AM 100 key to
277. he means to control the output level of the system External mixers amplifiers and other equipment may be connected in the signal path with feedback from the last component in the signal path generating a system feedback voltage that is 0 volts at 0 dBm and has a sensitivity of 30 millivolts dB into a 50 ohm load The advantages of system leveling are automatic calibration to the Signal Generator s level meter temperature compensation built into the Signal Generator and the addi tion of a 20 dBm range to be used with external amplifiers When used with a 2 to 20 GHz amplifier the maximum leveled power of the Signal Generator can be as high as 23 dBm To set the Signal Generator for external system leveling 1 Connect the external equipment to the Signal Generator with the component generating the system feedback voltage at the end of the signal path 2 Press the Signal Generator s shift key and then press the SYSTEM key shifted DIODE key This sets the Signal Generator to system leveling mode which is indicated by the ALC INT key and the SYSTEM key being lighted 3 Reset the Signal Generator range to at least 10 dB above the range required for the desired RF output level The range may have to be adjusted to compensate for losses and gains in the RF signal path If the RF signal path will have a relatively high loss a higher Signal Generator range will be required 4 Connect the system feedback voltage to the external ALC inpu
278. he spectrum analyzer reference level 10 dB lower to bring the signal level near the reference graticule line 21 Read the difference between the new signal level and the center reference graticule line Calculate the actual power as follows NOTE The difference is positive if the signal is above the reference graticule negative if below Output level set in step 18 Difference measured in step 21 Actual level Record the actual level calculated in the following table The level reading should be within the limits specified 22 Repeat steps 19 through 21 with Signal Generator RANGE settings of 40 dB and 50 dB in step 19 Record the output level readings in the following table 23 Note the Signal Generator s signal level at 50 dBm on the spectrum analyzer display Remove the 20 dB attenuator set the spectrum analyzer s IF sensitivity 20 dB higher and reset the vertical sensitivity to the level noted before removing the 20 dB attenuator 24 Repeat steps 19 through 21 with Signal Generator RANGE settings of 60 dB through 90 dB Record the output level readings in the following table Results Actual 33 45 dBm ese 26 55 dBm 43 65 dBm a 36 35 dBm 53 85 dBm pS ee 46 15 dBm 64 05 dBm 55 95 dBm 74 25 dBm a 65 75 dBm 84 45 dBm n 75 55 dBm 95 65 dBm e 85 35 dBm 4 11 Performance Tests HP 8673C D ABBREVIATED PERFORMANCE TESTS PULSE MODULATION TEST Description
279. hed in to increase output power above 16 GHz HP 8673D only 22 0 GHz A high pass filter is switched in to reduce subharmonics HP 8673D only The following programs are written in BASIC for HP 9000 Series 200 or 300 controllers The following program is used to set the Signal Generator to the sweep start frequency specified by the variable called Expected The desired value must bein MHz and should be within the frequency range of the Signal Generator 10 SUB Sweep_start_set Err Expected Expected frequency in MHz 20 OUTPUT 719 USING 2A MG Read message from 8673 30 ENTER 719 USING 2A Message To clear any old messages 40 Frequency iINT Expected 1000 1000 Round off to nearest kHz 50 OUTPUT 719 USING 4A 5D DDD 2A CSFB Frequency MZ Update status 60 CALL Settled Wait for source to settle 70 OUTPUT 719 USING 2A MG i Check for message from 8673 80 ENTER 719 USING 2A Message 90 SELECT VAL Message 100 CASE 1 Frequency was out of range 110 Err 1 120 DISP WARNING Attempt to set sweep stop frequency out of range 130 CASE 10 140 Err 10 150 DISP WARNING Sweep start and stop frequency are equal 160 CASE 90 Auto Peak Error 170 Err 90 180 DISP WARNING Auto Peak error Service may be required 190 CASE ELSE 200 Err 0 Other errors not applicable 210 END SELECT 220 230 OUTPUT 719 USING 4A FBOA Requests current stop freq 240 ENTER
280. her than the Signal Generator setting in step 20 Set the local oscillator output power to 7 dBm Set the resolution bandwidth on the spectrum analyzer to 300 Hz or less Adjust the vertical sensitivity to place the peak of the 100 kHz IF signal on the center horizon tal graticule line This calibrates the center graticule line for an absolute reference power level of 20 dBm Set the RANGE of the Signal Generator 10 dB lower and adjust the VERNIER fora front panel meter reading of 0 dBm Set the spectrum analyzer reference level 10 dB lower to bring the signal level near the reference graticule line Read the difference between the new signal level and the center reference graticule line Calculate the actual power as follows NOTE The difference is positive if the signal is above the reference graticule negative if below Use the spectrum analyzer marker if available for best accuracy Output level set in step 27 T Difference measured in step 30 Actual level Record the actual level calculated in Table 4 3 The level reading should be within the limits specified Repeat steps 28 through 30 with Signal Generator settings of 40 dB and 50 dBin step 28 Record the output level readings in Table 4 3 Note the Signal Generator s signal level at 50 dBm on the spectrum analyzer display Remove the 20 dB attenuator set the spectrum analyzer s reference level 20 dB lower and reset the vertical sensitivity to the
281. hould be less than 25 4 71 Performance Tests HP 86738C D PERFORMANCE TESTS PULSE RISE FALL TIME AND OVERSHOOT TEST coni d Procedure cont d OUTPUT LEVEL FREQUENCY Overshoot MHz and Ringing 18 600 004 21 990 004 25 990 004 18 600 004 21 990 004 25 990 004 18 600 004 21 990 004 25 990 004 19 Tune the Signal Generator from 18 6 to 26 6 GHz at output levels of 10 dBm 0 dBm and 6 dBm Verify that rise and fall times are less than 40 ns and that overshoot and ringing are less than 20 Record the worst case results in the table below FREQUENCY QUTPUT LEVEL FALL Qvershoot MHz ns and Ringing 4 dBm 0 dBm 10 dBm 4 72 HP 8673C D Performance Tests PERFORMANCE TESTS 4 20 PULSE PEAK LEVEL ACCURACY TEST Specification Electrical Performance Characteristics Characteristics PULSE MODULATION Maximum Peak Power Same as in CW mode Peak Level Accuracy 1 5 dB 0 05 to lt 2 0 GHz 1 5 1 0 dB 2 0 to 26 0 GHz Description The output of the Signal Generator is switched between CW and pulse modulation mode using the CW level as a reference The difference in level between the two modes represents the peak level accuracy error Equipment Local Oscillator HP 8340A Pulse Generator HP 8013B Oscilloscope cece ees HP 1980B Pre Amp Power Amp HP 8447F MARGE saene lep cane E ise RHG DMS1 26 20 dB Attenuator HP 8493C Option
282. how the entered or adjusted number of steps on the left half of the display and the calculated sweep step size on the right half ofthe display The message key will lightif the number of steps are adjusted to indicate the change from the desired value Remote The programming string for setting the number of sweep steps is composed of a program code numeric data and the units terminator To program the number of steps to 350 steps the program string is SP35088 The program codes SS and SP can be used interchangeably in the above program string The alpha characters can be sent as upper or lower case or even mixed upper and lower case Description Number of Sweep Steps SS SP Preferred Program Code The Signal Generator digital sweep is composed of discrete frequencies that are produced sequentially The minimum step size is limited to the frequency resolution which is the minimum change in frequency that the Signal Generator can produce The number of steps is dependent on the frequency resolution and the sweep span The actual change in output frequency will not be uniform for some frequencies and may vary up to 2 kHz This is required to accommodate sweep step sizes that are not exact multiples of the frequency resolution The sweep steps averaged over several sweep points will be equal to the selected sweep step size An example of the averaging is defining a sweep step size of 10 kHz at a start frequency of 15 GHz
283. how the entered frequency until the units key is released The frequency display should now be right justified The frequency could also have been entered as 16 232334 GHz or 162382334 kHz The only difference is the placement of the decimal point and the units key pressed after the frequency has been entered using the numeric keypad Remote The programming string for setting the sweep center frequency is composed of a program code numeric data and the units terminator The frequency may be programmed in units of GHz MHz kHz or Hz To program the Signal Generator to 16232 334 MHz the possible program strings are CF16 232334GZ or CF16232 334MZ or CF16232334KZ or CF16232334000HZ The alpha characters can be sent as upper or lower case or even mixed upper and lower case Program Applicable Code gwink Units CF Center Frequency FR Preferred Program Code 3 57 Operation HP 8678C D Detailed Operating Instructions Comments Programming Example 3 58 Center Frequency Sweep conra Due to the use of frequency multiplication to generate frequencies above 6 6 GHz the frequency sometimes cannot be set precisely to a desired value Frequencies below 6 6 GHz can be set to the nearest 1 kHz All frequencies between 6 6 and 12 3 GHz can be set within 2 kHz of the desired value Frequencies between 12 8 and 18 6 GHz can be set within 3 kHz of the desired value and frequencies between 18 6 a
284. ht hand side of the channel If you see the word METRIC the metric screws are required 2 5 Power Requirements The Signal Generator requires a power source of 100 120 220 or 240 Vac 5 to 10 48 to 66 Hz single phase for Option 003 instruments 400 Hz single phase and 120 Vac 5 10 only Power consumption is 500 VA maximum WARNINGS This is a Safety Class I product that is pro vided with a protective earth terminal An uninterruptible safety earth ground must be provided from the main power source to the product input wiring terminals power cables or supplied power cable sets Whenever it is likely that the protection has been impaired the product must be made inoperative and be secured against any unintended operation If this instrument ts to be energized via an external autotransformer make sure the auto transformer s common terminal ts connected to the neutral that is the grounded side of the mains supply 2 6 Line Voltage and Fuse Selection BEFORE PLUGGING THIS INSTRUMENT into the mains line voltage be sure the cor rect voltage and fuses have been selected Verify that the line voltage selection cards and the fuses are matched to the power source Refer to Figure 2 1 Line Voltage and Fuse Selection Fuses may be ordered under HP part numbers listed in the following table 2 1 Installation Line Voltage and Fuse Selection cont d 220 240V 2110 0055 2110 0
285. icator is on or flashing the instrument self diagnostics detected a malfunction during turn on Press and hold the MESSAGE key to display the message code in the FREQUENCY MHz display Any code other than 00 represents an error Refer to Table 3 8 or the operating information pull out card for a complete listing of message codes and the malfunctions they represent Occasionally due to line transients or other external conditions the instrument self diagnostics may indicate a false error Pressing the MESSAGE key and repeating the turn on procedure will usually differentiate between real and false errors Errors that repeat are real 7 Setthe FREQ STANDARD INT EXT switch to EXT Verify that the EXT REF and UNLOCKED status annunciators turn on Set the switch back to INT The status annunciators should then turn off 8 Press RCLO Verify that the instrument is now preset to the following conditions RF OUTPUT to ON ALC mode to INTERNAL OUTPUT LEVEL RANGE to 70 dBm 0 dB for Option 004 and 005 AUTO PEAK to ON Meter scale to LVL AM FM and Pulse Modulation to OFF FREQUENCY to 3000 000 MHz FREQ INCR to 1 000 MHz START to 2000 000 MHz STOP to 4000 000 MHz AF to 2000 000 MHz SWEEP to OFF STEP to 100 Steps 20 000 MHz DWELL to 20 ms TUNE Knob to ON All Status Annunciators off MESSAGE key light off BYPASS NORMAL to NORMAL Frequency Check The FREQUENCY MHz display and UNLOCKED status annunciator are used to check
286. ignal Generator to a known state cont d 33 Set the test oscillator to 10 kHz ata minimum output level or 0V Then connect the test oscillator and oscilloscope to the Signal Generator as shown in Figure 3 8 34 Set the Signal Generator to each setting shown in the table below For each setting slowly increase the test oscillator s output level starting from 0V while observing the Signal Generator s meter in AM mode The meter should indicate a smooth and continuous increase in AM depth When the meter displays the AM indicated in the table verify that the oscilloscope shows the corresponding voltage The UNLEVELED status annunciator should remain off at all times Signal Generator Oscilloscope FREQUENCY RANGE VERNIER AM Key Display 1 GHz Ode Odin 0 75V peak 18 GHz 0dB 0 dBm 0 75V peak HP 8673D only 24 GHz 0 dB 3 dBm 0 75V peak 26 GHz 0dB 5 dBm 0 5V peak 26 GHz 0dB 5 dBm 1 0V peak 35 Press AM OFF Disconnect the test oscillator and oscilloscope from the Signal Generator FM Check The front panel meter is used to monitor input signal level which is proportional to FM deviation A spectrum analyzer can be used to monitor the signal at the RF OUTPUT connector for greater assurance of FM performance The FM OVERMOD status annunciator detects a FM overmodulation condition 36 Press RCL 0 to preset the Signal Generator to a known state Set Output Level RANGE to 0 dB Output Level VERNIER to 0 dB
287. into a baseband check 2 0 to 6 6 GHz and a check for bands 2 3 and 4 6 6 to 12 3 GHz 12 3 to 18 6 GHz and 18 6 to 26 0 GHz respectively Frequency Counter HP 5343A HP 8673C D SYNTHESIZED FREQUENCY SIGNAL GENERATOR COUNTER FREQUENCY FREQUENCY STANDARD IN STANDARD QUT RF OUTPUT Figure 4 10 Frequency Range and Resolution Test Setup Baseband Test 1 Connect the equipment as shown in Figure 4 10 Set the Signal Generator rear panel FREQ STANDARD INT EXT switch to EXT Remove the FREQ STANDARD jumper and connect A3J10 to the 10 MHz frequency standard output of the frequency counter With the Signal Generator and the frequency counter sharing a common timebase the frequency counter should agree with the Signal Generator FREQUENCY MHz display 1 count with any selected frequency counter resolution 2 Select 1 kHz display resolution on the frequency counter 3 Press RCL 0 on the Signal Generator Set the Signal Generator to 50 MHz at an output level of 0 dBm 4 23 Performance Tests HP 8673C D PERFORMANCE TESTS FREQUENCY RANGE AND RESOLUTION TEST contra Procedure cont d 4 24 4 Verify that the frequency counter reads 50 000 MHz 1 count due to the accuracy Q 6 of the frequency counter 49 999 MHz 50 001 MHz Set the Signal Generator frequency increment to 1 kHz Using the TUNE knob tune the Signal Generator to each of the frequencies listed below Verify that the NO
288. ion should be performed during measurements that have large frequency changes and extremely long measurement cycles To ensure that pulse performance is optimized before making a measurement execute an Auto Peak operation before each measurement The status byte may be monitored to determine when the Auto Peak operation is complete The SOURCE SETTLED bit is set when the Auto Peak operation is finished The Signal Generator uses frequency multiplication to generate frequencies above 6 6 GHz To produce fast rise times when the frequency is multiplied a pulse injection circuit is used to pre bias the multiplication circuits The pulse injection circuit is critical for fastest rise times and minimum overshoot The Auto Peak operation measures critical parameters for the pulse injection circuit when pulse mode is enabled With pulse mode enabled a frequency change of 20 MHz ora VERNIER change 0 4dB or more will trigger an Auto Peak operation During the Auto Peak the Signal Generator will switch to CW mode for approximately 200 microseconds while the Auto Peak operation is performed Pulse mode is then re enabled and the pulse injection circuitry uses the measured parameters to optimize the pulse risetime The bursts of CW power due to changes in the VERNIER setting can be eliminated by using an internal scratch pad memory When an Auto Peak is performed the para meters required for the pulse injection circuitry are stored in the scratch pad
289. ion up to 90 depth at rates as high as 100 kHz is typically available using external diode leveling mode Description The response time for a level change using diode leveling mode will typically be about 1 millisecond in CW mode and about 0 1 millisecond in AM mode The square law region for a point contact diode is typically 45 to 20 dBm The square law region for a Schottky hot carrier diode is 50 to 20 dBm External diode leveling is not temperature compensated Power drift over temperature is dependent on the detector used Frequency recalibration may be required in environments that are not temperature stabilized The Signal Generator range selected will have a direct affect on ALC The range selected depends primarily on the losses and gains in the RF signal path In most applications the ALC dynamic range is limited by the maximum RF power available at a given frequency For example with 15 dB of loss in the signal path the Signal Generator must compensate with atleast 15 dB of additional RF output power With no internal attenuation 0 or 10 dB ranges the Signal Generator would have to supply 15 dBm for a leveled signal at 0 dBm Since the maximum RF output power is specified at less than 13 dBm the Signal Generator may not be able to supply the required power Output level ranges of 10 to 90 dB add attenuation to the RF signal path These ranges are useful mainly when attempting to level low amplitude sign
290. ions H SWITCHING TIME Frequency to be within CW and AM only the specified resolution AUTO PEAK disabled and amplitude to be NORMAL mode within 3 dB of final level This test measures the frequency switching speed of the Signal Generator The Signal Generator output is mixed with a local oscillator whose output frequency is set to the frequency resolution specification above or below the destination frequency The difference frequency IF is displayed on the oscilloscope Frequency switching speed is measured using a digitizing oscilloscope The oscilloscope is set to trigger the digitizing process at the beginning of the frequency change Delayed sweep is used to improve the measurement resolution As the unit under testis switched from the starting frequency to the destination frequency the IF signal will pass through zero when the unit under test frequency is equal to the local oscillator frequency This will generate a phase reversal The last phase reversal of the IF frequency is the time that the unit under test is within the specified frequency resolution The amplitude recovery time is tested using the same measurement setup The 3 dB amplitude points of the IF signal are calibrated on the oscilloscope display and the amplitude recovery time is tested to ensure that the IF levelis within 3 dB of the final level NOTE Due to the mechanical relays that are switched during certain frequency changes a digitizing o
291. isappears Continue entering the correct digits until the dwell time in the FREQUENCY MHz display is correct 3 Press the ms key to finish the sweep dwell time entry The dwell time will be displayed until the ms key is released The Signal Generator accepts any dwell setting between 1 and 255 milliseconds The format of the remote programming follows the front panel key sequence The program code DW is sent followed by the desired dwell time and the units MS The dwell times can be read by the controller using the output active program code suffix To read the current dwell time the program string DWOA is sent and then the dwell time is read Ifread as a string the format is the program code DW followed by the dwell time in milliseconds and the units terminator MS To set the sweep dwell time to 20 milliseconds Locai 1 Press the DWELL key 2 Key in 20 using the numeric keypad The FREQUENCY MHz display should show 20 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the ms units key to finish the sequence The FREQUENCY MHz display should show the entered dwell time until the ms key is released Remote The programming string for setting the dwell time is composed of a program code numeric data and the units terminator To program the dwell time to 20 milliseconds the program string is DW20MS The alpha characters can be sent as upper or lower case or even mixe
292. it byte repre senting one or more data lines see table below and 3 38 when addressed to talk the Signal Generator sends the binary byte that it just received Refer to Section VIII Service for additional information HP IB Data Line DIO8 DIO7 DIOS DIOS DIO4 DIOS DIO2 DIO1 vn ela lele e ele Output Status After receiving the program code OS Output Status and when addressed to talk the Signal Generator sends two binary bytes each 8 bits wide The first byte is identical to the Status Byte of the Serial Poll The second byte is the Extended Status Byte which provides additional information See Figure 3 11 for a description of each Status Byte Bits in the maim Status Byte are cleared upon execution of the Output Status func tion or the Clear Status CS program code Bits on the Extended Status Byte are cleared by removing the causing condition and performing the Output Status function HP 86738C D 3 34 Receiving the Clear Message The Signal Generator responds to the Clear mes sage by assuming the settings detailed in Table 3 5 The Signal Generator responds equally to the Selected Device Clear SDC bus command when addressed to listen and the Device Clear DCL bus command whether addressed or not The Clear message clears any pending Require Service message Table 3 5 Response to a Clear Message Parameter Condition Immediate Cleared Cleared Execution Mode Request Mask
293. it using the freq increment control Swept signals from the instruments will be offset by the FREQ INCREMENT value In each sweep mode of operation the designated Slave Unit will have the MANUAL and SINGLE pushbutton lamps lit The designated Master Unit will have only the selected mode pushbutton lamp lit A step by step example follows a Interconnect two instruments for HP IB Designate one instrument as the Master Unit and set its HP IB Address to 50 Designate the other instrument as the Slave Unit and set its HP IB Address to 40 b On both units set SWEEP START to 2000 MHz and SWEEP STOP to 12000 MHz On both units set either the number of steps or step size to the desired value As one example set both master and slave units for 500 steps c On the Slave Unit select a 50 MHz offset using the FREQ INCR and the FREQ INCRE MENT or L to increase the Slave Unit frequency by 50 MHz HP 8673C D SWEEP Mode in MASTER SLAVE Configuration cont d d Press and hold SWEEP START on the Slave Unit and check for a 50 MHz offset Display should read 12050 MHz e For AUTO Mode Press AUTO on Master Unit Slave Unit will have MANUALand SINGLE key indicators lit f For MANUAL Mode Press MANUAL on Master Unit Slave Unit will have MANUAL and SINGLE key indicators lit On Master Unit enable TUNE ON OFF Use the TUNE Knob of the Operation Master Unit to tune both Master and Slave Units according to STEP SIZE set on
294. itch to STBY then to ON Place the Signal Generator in serial SPOLL 719 SPOLL 719 poll mode causing it to send the Status Byte message 3 27 Operation _ HP 8678C D OPERATOR S CHECKS HP 18 Functional Checks cont d Status Byte Message contd Operator s The controller s display should read 12 Response Require Service Message Note This check determines if the Signal Generator can issue the Require Service message set the SR bus control line true This check can be performed in either local or remote mode Hescription Series 200 300 HP 85B BASIC Send a Data message to set the OUTPUT 719 USING OUTPUT 719 USING RQS Mask to 32 2A B 1 32 2A B 1 32 Send a Data message containing OUTPUT 719 FR35GZ OUTPUT 719 FR35GZ an invalid frequency This causes a Require Service message to be sent Operator s Check that the SRQ annunciator is on Response Note In the next step a short program is required if series 200 300 is the controller Read the binary status of the con 10 V 0 STATUS 7 2 V troller s HP IB interface and store 20 STATUS 7 7 V the data in variable V in this step 7 is the interface s select code Display the value of the SRQ bit in 30 DISP SRQ DISP SRQ BIT V 6 this step 10 is the SRQ bit for the BIT V 10 series 200 300 and 5 is the SRQ bit for the HP 85B numbered from 0 40 END Operators Ch
295. its terminator SS To set the sweep step size to 455 kHz Local 1 Press the STEP key 2 Key in 455 using the numeric keypad The FREQUENCY MHz display should show 455 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the kHz units key to finish the sequence The FREQUENCY MHz display should show the calculated number of steps on the left half of the display and the entered or adjusted sweep step size on the right half of the display The message key will light if the sweep step size is adjusted to indicate the change from the desired value The sweep step size could also have been entered as 455 MHz or 000455 GHz The only difference is the placement of the decimal point and the units key pressed after the sweep step size has been entered using the numeric keypad Remote The programming string for setting the sweep start frequency is composed of a program code numeric data and the units terminator The frequency may be pro grammed in units of GHz MHz kHz or Hz To program the sweep step size to 455 kHz the possible program strings are SP 000455GZ or SP 455MZ or SP455KZ or SP455000HZ In addition the program code SS can be used in place of SP in the above program strings The alpha characters can be sent as upper or lower case or even mixed upper and lower case Preferred Program Code The Signal Generator digital sweep is composed of discr
296. l NOTE Do not touch the oscilloscope s vertical position controls after the reference pulse base line has been set Switch the Signal Generator to PULSE NORM Without adjusting the oscillo scope s vertical sensitivity controls measure the difference between the CW peak reference level and the average peak pulse level excluding any overshoot See Figure 4 31 CW PEAK REF r LEVEL PULSE BASE LINE Figure 4 31 Pulse Peak Level Accuracy Measurement Measure the peak level difference in percent Using a 5 division peak reference each division represents a 20 difference Measured difference must be within the limits of 10 8 to 18 8 10 8 corresponds to 0 5 divisions on the oscillo scope 18 8 corresponds to 0 9 divisions This is equal to 1 5 dB 1 dB Record the measurement in the following table 11 Repeat steps 1 through 10 for the frequencies and levels listed in the following table Record the results 4 74 HP 8673C D Performance Tests PERFORMANCE TESTS PULSE PEAK LEVEL ACCURACY TEST contd cont d Difference FREQ LEVEL FREQ LEVEL 1 938 GHz 10 dBm 2 0 GHz 8 dBm 6 61 GHz 4 dBm 6 68 GHz 8 dBm 0 dBm 10 dBm 12 3 GHz 4 dBm 0 dBm 10 dBm 12 37 GHz 6 6 GHz 4 dBm 6 67 GHz 8 dBm HP 8673D only 18 61 GHz 4 dBm 18 68 GHz 0 dBm 10 dBm 22 1 GHz 4 dBm 22 17 GHz 0 dBm 10 dBm Performance Tests HP 8673C D PERFOR
297. l message is the means by which the controller sets the Remote Enable REN bus control line false The Signal Generator returns to local mode full front panel control when it receives the Clear Lockout Set Local mes sage When the Signal Generator goes to local mode the front panel RMT annunciator turns off 3 39 Operation 3 40 Receiving the Pass Control Message The Signal Generator does not respond to the Pass Control message because it does not have this con troller capability 3 41 Sending the Require Service Message The Signal Generator sends a Require Service message if one or more of the following conditions exist and if it has been pre programmed to send the message by the Request Mask e Front Panel Key Pressed when the Signal Generator is in local mode and one of the front panel keys is pressed Front Panel Entry Complete when the Sig nal Generator is in local mode and is finished processing a front panel entry Change in Extended Status when one of the bits on the Extended Status Byte changes e Source Settled when the Signal Generator is settled Switching transients occur when RF and AUTO PEAK are turned on and when FM ranges and frequency are changed If the controller responds to the Signal Generator as soon as the source is settled instead of waiting a specified time program speed is increased e Entry Error When an invalid keystroke or program command occurs e New Sweep Paramet
298. lative to External AM input 7 Set the audio source frequency to 10 kHz with an output amplitude of 0 636 Vrms as read on the digital voltmeter This corresponds to 90 AM depth 8 Read the actual AM depth on the measuring receiver The reading should be within 10 1 of 90 AM Record the reading in the table below 9 Repeat steps 7 and 8 with the frequencies and modulation rates listed in the table below Signal Local Generator Oscillator Modulation Rate Frequency Frequency 6 6 GHz 6 5 GHz 100 1 6 6 GHz 6 5 GHz a 100 1 6 6 GHz 6 5 GHz 100 1 10 GHz 9 9 GHz I 100 1 14 GHz 13 9 GHz f a 100 1 HD 8673D only 18 6 GHz 18 5 GHz L OOS 22 GHz 21 9 GHz EA HE TOO HP 8673C only 10 Set the HP 8673C as follows FREQUENCY eee 18 6 GHz OUTPUT LEVEL RANGE 0dB OUTPUT LEVEL VERNIER 3 dBm 4 79 Performance Tests HP 8673C D PERFORMANCE TESTS AM ACCURACY TESTS contd Procedure 11 Tune the local oscillator to 18 5 GHz with an output amplitude of 8 dBm cont d 12 Set the modulation source frequency to 10 kHz Adjust the output level for 0 636 Vrms as read on the digital voltmeter 13 Read the AM depth on the measuring receiver The reading should be within 10 1 of 90 AM depth Record the reading AM depth 79 9 100 1 4 80 HP 86738C D Performance Tests PERFORMANCE TESTS 4 23 INCIDENTAL FM Specification Description Equipment Pr
299. lay for frequency changes of more than 1 GHz or band crossings This delay is required to eliminate the effects of filter drift after a large frequency change The filter is immediately tuned to the correct frequency when the frequency change occurs and then the algorithm waits for the filter to settle In applications that require a very fast measurement cycle the Auto Peak may be performed immediately after the frequency change by sending the program code K2 after the frequency change This will immediately perform an Aute Peak operation but will not correct for the filter drift as the filter settles Some experimentation may be required to determine whether a measurement system can benefit from the faster Auto Peak operation 3 49 Operation HP 86738C D Detailed Operating Instructions Remote Procedure cont d Program Codes Comments Programming Example 3 50 Auto Peak conra The Signal Generator has an additional tracking filter in NORMAL mode that is used between 6 and 22 GHz The physical location of the additional filter requires a long settling time during the Auto Peak operation The K2 program code will not speed up the peaking of the second filter Therefore to maximize the speed of the K2 program code the Signal Generator should be in the BYPASS mode The SOURCE SETTLED bit of the extended status byte will be set to indicate that the Auto Peak operation has been completed Since the settling times of other ope
300. lay multiplier Remote The programming string for setting the display multiplier to 2is MY2X F The alpha non numeric characters can be sent as upper case or lower case or even upper and lower case Once a display multiplier is entered all frequencies except offset will be multiplied by the entered multiplier This allows the controller to read the system frequency over the bus and also the multiplier in case the Signal Generator s actual RF output frequency is to be determined Program Code Description Frequency multiplication reduces the frequency resolution of the multiplied frequency For example an RF output frequency of 16 GHz corresponds to a frequency resolution of3 kHz If an external frequency doubler multiplier 2 is used the 32 GHz multiplied frequency would have a frequency resolution of 6 kHz When a frequency offset and a display multiplier are entered the displayed frequency is multiplied before being offset For an application such as a harmonic mixer the desired harmonic can be entered as the multiplier and the desired IF frequency as an offset Once these two values are entered the frequency thatis to be downconverted can be entered directly on the Signal Generator The actual Signal Generator frequency will be the entered frequency offset by the IF frequency and then divided by the harmonic multiplier The calculations are internal to the Signal Generator and frees the user from the tedious ca
301. lculations required to set the actual frequency present at the local oscillator port of the harmonic mixer 3 103 Operation HP 8673C D Detailed Operating Instructions Comments Contd Programming Exampie Error Messages 3 104 Multiplier Mode conra The system output frequency must be linearly related to the actual output of the Signal Generator An example of a linear relationship is that the ratio of the system output frequency to the Signal Generator output frequency is a constant Care must be taken with a complicated system to maintain a linear relationship to preserve display accuracy The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program is used to set a frequency display multiplier Entering a 1 will disable frequency display multiplier mode 10 SUB Display_mult Err Multiplier 20 IF Multiplier gt 99 OR Multiplier lt 1 THEN 30 DISP WARNING Display multiplier is out of range 40 Err 1 50 SUBEXIT 60 END IF 70 Mult iNT Multiplier Make sure it is an integer 80 90 OUTPUT 779 USING 2A DD 2A MY Mult XF 100 110 SUBEND 01 Entered frequency is not within the range of the Signal Generator 03 Invalid multiplier entry fro system compatible instruments Error 03 is defined as BYPASS mode not functional below 2 GHz for non system compatible instru ments See paragraph 3 2 System Compatibility for more information HP 8673C D D
302. less than 1 For pulse modula tion the source should have TTL output levels gt 2 4V for a TTL high state and lt 0 4V for a TTL low state and 50 ohms nominal impedance Pulse General Information repetition frequency rates should be 50 Hz to 1 MHz with transition times lt 10 ns 1 11 ELECTRICAL EQUIPMENT AVAILABLE The Signal Generator has an HP IB interface and can be used with any HP IB compatible comput ing controller or computer for automatic systems applications The HP 8116A Pulse Function Generator is ade quate for modulating the Signal Generator and meeting stated standards This remotely program mable signal source is convenient for full remote control of modulation levels and rates The Synthesizer Interface Cable part number 5061 5391 provides an interface to the HP 8349B Microwave Amplifier This provides calibrated output level under control of the system compat ible Signal Generator This cable as well as the HP 8349B Microwave Amplifier is required for use with the HP 83550 family of frequency multi pliers For more information see paragraph 3 2 System Compatibility 1 12 RECOMMENDED TEST EQUIPMENT Table 1 3 lists the test equipment recommended for testing adjusting and servicing the Signal Genera tor Table 1 4 lists the test equipment recommended for Abbreviated Performance Tests Essential requirements for each piece of test equipment are described in the Critical Specifications column O
303. level noted before removing the 20 dB attenuator 4 56 HP 8673C D rivance Tests PERFORMANCE TESTS ABSOLUTE LEVEL ACCURACY TESTS cont d Procedure 33 Repeat steps 28 through 30 with Signal Generator RANGE settings of 60 dBm Contd through 90 dBm Record the output level readings in Table 4 2 34 Repeat steps 20 through 34 with Signal Generator frequencies of 4 GHz 10 GHz 14 GHz and HP 8673D only 20 GHz 4 57 Performance Tests ABSOLUTE LEVEL ACCURACY TESTS cont d Procedure cont d 4 58 Table 4 3 Low Level Accuracy Test Record 50 MHz 30 dBm 40 dBm 50 dBm 60 dBm 70 dBm 80 dBm 90 dBm 4 0 GHz 30 dBm 40 dBm 50 dBm 60 dBm 70 dBm 80 dBm 90 dBm 10 GHz 30 dBm 40 dBm 50 dBm 60 dBm 70 dBm 80 dBm 90 dBm 14 GHz 30 dBm 40 dBm 50 dBm 60 dBm 70 dBm 80 dBm 90 dBm HP 8673D only 20 GHz 30 dBm 40 dBm 50 dBm 60 dBm 70 dBm 80 dBm 90 dBm br Min 32 75 dBm 42 85 dBm 52 95 dBm 3 05 dBm 73 15 dBm 83 25 dBm 93 85 dBm 32 75 dBm 42 85 dBm 52 95 dBm 63 05 dBm 73 15 dBm 83 25 dBm 93 35 dBm 33 00 dBm 43 10 dBm 53 20 dBm 63 30 dBm 73 40 dBm 83 50 dBm 93 60 dBm 34 45 dBm 43 65 dBm 53 85 dBm 64 05 dBm 74 25 dBm 84 45 dBm 95 65 dBm 34 05 dBm 44 25 dBm 54 45 dBm 64 65 dBm 74 85 dBm 85
304. level that is beyond its capability Calibrated output level is only guaranteed with the ALC UNLEVELED annunciator extinguished When the ALC UNLEVELED annunciator is lighted the Signal Generator s LVL meter will indicate approximate available power For example if the Signal Generator is capable of 9 dBm leveled power at a given frequency and the RF output level is set for 13 dBm the level meter will give an indication of 1 dBm to indicate that the maximum available power is 9 dBm The choice of RANGE and VERNIER settings can have a significant effect on some applications If a continuous 13 dB range about a specific output level is required the VERNIER alone can be used If 10 dB steps are required the RANGE up and down keys may be used to step the RF output level in 10 dB steps High VERNIER settings give the worst case performance for harmonics while the low VERNIER settings give the worst case performance for subharmonics For applications requiring lowest harmonics use a higher range setting to allow setting the VERNIER at a lower setting For example if an output level of 10 dBm is required with a mini mum harmonic use the 0 dB range and the 10 dBm setting of the VERNIER Subharmonics are due to the frequency multiplication process within the Signal Generator Frequencies above 6 6 GHz are generated by multiplying the fundamental 2to 6 6 GHz microwave signal by two three or four to provide output frequencies up to 2
305. llator to 7000 020 MHz Set the spectrum analyzer frequency span per division to 500 Hz Adjust the spec trum analyzer controls to place the peak of the 20 kHz IF signal on the top graticule line Verify that the line related harmonics of the Signal Generator do not exceed the values shown below Record the highest spurious signal level in each offset band 6 6 12 3 GHz lt 300 Hz offset _ lt 44 dBe Set the spectrum analyzer frequency span to 1 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level 300 Hz 1 kHz offset Bd dBc Set the spectrum analyzer frequency span to 5 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level gt 1 kHz offset SEE lt 9 dBe Tune the Signal Generator to 16 000 000 MHz Tune the local oscillator to 16 000 020 MHz Set the spectrum analyzer frequency span to 500 Hz Adjust the spectrum analyzer controls to place the peak of the 20 kHz IF signal on the top graticule line Verify that the line related harmonics of the Signal Generator do not exceed the values shown below Record the highest spurious signal level in each offset band 12 3 18 6 GHz lt 300 Hz offset ___mm m lt 40 dBe Set the spectrum analyzer frequency span to 1 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level 300 Hz 1 kHz offset Ws lt 50 dBe 4 46 HD 86738C D Perform
306. m and FM DEVIATION range to 0 03 MHz Then set the meter scale to FM HP 8673C D SYNTHESIZED SIGNAL GENERATOR caf JE E ae OSCILLOSCOPE 8680 G TEST OSCILLATOR OUTPUT ENPUT BNC TEE Figure 3 9 FM Functional Check Setup 3 21 Operation HP 86738C D OPERATOR S CHECKS Basic Functional Checks cont d Procedure 37 Set the test oscillator to 3 MHz at minimum output level of OV Then connect test contd oscillator and oscilloscope to the Signal Generator as shown in Figure 3 9 38 Slowly increase the output level of the test oscillator starting from OV until the Signal Generator s meter reads full scale Verify that the meter increases slowly and continuously and that the FM OVERMOD status annunciator remains off The oscilloscope display should be approximately 1V peak 39 Repeat step 38 for each of the following FM deviation ranges 0 1 0 3 1 3 and 10 MHz 40 Set the Signal Generator s FM DEVIATION range to 10 MHz Increase the test oscillator output level until a full scale reading is obtained Decrease the test oscillator frequency slowly until the Signal Generator s FM OVERMOD status annunciator turns on This should occur at a modulation frequency of 1 to 2 MHz modulation index approximately 6 5 41 Press FM DEVIATION MHz OFF and disconnect the test oscillator and oscillo scope from the Signal Generator Puise Modulation Check Pulse modulation is checked using various front pan
307. med to any of the six ranges or off The actual FM peak deviation is controlled by the external oscillator and is not directly programmable via the Signal Generator The meter mode can be set to FM mode with the program code T3 An overmodulation condition can be detected by the controller by checking the status byte The FM Overmodulated bit of the extended status byte is used to indicate FM over modulation in remote mode The FM range and the FM peak deviation cannot be read by the controller The FM peak deviation is determined by the amplitude setting of the external oscillator used to provide the modulating signal and the selected FM deviation range If the output impedance of the external oscillator is 50 ohms the FM peak deviation can be deter mined by the controller by reading the external oscillator amplitude and multiplying by the programmed Signal Generator FM range To FM modulate the Signal Generator at 100 kHz peak deviation at a rate of 10 kHz Local 1 Press the FM 0 1 key to set the Signal Generator for 100 kHz maximum deviation Press the FM key near the Signal Generator s front panel meter to set the meter to FM mode 3 83 Operation HP 8673C D Detailed Operating Instructions Example contd Program Codes gt Comments Programming Example 3 84 Frequency Modulation contrat 2 Set the external oscillator to 10 kHz and adjust the amplitude to zero volts 3 Connect the external oscill
308. mments The format of the remote programming follows the front panel key sequence To program the CW frequency the program code FR or CW is sent followed by the desired frequency and the units GZ MZ KZ or HZ The CW programming code also turns off sweep if any sweep mode is active when the program code is received by the Signal Generator Once a frequency is programmed the SOURCE SETTLED bit of the status byte can be monitored to determine when the frequency has settled Once this bit is set the NOT PHASE LOCKED bit in the extended status byte may be checked to ensure that the instrument is working correctly The NOT PHASE LOCKED bit is not valid until after the SOURCE SETTLED bit has been set Both the set CW frequency and the current RF output frequency can be read by the controller using the output active program code suffix or a special program code To read the CW frequency not the output frequency if the frequency was rounded send the program codes FROA and then read the frequency The Signal Generator will send the CW frequency in fundamental Hz units If the CW frequency is read as a string the format will be the program code CF followed by the CW frequency in Hz and then the units terminator Hz To read the current output frequency the program code OK is sent and then the current RF output frequency can be read The format is the same as the FROA method described above This method should not be used while sweeping as th
309. mode the local RF level setting is preserved This feature also allows the controller to read the local VERNIER setting by briefly switching to remote to read the VERNIER setting and then returning the Signal Generator to local mode The VERNIER setting is read by sending the program codes VEOA and then reading the setting The Signal Generator will send the VERNIER setting in fundamental dBm units Ifthe VERNIER setting is read as a string the format will be the program code VE followed by the VERNIER setting in dBm and then the units terminator DM dBm The RF output level is read directly by sending the program codes LEOA and then reading the RF output level The Signal Generator will send the RF output level in fundamental dBm units Ifthe RF output level is read as a string the format will be the program code LE followed by the RF output level in dBm and then the units terminator DM dBm The program codes AP or PL can also be used in place of LE but the Signal Generator will always send the program code LE when the RF output levelis read as a string To set the RF output level to 56 dBm Local 1 Pressthe ALC INT key to place the Signal Generator into internal ALC mode The process for setting the RF output level for external ALC modes is covered under the appropriate section of the Detailed Operating Instructions 2 Set the RANGE to the lowest range that is less than 10 dB above the power or 50 dBm in this case 3
310. more than doubled by activating any sweep mode Pulse modulation uses a sample and hold system to maintain pulse level accuracy A capacitor is used to hold the automatic level control ALC circuit setting between pulses When pulse and amplitude modulation are used together the sampling capacitor has the effect of reducing the effective AM bandwidth The effective AM bandwidth when pulse mode and AM are enabled and sweep is disabled is calculated as follows Bandwidth 4 kHz P PRF Where Pw is the pulse width in seconds PREF is the pulse repetition frequency in Hz For example a pulse width of 10 microseconds at a pulse repetition rate of 10 kHz will yield an effective AM bandwidth of 400 Hz The effective AM bandwidth is directly proportional to the duty cycle Pw PRF The following program is written in BASIC for HP 9000 Series 200 er 300 controllers The program will set the AM range to an appropriate setting and return the peak voltage required into 600 ohms for the AM depth specified by Depth 3 47 Operation HP 8678C D Detailed Operating Instruction Amplitude Modulation conta Programming 10 SUB Am_depth Err Depth V_required Depth is in Example 20 cont d 30 SELECT Depth 40 CASE lt 30 50 Depth A2 Code for 30 depth 60 V_required Depth 30 l In peak volts into 600 ohms 70 CASE lt 100 80 Depth A3 Code for 100 depth 90 V_required Depth 100 in peak volts into 600 ohms 100 CASE ELSE
311. mote message The Signal Generator can send a Require Service mes sage a Status Byte message and a Status Bit message Remote to Local Mode Changes The Signal Gen erator switches to local from remote whenever it receives the Local message GTL when addressed to listen or the Clear Lockout Set Local message The Clear Lockout Set Local message sets the Remote Enable control line REN false The Sig nal Generator can also be switched to local by pressing the front panel LOCAL key assuming Local Lockout is not in effect With the excep tion of VERNIER which returns to the front panel setting the Signal Generator s control settings remain unchanged with the Remote to Local transition Local Lockout When a data transmission is inter rupted which can happen by pressing the LOCAL key to return the Signal Generator to local mode the data could be lost This would leave the Signal Generator in an unknown state To prevent this a local lockout is recommended for purely automatic HP 8678C D Operation Table 3 3 Message Reference Table 1 of 2 Related Med ea KA Controls All front panel functions except the LINE switches and the Backspace key and remote only functions are bus programmable Yes If in remote and addressed to listen the Signal Generator executes a pre viously selected program code It responds equally to the Group Execute l Trigger GET bus command and program code
312. mote mode a Digital to Analog Converter DAC is substituted for the front panel VERNIER control The resolution of the front panel VERNIER is as fine as can be measured while the resolution of the remote mode DAC is 0 1 dB Optimum AM performance is achieved for VERNIER settings of 0 dBm and below Highest harmonic levels occur at high VERNIER settings while subharmonics and spurious signals are highest at low VERNIER settings Changing ranges below 0dB will result in approximately the same performance as the 0 dB range at the lower RF output level The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program will set the output level between 100 and 13 dBm Ifalevel above0dBm is set and the Signal Generator is not leveled an error will be reported 10 SUB Rt_level Err Expected Expected is in dBm 20 30 If Expected lt 100 OR Expected gt 13 THEN 40 Err 1 50 DISP ERROR Requested output level is out of range 60 SUBEXIT 70 END IF 80 90 OUTPUT 719 USING 2A MG Clear old messages 100 ENTER 719 USING 2A Message 110 120 OUTPUT 719 USING 4A 4D D 2A CSLE Expected DM Set the level 130 140 OUTPUT 719 USING 4A LEOA 150 ENTER 719 USING K Level 160 170 IF ABS Level Expected gt 1 THEN More than 1 dB in error 180 Err 1 190 DISP WARNING Programmed level is more than 1 dB in error 200 END IF 210 220 V SPOLL
313. mpleted However when sending several program codes in the same data string the SOURCE SETTLED bit may be set by one of the other codes For maximum assurance that the Auto Peak is finished an Auto Peak should be performed just before the RF output is to be used in a measurement Once the SOURCE SETTLED bit is set after sending the program code K1 Auto Peak On the RF output is settled and the Auto Peak operation is finished The Signal Generator has several frequencies where mechanical switches are actuated to change the internal microwave signal path When a frequency change crosses one of these switch points the RF output is blanked disabled to eliminate transients of the switching process The actual frequency change will still occur as described above but the RF output will be blanked for approximately 20 milliseconds during the frequency change For this reason frequency changes across one of the switchpoints will require a longer settling time before the output amplitude is settled The various switchpoints are given below 3 73 Operation HP 8673C D Detailed Operating Instructions Freq uency CW cont d Comments cont d Frequency Switch Point glin 2 GHz The microwave signal path is switched for downconversion when switching from above 2 GHz to below 2 GHz 2 GHz A low pass filter is switched in to reduce harmonics 2 0 3 5 GHz 3 5 GHz A low pass filter is switched in at this frequency to reduce harmonics 3 5
314. n Description Equipment Procedure Electrical l Performance Characteristics Characteristics Conditions S Aee FREQUENCY MODULATION Incidental AM lt 5 Rates lt 100 kHz peak deviations lt 1 MHz The Signal Generator is modulated at 5 AM the maximum allowable incidental AM The output signal is detected and measured with a voltmeter The detected signal is recorded as a reference level The Signal Generator is then frequency modulated and _ the detected AM level is compared to the reference level Test Oscillator HP 8116A Digital Voltmeter HP 3456A Crystal Detector HP 8473C 50 Ohm Termination HP 11593A HP 8673C D SYNTHESIZED SIGNAL GENERATOR TEST OSCILLATOR RF 502 OUTPUT OUTPUT mar ar n prar rn rtd CRYSTAL DETECTOR L 500 TERMINATION Figure 4 38 Incidental AM Test Setup fash Connect the equipment as shown in Figure 4 38 2 Set the Signal Generator as follows FREQUENCY ecir aana runi 1000 MHz OUTPUT LEVEL RANGE 0 dB OUTPUT LEVEL VERNIER 0dBm AM switch dice cede eune ae nAi 30 range 3 Set the test oscillator to 10 kHz Adjust the output level for a 5 AM reading on the Signal Generator 4 Record the detected AM level indicated on the digital voltmeter Reference Level n VIMS 4 89 Performance Tests HP 8673C D PERFORMANCE TESTS INCIDENTAL AM cont d Procedure 5
315. n 1 0 dB highest point to lowest point 24 Continue tuning the Signal Generator to 6 6 GHz in 100 MHz steps while observing the power meter readings Maximum power variation must be within 1 5 dB Record the minimum and maximum output power levels in the following table 25 Continue tuning the Signal Generator to 12 8 GHz in 100 MHz steps while observ ing the power meter readings Maximum power variation must be within 2 0 dB Record the minimum and maximum output power levels in the following table 26 Continue tuning the Signal Generator to 18 6 GHz in 100 MHz steps while observ ing the power meter readings Maximum power variation must be within 2 5 dB Record the minimum and maximum output power levels in the following table HP 8673D only 27 Continue tuning the Signal Generator to 26 0 GHz in 100 MHz steps while observ ing the power meter readings Maximum power variation must be within 3 5 dB Record the minimum and maximum output power levels in the following table 4 50 HP 8673C D PERFORMANCE TESTS Performance Tests OUTPUT LEVEL AND FLATNESS TESTS cont d Procedure cont d Frequency Range 0 05 2 0 GHz 0 05 6 6 GHz 0 05 12 3 GHz 0 05 18 6 GHz HP 8673D only 0 05 26 0 GHz Power Variation Maximum Minimum Total Variation Maximum Minimum Total Variation Maximum Minimum Total Variation Maximum Minimum Total Variation Maximum Minimum Total Variation
316. n a leveled pulse To set the Signal Generator for pulse modulation 1 Connect an external pulse source tothe PULSE IN connector and set the frequency of the external pulse source to the desired pulse repetition rate Set the amplitude of the external pulse source to a TTL compatible pulse 0 to 5 volts 2 Press the Signal Generator s PULSE N ORM key if the TTL high level is to be used to turn on the carrier If the TTL high level is to turn off the carrier select pulse complement mode by pressing the PULSE COMPL key Pulse modulation can be programmed to the normal or complement mode using the program codes P2 or P3 respectively The program codes PO and P1 turn off pulse modulation The pulse mode NORM or COMPL cannot be read by the controller The pulse width and pulse repetition rate are set by the external pulse source The controller can interrogate the external source to determine pulse width and repetition rate To pulse modulate the Signal Generator at 1 MHz with a 100 nanosecond pulse width Local 1 Bet the external pulse source for a TTL compatible pulse of 100 nanosecond width at a pulse repetition frequency of 1 MHz 2 Connect the external pulse source to the PULSE IN connector 3 Press the pulse NORM key to activate pulse modulation Remote The programming string for setting pulse normal mode on the Signal Generator is P2 The modulating signal is set by programming the external modulating signal source
317. n of frequency the roundoff error can be reduced to 1 kHz below 18 6 GHz and 2 kHz for frequencies between 18 6 and 26 5 GHz When the sweep start and or stop frequency cannot be set exactly due to frequency resolution a random roundoff occurs To prevent this the remote program can perform a calculation to determine whether the frequency can be set exactly and adjust the desired frequency accordingly If the actual start and stop frequencies are critical setting the start and stop frequency instead of center frequency and delta frequency can be used for greater assurance that the start and stop frequencies are correct To determine whether a frequency can be set to a given value divide the desired frequency in kHz by two if itis between 6 6 and 12 3 GHz by three ifitis between 12 3 and 18 6 GHz or by four if it is above 18 6 GHz If the result is a whole number no remainder the frequency can be set to the desired value For example 16 GHz divided by three itis between 12 3 and 18 6 GHz is 5 333333 33 kHz Since the dividend is nota whole number this frequency cannot be set exactly The nearest frequencies that can be set are 15 999999 GHz 5 8338333X3 and 16 000002 GHz 5 333334X8 Note that the roundoff error is only 1 kHz if 15 999999 GHz is programmed instead of 16 GHz The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The following program is used to set the Signal Generator to the sweep delta fre
318. n open set ups the user must ensure that under these operating conditions the radio fre quency interference limits are met at the border of his premises HEP 8673C D CONTENTS Page Section GENERAL INFORMATION TTG aae bes ke rimmed oleae Ee aA 1 3 Specifications e 1 3 Safety Considerations ere 1 3 Manual Changes Supplement 0000 1 3 Descriptions ea ated R TR aT oie iin ad AR wep oxi 1 3 COS T Za ane e ee e E RE A99 1 4 Electrical Options bias ccwcaupaxeaeses ein dee 1 4 Mechanical Options c cc ee eee eceeeeees 1 4 Accessories Supplied ccc cece ecu cee es 1 4 Equipment Required but not Supplied 1 5 Electrical Equipment Available 1 5 Recommended Test Equipment 1 5 Section Il INSTALLATION PHUPOGUCN ON sesi cose ca eons teehee odes bakes 2 1 Initial Inspection e 2 1 Preparation for Use se devcsarcee cvs annie inde ors 2 1 Front Handles bea ke eawa oda ee 2 1 Power Requirements 0cccceccceceeues 2 1 Line Voltage and Fuse Selection 2 1 Power CADleRs bacon Renee mantedakad Coa wanes a2 2 2 HP IB Address Selection 0 00000 eee 2 3 Interconnections i wiv edocaws sus vedewecsaus 2 4 Mating Connectors datkicscaneke exes dea iasks 2 4 Frequency Reference Sensitivity Selection 2 4 Operating Environment e e ccc cece eee ees 2 4 Bench Oneration saicianiiaetiieenceds
319. n state An alternate preset state is set by another special key sequence To store the current instrument state in one of the nine storage registers 1 Press the STO key to indicate that the current settings are about to be saved in one of the storage registers For system compatible instruments the STO key is a shifted RCL key 2 Press a number corresponding to one of the nine storage registers Any number between 1 and 9 may be used as a storage register Once the key is pressed the instrument state is saved in that register To recall the instrument state from one of the storage registers 1 Press the RCL key to indicate that one of the ten registers is to be recalled The zero register is the preset conditions for the instrument 2 Press one of the numeric keys corresponding to the register that is to be recalled Valid register numbers are 0 through 9 Register 0 the preset register cannot be used to save an instrument state An attempt to store an instrument state in this register will generate an error message If a different set of preset conditions are required one of the nine storage registers may be used to store the alternate preset conditions Pressing RCL and then the backspace key will provide another set of preset conditions see comments The nine storage registers can be used in remote applications If a register is stored in remote mode recalling the register will recall the remote VERNIER setting Local VER
320. n that order The values are not prefixed by program codes and the frequencies are sent in Hz while the dwell time is sent in seconds To sweep from 2 to 4 GHz in manual sweep mode Local 1 Set the start frequency to 2 GHz and the stop frequency to 4 GHz 2 Press the MANUAL SWEEP MODE key to activate manual sweep The key indi cator will light to indicate manual sweep sweep is active Remote The programming string to set manual sweep is W3 The alpha character W can be sent as upper or lower case Program i W3 Manual Sweep Mode IF Increment Frequency Sweep The Signal Generator digital sweep is composed of discrete frequencies that are produced sequentially The minimum step size is limited to the minimum change in frequency that the Signal Generator can produce which is defined as the frequency resolution The number of steps is dependent on the frequency resolution and the frequency span The actual change in output frequency during a sweep will not be uniform for some frequency bands and may vary up to 2 kHz This is required to accommodate sweep step sizes that are not exact multiples of the frequency resolution The sweep steps averaged HP 8673C D Comments Programming Example Operation Detailed Operating Instructions Manual Sweep Mode conta over several sweep points wili be equal to the selected sweep step size An example of the averaging is defining a sweep step size of 10 kHz at a start fr
321. n the Signal Gen erator is in the remote mode and after it has received its first Data message The TLK annun ciator is on when the Signal Generator is currently addressed to talk the LSN annunciatoris on when the Signal Generator is currently addressed to listen The SRQ annunciator is on when the Sig nal Generator is sending the Require Service message The MESSAGE key lights for the same conditions in remote as in local The message can be read in either remote or local when the Signal Generator is under program control Once the message has been read the key light turns off whether or not the causing condition has been corrected The FREQUENCY MHz and RANGE dB dis plays operate in remote mode just as they do in local Hidden parameters can still be displayed in the FREQUENCY MHz display by pressing and holding their front panel keys This capability is not available to the controller since it cannot hold a program code in the same manner that an opera tor can hold down a key However the Output Active Parameter talk function allows the control ler to read the current value of hidden parameters 3 30 Output Level Setting output level is the only front panel feature that is not operated in an identical manner in local and remote modes In local RANGE is set in steps Operation of 10 dB and displayed in the RANGE dB dis play The VERNIER knob sets the intermediate values of output power and is read on the meter In
322. nal to the top graticule line of the display 4 40 HP 8673C D Performance Tests PERFORMANCE TESTS HARMONICS SUBHARMONICS amp MULTIPLES TEST cont d Procedure 4 Tune the Signal Generator to 50 000 MHz The second harmonic now displayed on cont d the spectrum analyzer at 100 000 MHz should be greater than 40 dB below the reference top graticule line lt 40 dBe 5 Repeat steps 2 through 4 for each of the frequencies listed below Use an output level of 3 dBm 0 dBm RANGE to check harmonics and a VERNIER setting of 10 dBm to check subharmonics and multiples Record the measurements in Table 4 3 NOTE This procedure may be repeated for any fundamental frequency of interest within the Signal Generator frequency range The worst case performance for harmonics is at high VERNIER settings while the worst case performance for subharmonics and multiples is at low VERNIER settings Use the appropriate VERNIER seiting for each test Output Harmonic Subharmenic Multiple Frequency Frequency MHz MHz 50 000 100 000 250 000 500 000 500 000 1000 000 1000 000 2000 000 1500 000 3000 000 2000 000 4000 000 4000 000 8000 000 6000 000 12000 000 8000 000 16000 000 10000 000 20000 000 11000 000 22000 000 ra 4000 000 5000 000 5500 000 14000 000 4666 667 16000 000 5333 333 18000 000 6000 000 9333 333 10666 667 12000 9000 5000 000 10000 000 a 15000 0900 5500 000 1
323. nals to the rear panel AUX connector require contact debouncing e g for mechanical switches an internal jumper must be changed The jumper is installed at the factory for electronically clean input signals i e those signals that do not require the use of the debounce circuit The jumper is located on the A2A2 Key Code board To change the jumper position the top cover of the Signal Generator must be removed This task should be performed by service trained persons who are aware of the potential shock hazard of working on an instrument with protective covers removed To avoid hazardous electrical shock the line mains power cable should be disconnected before removing the Signal Generator s cover The following procedure describes how to locate and change the jumper position a Set the LINE switches to STBY and Off Disconnect the line power cables b Remove the Signal Generator s top cover by removing the two plastic feet from the rear of the top cover and loosening the screw at the middle of the rear edge of the top cover c Remove the A2A2 Key Code board by gently lifting the board s extractors the extractors are color keyed red and black d The jumper is located on the center of the board e To enable the debounce circuit remove the jumper from W2 and reinstall the jumper at W1 f Reinstall the A2A2 Key Code board and the Signal Generator s top cover Figure 2 5 AUX Interface Connector 2 7 2 8 HP 8673C
324. ncies between 18 6 and 26 5 GHz When the Signal Generator is programmed to a frequency that cannot be set exactly due to frequency resolution a random roundoff occurs To prevent this the remote program should perform a calculation to determine whether the frequency can be set exactly and adjust the desired frequency accordingly To determine whether a frequency can be set to a given value divide the desired frequency in kHz by two ifit is between 6 6 and 12 3 GHz by three if itis between 12 3 and 18 6 GHz or by four if it is above 18 6 GHz If the result is a whole number no remainder the frequency can be set to the desired value For example 16 GHz divided by three itis between 12 3 and 18 6 GHz is 5 333333 33 kHz Since the dividend is not a whole number this frequency cannot be set exactly The nearest frequencies that can be set are 15 999999 GHz 5 333333X3 and 16 000002 GHz 5 333334X3 Note that the roundoff error is only 1 kHz if 15 999999 GHz is programmed instead of 16 GHz For applications that require fastest execution the SOURCE SETTLED bit of the status byte can be used Once the bit is set after a frequency has been programmed the output is valid and the program may continue If the frequency is programmed and the status byte is not checked the program should wait at least the frequency switching speed time before assuming the output valid If the status byte is to be used to monitor settling the program string t
325. ncy in 1 5 MHz steps Locai 1 Press the FREQ INCR key 2 Keyin 1 5 using the numeric keypad The FREQUENCY MHz display should show 1 5 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the MHz units key to finish the sequence The FREQUENCY MHz display will show the entered frequency increment until the units key is released The entry should now be right justified 4 Turn the TUNE knob clockwise or press the FREQ INCREMENT up key to incre ment the frequency in 1 5 MHz steps Turn the TUNE knob counter clockwise or press the FREQ INCREMENT down key to decrement the frequency in 1 5 MHz 3 77 Operation HP 86738C D Detailed Operating Instructions Frequency Increment and Tuning conta Example steps Note that an error is not indicated if an attempt is made to tune the frequency conta 5 above or below the frequency range of the Signal Generator Phe heres increment could also have been entered as 0015 GHz or 1500 kHz The only difference is the placement of the decimal point and the units key pressed after the frequency increment has been entered using the numeric keypad Remote _ The programming string for setting the frequency increment is composed of a program code numeric data and the units terminator The frequency increment may be pro grammed in units of GHz MHz kHz or Hz To program the Signal Generator for a 1 5 MHz frequency increment the possibl
326. nd 26 5 GHz can be set within 4 kHz of the desired frequency However with careful selection of fre quency the roundoff error can be reduced to 1 kHz below 18 6 GHz and 2 kHz for frequencies between 18 6 and 26 5 GHz When the Signal Generator is programmed to a frequency that cannot be set exactly due to frequency resolution a random roundoff occurs To prevent this the remote program should perform a calculation to determine whether the frequency can be set exactly and adjust the desired frequency accordingly To determine whether a frequency can be set to a given value divide the desired frequency in kHz by twoifitis between 6 6 and 12 3 GHz by three ifitis between 12 3 and 18 6 GHz or by four if it is above 18 6 GHz If the result is a whole number no remainder the frequency can be set to the desired value For example 16 GHz divided by three itis between 12 3 and 18 6 GHz is 5 333333 33 kHz Since the dividend is nota whole number this frequency cannot be set exactly The nearest frequencies that can be set are 15 999999 GHz 5 3333833X3 and 16 000002 GHz 5 3833334X3 Note that the roundoff error is only 1 kHz if 15 999999 GHz is programmed instead of 16 GHz Reading the sweep center frequency will not indicate frequency rounding The programmed frequency is saved for used in calculating the appropriate sweep start and stop frequencies To avoid errors during this calculation due to roundoff the sweep center frequency is saved
327. nd actual level Measured d Bee Correction 1 3 dB Actual Lavel dBe 20 Set the spectrum analyzer controls for a resolution bandwidth of 3 Hz and a frequency span per division of 20 Hz Using a 3 Hz resolution bandwidth requires a 6 06 dB correction factor 21 Repeat steps 3 through 19 while observing the noise 100 Hz from the carrier Record the results in the table below eee 2000 MHz 6 06 dB lt 70 dBe 6600 MHz lt 70 dBc 12 300 MHz lt 64 dBe 18 600 MHz lt 60 dBe 26 000 MHz lt 68 dBe 4 37 Performance Tests HP 8673C D PERFORMANCE TESTS tt SINGLE SIDEBAND PHASE NOISE TEST cont d Procedure 22 Contd 23 24 25 26 27 28 29 30 bl 32 33 34 4 38 Set the spectrum analyzer resolution bandwidth to 30 Hz and frequency span per division to 200 Hz The 30 Hz bandwidth requires 16 06 dB correction Tune the Signal Generator to 1 999 800 MHz Tune the local oscillator to 2 000 000 MHz Adjust the spectrum analyzer to place the 200 kHz IF signal at the left edge of the display Set the spectrum analyzer controls to place the peak of the signal at the top graticule line Increase the log reference level control to move the peak of the IF signal 20 dB above the top graticule line The top graticule line is now 20 dBc Observe the noise level 1 kHz from the carrier The displayed level should be great
328. nd verify that the Signal Generator frequency display changes to 18 600 000 MHz Verify also that the frequency counter reading agrees within 1 count 18 599 995 GHz frequency resolution 3 kHz WW LAT Band 4 Test HP 8673D only 13 14 15 16 Tune the Signal Generator to 25 999 996 MHz and set the frequency increment FREQ INCR to 1 kHz Tune the frequency down one increment and verify that the Signal Generator frequency display indicates 25 999 992 MHz and the frequency counter reading agrees within t 1 count Tune the frequency up two increments and verify that the Signal Generator frequency display changes to 26 000 000 MHz Verify also that the frequency counter reading agrees within 1 count 25 999 996 GHz frequency resolution 4 kHz ___ Disconnect the frequency counter and replace the FREQ STANDARD jumper between A3J9 and A3J10 Set the FREQ STANDARD INT EXT switch to INT 4 25 HP 8673C D Performance Tests PERFORMANCE TESTS 4 9 INTERNAL TIME BASE AGING RATE Specification Electrical Performance Conditions Characteristics Characteristics FREQUENCY Reference Oscillator Frequency 10 MHz After a 10 day warmup 246 typically 24 hours in a Aging Rate lt 5x10 day normal operating environment Accuracy and Stability Same as reference oscillator A reference signal from the Signal Generator 10 MHz OUT is connected to the oscillo scope s vertical input A frequen
329. ndicate maximum available output power This should only occur when output levels above the specified maximum leveled power are set For example if the RF output level is set to 13 dBm and the level meter reads 4 dBm with the ALC UNLEVELED annunciator lighted only 6 dBm of output power is available at that frequency The Signal Generator accepts any RF output level between 101 9 and 13 dBm RF output levels above the specified maximum leveled power may not be available at all frequencies Programming the RF output level can be done in one of two ways The RF output level can be programmed directly using the program code LE AP or PL The units terminator for the output level is dBm which corresponds to the program code DM The Signal Generator will also accept the program code DB as the terminator When programming the RF output level the VERNIER is set between 0 and 9 9 dBm and the RANGE is set accordingly The RF output level can also be programmed by programming the VERNIER and the RANGE separately The program code to set the RANGE is RA and the program code to setthe VERNIER is VE The units terminator for both codes can be either DB or DM The output active program code suffix can be used to read the current values of the RANGE VERNIER or the RF output level directly To read the RANGE setting send the program codes RAOA and then read the RANGE setting The Signal Generator will send the RANGE in fundamental dBm units If th
330. nds 10 SUB Sweep_dwell Err Expected Dwell in milliseconds 20 OUTPUT 719 USING 2A MG Clear message from 8673 30 ENTER 719 USING 2A Message to clear any old messages 40 OUTPUT 719 USING 2A DDD 2A SP Expected SS 1 Set size 50 OUTPUT 719 USING 2A MG Get any error message 60 ENTER 719 USING 2A Message 70 SELECT VAL Message 80 CASE 8 90 Err 1 100 DISP WARNING The specified dwell time is out of range 110 CASE ELSE 120 Err 0 130 END SELECT 140 150 SUBEND The following message numbers may be displayed when setting the sweep dwell time Each message is explained as it pertains to setting the dwell time For a more complete description of the messages see the MESSAGES detailed operating instructions 08 The entered dwell time is not within the range of 1 millisecond to 255 milliseconds 3 69 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure 3 70 Frequency CW When sweep modes are off the Signal Generator can be set to any frequency within its range The frequency can also be tuned in any step size that will result in a new frequency within its specified range All valid frequencies can be remotely programmed or entered manually via the numeric keypad or tuning controls For applications requiring setting a single specific frequency direct entry using the numeric keypad is the most efficient method However
331. nel SRQ indicator will be lighted whenever this bit is set in local or remote mode The HP IB service request will also be generated in remote or local mode CHANGE IN SWEEP PARAMETERS Changing the CW frequency will reset the start and stop frequencies of the sweep Any changes to start or stop frequencies delta frequency number of steps or step size dwell time or center frequency will set this bit Extended Status Byte The extended status byte is read by sending the OS program code to the Signal Generator and then reading the status byte and extended status byte The bits in the extended status byte are set whenever a valid condition exits The only way to clear a bit that has been set is to clear the status bytes with a CS program code or to read the extended status byte Once the extended status byte is read it will be cleared and updated Note that the bits are not cleared until after the extended status is read To read the current instrument extended status the program string CSOS should be sent to clear both status bytes and to update the extended status byte The extended status byte is composed of eight bits with each bit defined as follows HP 8673C D Description contd Local Procedure Remote Procedure Operation Detailed Operating Instructions Status Byte and Polling conta BIT 1 SELF TEST FAILED When the Signal Generator is first turned on a self test is performed to check the instrument s Digit
332. ng Instructions Description Local Procedure 3 52 Auto Sweep Mode The Signal Generator performs a digital sweep by stepping the RF output frequency in discrete steps from the start frequency to the stop frequency The number of steps that the Signal Generator produces between the start and stop frequency is controlled by the number of steps or the sweep step size parameters The time that the Signal Generator remains at each step after switching frequencies is controlled by the dwell time parameter The Signal Generator has three sweep modes to accommodate a variety of applications Auto sweep mode is used when a repetitive sweep is required Auto sweep mode will step the RF output frequency from the start frequency to the stop frequency and then repeat the sweep until the sweep is turned off or a band crossing is encountered Single sweep mode will step the RF output frequency from the start frequency to the stop frequency once and then stop This mode is useful when a single sweep is taken during a measurement where the measuring device can store the results Manual sweep provides a convenient method to limit the tuning range of the frequency tuning controls In applications requiring a single band of frequencies the tuning limits can be set to cover the band of interest which allows the user to tune the frequency without having to watch the Signal Generator display to determine when the frequency is outside of the selected band Th
333. ng VEOA and then read the VERNIER setting using the ENTER command The Signal Generator will send the VERNIER setting in units of dBm If the setting is read as a string the format will be the program code VE followed by the VERNIER setting in dBm and then the units code DM Example To set the Signal Generator to power meter leveling over the range of 10 to 0 dBm using a 10 dB coupler Local 1 Connect the directional coupler to the point where the RF power is to be leveled Connect the power meter sensor to the coupled port of the 10 dB directional coupler 2 Press the ALC INT key to place the Signal Generator into internal ALC mode 3 Set he RF output level for a 15 dBm power meter reading on the power meter Allow the power meter to auto range to the coupled power 15 dBm Once the power meter has stabilized press the RANGE HOLD key or set the range manually to prevent auto ranging The power meter should now be set to read power levels of 20 to 10 dBm on the set range 3 111 Operation HP 8678C D Detailed Operating Instructions Example cont d Program Codes L HP 1B Comments 3 112 Power Meter Automatic Level Control conta 4 Pressthe ALC PWR MTR key on the Signal Generator and set the Signal Generator range to 10 dB The ALC UNLEVELED annunciator may come on when the power meter leveling mode is activated The calibration in the next step will eliminate this indication 5 Adjust the
334. ng condition has been corrected Output Active Parameter This function allows the user to determine the present value of a specific parameter After receiving the program code for a value selectable parameter followed by the pro gram code OA Output Active and when ad dressed to talk the Signal Generator will output a string over the bus consisting of the following Selected Program Code Current Numeric Value Units Terminator LF and EOT Any parameter that has a numeric value associated withit can be interrogated An exception to this output format is Steps When the controller sends SPOA the Signal Generator returns with the string SP Step Size HZ SP Number of Steps SS LF and EOI The Signal Generator may output a program code that differs from the code sent to it by the con troller For example the Signal Generator re sponds with the program code CF center fre quency when sent FR frequency and MK mar ker when sent M1 M2 M3 M4 or M5 Markers 1 through 5 3 37 Operation Funetion Program Code Front Panel Learn Mode L1 ae oana Special Function Learn 12 Mode Message Output Active Parameter Program Code OA Output Sweep Steps Step Size Table 3 4 Talk Functions Signal Generator Ouiput Response to Program Code 96 Binary Bytes EOL 26 Binary Bytes EOI 2 Digits LF and EOT Program Code Numeric Value Units Terminator LF and KOL SP Ste
335. nly and Listen Only are used when the Signal Generator is in a master slave configuration See the Detailed Operating Instructions in Section IIT for more information HP IB ADDRESS FRONT PNL ENABLE fe ADDRESS uas Te TALK ONLY af v m k l l Figure 2 3 HP IB Address Switch Shown as Set by the Factory 2 3 Installation HP IB Address Selection cont d f To confirm the address setting turn on the Signal Generator and press and hold the LOCAL DISPLAY ADDRESS key on the front panel The current HP IB address will be displayed in decimal in the FREQUENCY MHz display g Replace the A2 Assembly s internal cover and the Signal Generator s top cover Replace the two plastic standoffs h Connect the line mains power cables to the Line Power Modules and set the LINE switches to ON Front Panel HP IB Address Setting To set the Sig nal Generator s HP IB address from the front panel the FRONT PNL ENABLE switch on the HP IB address switch must be set to 1 To change the address from the front panel key in the desired address press the STO key then press the LOCAL key Refer to Remote Operation HP IB in Section III for additional information 2 9 Interconnections Interconnection data for the Hewlett Packard Inter face Bus is provided in Figure 2 4 2 10 Mating Connectors HP iB interface Connector The HP IB mating connector is shown in Figure 2 4 AUX Interface Connector The rear
336. nly defined for system compatible instruments See paragraph 3 2 System Compatibility for more information 90 Auto Peak malfunction This indicates that the instrument may require service 3 75 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure 3 76 Frequency Increment and Tuning The Signal Generator frequency can be tuned in any tuning increment that will result gt y in new frequency within its specified range The tuning increment is set with the FREQ INCR key and the numeric keypad All valid frequency increments may be remotely programmed or entered manually via a numeric keypad Tuning the Signal Generator frequency is accomplished using the FREQ INCREMENT up and down keys or the TUNE knob The tuning increment size for both methods is equal to the frequency increment value except during manual sweep mode The sweep step size controls the tuning increment in manual sweep mode Tuning with the TUNE knob is useful for observing a range of frequencies and still being able to speed up or slow down the tuning as desired In addition the frequency increment may be decreased if finer resolution is desired around a specific frequency The TUNE knob can be disabled to avoid accidental changes in the set frequency The frequency increment step keys are very useful for tuning between channels with a fixed channel spacing Setting the frequency increment to the channel spacing all
337. ns must be met a The Signal Generator must havea l hour warmup for all specifications b The line voltage must be 100 120 220 or 240 Vac 5 ol 0 c The ambient temperature must be 15 to 35 C for Harmonically Related Spurious signals RF Output Level Pulse Peak Level Accuracy and Amplitude Modulation tests 0 to 55 C for all other tests 4 2 ABBREVIATED PERFORMANCE TEST In most cases it is not necessary to perform all of thetestsin this section Paragraph 4 7 contains the abbreviated performance tests These tests can be used for operation verification Results of these tests may be recorded in Table 4 1 Abbreviated Performance Test Record These tests can also be used for incoming inspec tions and preventative maintenance They are not intended to be a complete check of specifications but will provide 90 confidence that the Signal Generator is meeting its major performance speci fications These tests can be performed with less time and equipment than the full Performance Tests 4 3 CALIBRATION CYCLE This instrument requires periodic verification of performance to ensure that it is operating within specified tolerances The performance tests de scribed in this section should be performed at least once each year under conditions of heavy usage or severe operating environments the tests should be more frequent Adjustments that may be re quired are described in Section V Adjustments Annual and bi
338. nt in these tests Equipment Local Oscillator HP 8340A Spectrum Analyzer HP 3585A INET ROP 7 d oe acs eee eco ncn RHG DMS1 26 Procedure 1 Connect the equipment as shown in Figure 4 17 4 35 Performance Tests HP 8673C D PERFORMANCE TESTS SINGLE SIDEBAND PHASE NOISE TEST cont d Procedure HP 8673C D SYNTHESIZED SPECTRUM ANALYZER cont d SIGNAL GENERATOR LOCAL OSCILLATOR INPUT RF OUTPUT RF OUTPUT Figure 4 17 Single Sideband Phase Noise Test Setup NOTE Connect the mixer directly to the local oscillator to avoid any power loss 2 Set the spectrum analyzer s start frequency to 40 kHz resolution bandwidth to 1 Hz and frequency span per division to 5 Hz 3 Tune the Signal Generator to 1 999 960 MHz Set the RANGE to 20 dB Set the VERNIER to 0 dBm as read on the front panel meter 4 Tune the local oscillator to 2 000 000 MHz with an output amplitude 8 dBm 5 Set the spectrum analyzer controls so that the peak of the 40 kHz signal is at the top graticule line 6 Observe the noise level 30 Hz from the carrier The displayed level should be greater than 62 7 dB below the carrier lt 62 7 dBc Record the measured and actual level after correction Measured dd Bee Correction 1 3 dB Actual Level Ww d Bee 7 Tune the Signal Generator to 6600 MHz with an output amplitude of 20 dBm 8 Tune the local oscillator to 6599 960 MHz wit
339. nto 6000 nominal AM depth is linearly controlled by varying input level between 0 and 1V peak 100 Hz to 10 kHz rates 100 Hz to 10 kHz rates 100 Hz to 10 kHz rates 30 depth 0 05 to 6 6 GHz gt 6 6 to 12 8 GHz gt 12 3 to 18 6 GHz gt 18 6 to 24 0 GHz gt 24 0 to 26 0 GHz 30 and 100 kHz V ranges 03 1 3 and 10 MHz V ranges 0 05 to 6 6 GHz gt 6 6 to 12 8 GHz gt 12 3 to 18 6 GHz gt 18 6 to 26 0 GHz All ranges peak deviation is linearly controlled by varying input level between 0 and 1 Vpk 100 kHz rate 100 kHz rate Rates lt 100 kHz peak deviations lt 1 MHz HD 8673C D Electrical Characteristics DIGITAL SWEEP Sweep Function Sweep Modes Step Size Dwell Time Maximum Sweep Width Markers REAR PANEL AUXILIARY CONTROL CONNECTOR 14 Pin Connector Input Required Outputs Table 1 1 Specifications 6 of 7 Start Stop or Center Frequency AF Span Sweep Manual Auto Single Maximum equals the maximum sweepspan minimum is equal to the greater of the fre quency resolution or span divided by 9999 Set from 1 to 255 ms per step Auto Sweep is restricted to amplifier filter bands shown Manual and Single Sweep modes are limited to the frequency range of the Signal Generator including overrange MANUAL mode Single Sweep 0 01 to 18 6 GHz HP 8673C 0 01 te 26 5 GHz HP 8673D 5 independent fixed frequency markers set from front panel Inputs Stop Sweep HP 8
340. ntroller can monitor the SWEEP DONE bit of the extended status byte to determine when the sweep is finished The bit will be set when the stop frequency is reached and will not be reset until it is read or the status byte is cleared The output couple program code OC can be used to read the start frequency center frequency and dwell time in that order The three values are not prefixed by program codes and the frequencies are sent in Hz while the dwell time is sent in units of seconds To perform a single sweep from 2 to 4 GHz Local 1 Set the start frequency to 2 GHz and the stop frequency to 4 GHz 2 Press the SINGLE SWEEP MODE key to arm the single sweep The key indicator will light to indicate that single sweep mode has been selected 3 Press the SINGLE SWEEP MODE key again to execute the sweep Once the sweep is finished the single sweep will be rearmed in preparation for another sweep Remote The programming string to perform a single sweep is W6 The alpha character W can be sent as upper or lower case The sweep can be armed and then executed later using the W4 or W5 program codes followed by a W4 program code when the sweep is to be executed Using the W5 program code alway ensures that a single sweep is armed and does not execute immediately If the single sweep mode is armed when a W4 program code is received the sweep will execute Program Code Function W4 Single Sweep Arm or Execute W5 Single Sweep Arm
341. ny number of sweep steps between 1 and 9999 steps The programmed value may be adjusted as required to be consistent with the remain ing sweep parameters and the frequency resolution The format of the remote programming follows the front panel key sequence The program code SS or SP is sent followed by the desired number of steps and the units SS HP 8673C D Remote Procedure cont d Example Program Codes Comments Operation Detailed Operating Instructions Steps Sweep conra The programmed number of steps can be read by the controller using the output active program code suffix To read the current number of steps the program string SPOA or SSOA is sent and then the step size and the number of steps must be read Since step size and the number of steps are directly related both are sent when the output active program code suffix is used If read as a string the format is the program code SP followed by the sweep step size in fundamental units Hz the units terminator Hz a comma the program code SP followed by the current number of steps and the units terminator SS To set the number of sweep steps to 350 steps Locai 1 Press the STEP key 2 Key in 350 using the numeric keypad The FREQUENCY MHz display should show 350 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the STEP units key to finish the sequence The FREQUENCY MHz display should s
342. o lt 2 0 GHz 2 0 to lt 16 0 GHz 16 0 to 18 6 GHz 16 0 to 26 0 GHz 2 0 to lt 16 0 GHz 16 0 to 18 6 GHz 16 0 to 26 0 GHz In the 21 to 22 GHz frequency range 3 4 mode subharmonics 15 75 to 16 5 GHz may exist lt 50 dBe In the 0 05 to lt 2 0 GHz band carrier frequency independent spurious outputs may exist in the gt 50 MHz to 100 MHz range at lt 55 dBc and in the 10 MHz to 50 MHz range at lt 40 dBc 1 7 General KO HP 8673C D Table 1 1 Specifications 3 of 7 Performance Limits Conditions Electrical Characteristics RF OUTPUT cont d Option 001 Delete attenuator Leveled Output 12 dBm to 10 dBm 0 05 to lt 2 0 GHz Normal Mode 7 dBm to 10 dBm 2 0 to lt 16 0 GHz AP 8673 4 dBm to 10 dBm 16 0 to 18 6 GHz HP 8673D 9 dBm to 10 dBm 16 0 to 26 0 GHz Bypass Mode 10 dBm to 10 dBm 2 0 to lt 16 0 GHz HP 8673C 7 dBm to 10 dBm 16 0 to 18 6 GHz HP 8673D 10 dBm to 10 dBm 16 0 to 26 0 GHz Option 004 Rear panel output Leveled Output 10 dBm to 100 dBm 0 05 to lt 2 0 GHz Normal Mode 4 dBm to 100 dBm 2 0 to lt 16 0 GHz HP 8673 1 dBm to 100 dBm 16 0 to 18 6 GHz HP 8673D 4 dBm to 100 dBm 16 0 to 26 0 GHz Bypass Mode 7 dBm to 100 dBm 2 0 to lt 16 0 GHz HP 8673C 4 dBm to 100 dBm 16 0 to 18 6 GHz HP 8673D 5 dBm to 100 dBm 16 0 to 26 0 GHz Option 005 Options 001 amp 004 Leveled Output 12 dBm to 10 dBm 0 05 to lt
343. o 1 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level 300 Hz 1 kHz offset DU dBe 9 Set the spectrum analyzer frequency span to 5 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level gt 1 kHz offset __ _ lt 65 dBe 10 Tune the Signal Generator to 3000 000 MHz 11 Tune the local oscillator to 3000 020 MHz 12 Set the spectrum analyzer frequency span to 500 Hz Adjust the spectrum analyzer controls to place the peak of the 20 kHz IF signal on the top graticule line Verify that the line related harmonics of the Signal Generator do not exceed the values shown below Record the highest spurious signal level in each offset band 2 0 6 6 GHz lt 300 Hz offset ss lt 50 dBc 4 45 Performance Tests HP 86738C D PERFORMANCE TESTS POWER LINE RELATED SPURIOUS SIGNALS TESTS cont d Procedure 183 Contd 14 15 16 17 18 19 20 21 22 23 Set the spectrum analyzer frequency span to 1 kHz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level 300 Hz 1 kHz offset lt 60 dBe Set the spectrum analyzer frequency span per division to 500 Hz Ensure that the start frequency is 20 kHz Measure and record the highest spurious signal level gt 1 kHz offset 000 lt 65 dBe Tune the Signal Generator to 7000 MHz Tune the local osci
344. o kHz lt fx 20 log 00 kHz where dB the calculated frequency response Vx the voltage measured at fx V100 kHz the reference voltage measured at 100 kHz fx the measured frequency 4 85 Performance Tests HP 86738C D PERFORMANCE TESTS 4 25 EXTERNAL FM ACCURACY AND METER ACCURACY Specification Electrical Performance Conditions Characteristics Characteristics FREQUENCY MODULATION Maximum Peak Deviation The smaller of 10 MHz or 0 05 to 6 6 GHz i modi x 5 The smaller of 10 MHz or 6 6 to 12 3 GHz f mod x 10 The smaller of 10 MHz or 12 3 to 18 6 GHz f mod x 15 HP 8673D only The smaller of 10 MHz or 18 6 to 26 0 GHz f mod x 20 Sensitivity Maximum input 1 Vpk All ranges peak deviation is peak deviation per Vpk into 500 nominal linearly controlled by varying input level between 0 and 1 Vpk Indicated Meter Accuracy 12 of reading 100 kHz rate 3 of range Accuracy Relative to 7 of reading 100 kHz rate External FM Input Level 3 of range Description The Signal Generator is frequency modulated by an external source The output of the Signal Generator is mixed with a local oscillator to produce a modulated 500 MHz IF signal A measuring receiver measures the FM characteristics of the IF signal Equipment Local Oscillator igs HP 8340A Measuring Receiver HP 8902A Test Oscillator Z HP 8116A Digital Voltmeter HP 3456A Mixer yes sas espe beer
345. ocal Procedure contd Remote Procedure Example Operation Detailed Operating Instructions Diode Automatic Level Control conta 6 Adjust the ALC CAL control on the Signal Generator front panel until the UNLEVELED annunciator is extinguished Set the Signal Generator VERNIER for a 0 dBm indication on the Signal Generator s LVL meter Continue adjusting the CAL control until the power meter indicates the desired level For example fora desired level in the range of 17 to 10 dBm using a 20 dB directional coupler adjust the CAL control for a power meter reading of 10 dBm Once the calibration is complete the level at the output of the directional coupler can be varied over a 3 to 10 dB range Ifturning the CAL control fully clockwise does not have sufficient range to calibrate the output level set the range higher until the calibration can be completed If the output level cannot be set low enough step the RANGE down until the cali bration can be performed as per this step Using the highest range will provide the best compensation for increasing losses higher power levels at the Signal Gen erator output Using a lower range will provide the best compensation for decreas ing losses See the comments section for more information on selecting the optimum range The equipment setup for remote control of diode leveling 1s the same as the local procedure However the calibration must be performed manually The program
346. ocedure Electrical Performance Characteristics Characteristics Conditions INCIDENTAL FM 100 Hz to 10 kHz rates 30 depth lt 4 kHz 0 05 to 6 6 GHz lt 8 kHz 6 6 to 12 3 GHz lt 12 kHz 12 3 to 18 6 GHz HP 8673D only lt 16 kHz 18 6 to 24 0 GHz lt 25 kHz 24 0 to 26 0 GHz Incidental FM is measured using a measuring receiver The output of the Signal Generator is amplitude modulated An AM reference level is set on the measuring receiver The modulation analyzer is then set to measure FM The amount of incidental FM present on the signal is measured and recorded Local Oscillator HP 8340A Measuring Receiver HP 8902A Audio Analyzer Source HP 8903B Miker 25 cee octane eaae RHG DMS 1 26 6 dB Attenuator HP 8493C Option 006 HP 8673C D SYNTHESIZED SIGNAL GENERATOR MEASURING RECEIVER RF OUTPUT ATTENUATOR a Figure 4 34 Incidental FM Test Setup Part One 1 Connect the equipment as shown in Figure 4 34 2 Set the Signal Generator as follows FREQUENCY Gelsciageeiane cada cs 200 MHz OUTPUT LEVEL RANGE 0dB OUTPUT LEVEL VERNIER 0 dBm ALC GREE CRISS ES CURE REE INT AM Ad ARR te ee ROR 100 range EM eese einer cee a a e re yeas OFF 3 Select AM mode on the measuring receiver 4 81 Performance Tests HP 8673C D PERFORMANCE TESTS INCIDENTAL FM cont d Procedure 4 Tunethe modulation source to 10 kHz Adjust the o
347. of frequency modulation Messages 3 85 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure Remote Procedure Example 3 86 Internal Automatic Level Control Automatic Leveling Control ALC is used to maintain a constant power level ata given point Internal ALC provides a leveled output signal at the RF output connector thatis held constant over the entire frequency range of the instrument Internal ALC is the simplest mode to operate and requires no additional equipment to use The RF output level is controlled over the entire frequency range of the instrument with adynamic range of 100dBm upto a maximum of 13 dBm The actual maximum leveled power is dependent on RF output frequency and is specified within frequency bands To level the RF output over the entire frequency range of the Signal Generator the output level must be set no higher than the maximum leveled power of the lowest power frequency typically the highest frequency To set the Signal Generator for internal leveling 1 Press the Signal Generator ALC INT key to set the ALC circuitry to detect the RF output power internally 2 Set the OUTPUT LEVEL RANGE and the OUTPUT LEVEL VERNIER so the sum of the RANGE display and the LEVEL meter equal the desired output power Stepping the range up or down allows the output level to be changed in 10 dB steps Adjusting the vernier enables the output level to be changed continuousl
348. oller must send the Signal Generator s listen address an Abort message a new talk address or a universal untalk command Talk Functions The types of information that the Signal Generator can send in a Data message are Front Panel Learn Mode Special Function Learn Mode Messages Output Active Parameter Output Couple Output Lock Frequency Test Interface Output Status Output Request Mask Value explained later under Sending the Request Mask Value B e eooo Each function is enabled by first addressing the Signal Generator to listen Then the Signal Gen HP 8673C D Sending the Data Message contd erator must receive a Data message with the appropriate program code When the Signal Gen erator is addressed to talk it will output data for the selected talk function If the controller does not repeat the program code or send a new one the Signal Generator sends data for the last selected talk function when it is addressed to talk How ever it is recommended that a talk function pro gram code be sent each time prior to addressing the Signal Generator to talk This will ensure that the Signal Generator sends the appropriate data Refer to Table 3 4 for a summary of talk functions Front Panel Learn Mode The front panel learn mode uses the controller s memory to learn and store a data string that describes the Signal Gen erator s current front panel setting Once an instru ment state has been learned th
349. ollowing table Tune the Signal contd Generator s output frequency as shown for each level Measure rise time fall time overshoot and ringing at each setting Rise and fall times should be less than 40 ns Overshoot and ringing should be less than 25 Record the measurements in the following table OUTPUT LEVEL FREQUENCY FAL Overshoat VERNIER Miz and Ringing 10 dB 5dBm 12 300 003 0dB 0dBm 12 300 003 0dB 0dBm 17990 003 0dB 0dBm 19 590 003 0 dB 10 dBm 12 300 003 0 dB 10 dBm 17 990 003 0 dB 10dBm 18 590 003 HP 8673C 0 dB 2dBm 17 990 003 0 dB 2dBm 18 590 004 HP 8673D 10 dB 4 dBm 17 990 003 10 dB 4 dBm 18 590 004 17 Tune the Signal Generator from 12 3 to 18 6 GHz at output eas of 10 dBm 0 dBm and maximum power The maximum power level changes at 16 GHz as follows HP 8673C 2 dBm HP 8673D 6 dBm Verify that the rise and fall times are less than 40 ns and overshoot and ringing are less than 25 Record the worst case readings in the following table FREQUENCY OUTPUT LEVEL La FALL Overshoot MHz RANGE HJ S ns ns and Ringing HP 8673C HP 8673D HP 8673D only 18 Set the Signal Generator to the levels shown in the following table Tune the Signal Generator s output frequency as shown for each level Measure rise time fall time overshoot and ringing ateach setting Rise and fall times should bo less than 40 ns Overshoot and ringing s
350. omplete the level at the output of the directional coupler can be varied over a 3 to 10 dB range If turning the CAL control fully clockwise does not have sufficient range to calibrate the output level set the range higher until the calibration can be completed If the output level cannot be set low enough step the RANGE down until the calibration can be performed as described in this step Using the highest range will provide the best compensation for increasing losses higher power levels at the Signal Generator output Using a lower range will provide the best compensation for decreasing losses See the comments section for more information on selecting the optimum range Remote The equipment setup for remote control of power meter leveling is the same as the local Procedure procedure However the calibration must be performed manually The program code for power meter ALC is C3 Once the calibration is complete the level can be remotely controlled by programming the VERNIER to the appropriate level Changing the range while using external power meter leveling will have no affect on the level but can force the Signal Generator to lose control of the level due to insufficient attenuation lack of ALC dynamic range or too much attenuation attempted operation beyond maximum power specification The VERNIER setting can be read by the controller using the output active program code suffix To read the VERNIER setting send the program stri
351. on These checks can be performed together or separately Any special requirements for a check are described at the beginning of the check The test setup is the same for all of the checks Connect the Signal Generator to the bus controller via the HP IB interface HP IB Controller vedo as HP 85B 829038A 16K Memory Module 00085 15005 Advanced Programming ROM HP IB Interface 0 0000 HP 82937A NOTE Any HP 9000 series 200 or series 300 controller with an HP IB interface and BASIC operating system can be used for this check Remote and Local Messages and the LOCAL Key Note This check determines if the Signal Generator properly switches from local to remote control from remote to local control and if the LOCAL key returns the instrument to local control If the Signal Generator is in remote mode that is the front panel RMT annunciator is on switch the instrument to STBY then to ON 3 24 HP 8678C D Operation OPERATOR S CHECKS HP IB Functional Checks cont d Description Series 200 300 HP 858 BASIC Send the Remote message by setting Remote Enable REN true and addressing the Signal Generator to listen TENN e ee REMOTE 719 REMOTE 719 Operator s Check that the Signal Generator s RMT and LSN annunciators are on Response Send the Local message to the Signal LOCAL 719 LOCAL 719 Generator Operator s Check that the Signal Generators RMT annunciator is off but its
352. onger settling time before the output amplitude is settled The various switch points are given in the following table HP 8678C D Operation Detailed Operating Instructions Frequency Increment and Tuning conta Comments cont d Frequency E Switch Point poser ping 2 GHz The microwave signal path is switched for downconversion when switching from above 2 GHz to below 2 GHz 2 GHz A low pass filter is switched in to reduce harmonics 2 0 3 5 GHz 3 5 GHz A low pass filter is switched in at this frequency to reduce harmonics 3 5 6 0 GHz 6 0 GHz A tracking bandpass filter is switched in from 6 to 22 GHz 18 6 for the HP 8673C to reduce harmonics and subharmonics above 6 6 GHz 16 0 GHz An amplifier is switched in to increase output power above 16 GHz HP 8673D only 22 0 GHz A high pass filter is switched in to reduce subharmonics HP 8673D only Programming The following programs are written in BASIC for HP 9000 Series 200 or 300 controllers Example The following program is used to step the Signal Generator from Start to Stop in Step increments A subroutine called Read_power is called after each frequency increment 10 SUB Freq_step Err Start Stop Step t Frequencies in MHz 20 CALL Freq_set Err Start Sub under CW Frequency 30 OUTPUT 719 USING 2A 5D DDD 2A Fl Step MZ 40 IF STOP START lt 0 THEN 50 P_code DN Decrement from Start to Stop 60 ELSE 70 P_code UP 80 END IF 90 10
353. or a period of one year from date of shipment During the warranty period Hewlett Packard Company will at its option either repair or replace products which prove to be defective For warranty service or repair this product must be returned to a service facility designated by HP Buyer shall prepay shipping charges to HP and HP shall pay shipping charges to return the product to Buyer However Buyer shall pay all ship ping charges duties and taxes for products returned to HP from another country HP warrants that its software and firmware designated by HP for use with an instrument will execute its programming instructions when properly installed on that instrument HP does not warrant that the operation of the instrument or software or firmware will be uninterrupted or error free LIMITATION OF WARRANTY The foregoing warranty shall not apply to defects resulting from improper or inade quate maintenance by Buyer Buyer supplied software or interfacing unauthorized modification or misuse operation outside of the environmental specifications for the product or improper site preparation or maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED HP SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE EXCLUSIVE REMEDIES THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES HP SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPE CIAL INCIDENTAL OR CONSEQUENTIAL DAMAG
354. oting the power meter readings at each frequency step The power meter readings should be within the limits specified 2 0 6 6 GHz 2 00 dB _____ _ 2 00 dB Tune the Signal Generator from 6 6 to 12 3 GHz in 1 GHz steps while noting the power meter readings at each frequency step The power meter readings should be within the limits specified 6 6 12 3 GHz 2 00 dB 2 00 dB Tune the Signal Generator from 12 3 to 16 0 GHz in 1 GHz steps while noting the power meter readings at each frequency step The power meter readings should be within the limits specified 12 3 16 0 GHz 2 50 dB _______ 2 50 dB Repeat steps 9 through 18 using the power levels and frequency ranges listed in Table 4 2 4 54 HP 8673C D PERFORMANCE TESTS ABSOLUTE LEVEL ACCURACY TESTS contd Procedure cont d 2 0 dBm 10 dB RANGE 5 0 dBm 0 dB RANGE 10 dBm 0 dB RANGE 10 dBm 10 dB RANGE 20 dBm 20 dB RANGE Output Power f Frequency Range 0 05 2 0 GHz 2 0 6 6 GHz 6 6 12 3 GHz 12 3 18 6 GHz HP 8673D only 18 6 26 0 GHz 0 05 2 0 GHz 2 0 6 6 GHz 6 6 12 3 GHz 12 3 18 6 GHz HP 8673D only 18 6 26 0 GHz 0 05 2 0 GHz 2 0 6 6 GHz 6 6 12 3 GHz 12 8 18 6 GHz HP 8673D only 18 6 26 0 GHz 0 05 2 0 GHz 2 06 6 GHz 6 6 12 3 GHz 12 3 18 6 GHz HP 8673D only 18 6 26 0 GHz 0 05 2 0 GHz 2 0 6 6
355. output pulse and amplitude modula tion apply only over the temperature range of 15 to 35 C 2 13 Bench Operation The instrument cabinet has plastic feet and fold away tilt stands for convenience in bench opera tion The plastic feet are shaped to ensure self aligning of the instruments when stacked The tilt stands raise the front of the instrument for easier viewing of the front panel 2 14 Rack Mounting WARNING The Signal Generator weighs 42 3 kg 94 lbs therefore extreme care must be exercised when lifting to avoid personal injury To avoid personal injury and equipment damage use equipment slides when rack mounting the instrument Rack mounting information is provided with the rack mounting kits If the kits were not ordered with the instrument as options they may be ordered through the nearest Hewlett Packard office Refer to the paragraph entitled Mechanical Options in Section I 2 15 STORAGE AND SHIPMENT 2 16 Environment The instrument should be stored in a clean dry environment The following environmental lim itations apply to both storage and shipment HP 8673C D Environment cont d Temperature e e eee eees 55 to 75 C Humidity Skid K x ah 9 A RR RN 0 lt 95 relative AIntude uaaa 15 300 metres 50 000 feet 2 17 Packaging Preparation for Packaging Remove handles and or rack mount flanges before packaging instrument for shipping Tagging for Service If the instr
356. owed to approximately 100 milliseconds Disabling Auto Peak will speed frequency switching time at the expense of degradation of risetime and overshoot Pulse specifications only apply when Auto Peak is enabled The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program will set the pulse mode to the mode specified by the variable Mode 10 SUB Pulse_mode Err Mode 20 30 SELECT UPCS TRIMS ModeS 40 CASE NORM NORMAL 50 Code P2 Code for NORMAL mode 60 CASE COMP COMPLEMENT 70 Code P3 Code for COMPLEMENT mode 80 CASE OFF 90 Code P0 100 CASE ELSE 110 Err 1 120 DISP Invalid pulse mode specified 130 END SELECT 140 150 OUTPUT 719 USING 2A Code 160 170 SUBEND The following message number may be displayed when pulse modulating For a more complete description of the message see the MESSAGES detailed operating instructions 90 An error occurred in the Auto Peak operation Service may be required to correct the problem HP 86738C D Description Local Procedure Remote Procedure Operation Detailed Operating Instructions Range Output Level The RF output level of the Signal Generator is set using the RANGE and VERNIER controls The RANGE controls change the RF output level in 10 dB steps and the VERNIER changes the RF output level continuously over a 13 dB range The sum of the output level RANGE and VER
357. ows easy stepping with a single key press In addition holding down the frequency incre ment step key will allow tuning at a rate of about ten steps per second This power o tune feature does not offer as much control as the TUNE knob because the stepping rate is fixed for the frequency increment step keys The nine store recall registers of the Signal Generator allow up to nine different front panel settings to be stored and recalled This feature is useful when several unrelated frequencies are required Each register can be stored with the same frequency increment or different frequency increments depending on the application A simple two stroke key sequence will recall each register as needed lt 7 To set the Signal Generator frequency increment 1 Press the FREQ INCR key to indicate that the next entry will be for frequency increment 2 Enter the desired frequency increment using the numeric keypad If a mistake is made while entering the frequency increment press the backspace key until the incorrect digit disappears Continue entering the correct digits until the frequency increment displayed in the FREQUENCY MHz display is correct 3 Press the appropriate units key You may enter the frequency increment in GHz MHz or kHz The entered frequency increment will be displayed as long as the units key is held down The frequency may now be incremented or decremented using the TUNE knob or the FREQ INCREMENT up
358. p Size HZ SP of Steps SS LF and EOI Output Couple Output Lock Frequency Test Interface Output Status Output Request Mask START Value Center Frequency Value Dwell Value LF and EOI 2 Bytes EOI 1 Byte EOI HP 8673C D See Section VIII Service Valid Functions CF FI FA FB FS M1 5 DW LE VE RA Frequency is in Hz dwell is in milliseconds OK FR Numeric Value Hz LF and EOI TI 1 Byte 1 Byte EOI OS Sending the Data Message contd Output Couple After receiving the program code OC Output Couple and when addressed to talk the Signal Generator sends a data string that gives the current numeric values for the following param eters in the order listed START Center Fre quency DWELL LF and EOI No program codes prefix the numeric values Hz is the implied terminator for start and center frequency milli seconds is the implied terminator for dwell time Output Lock Frequency This function causes the Signal Generator to output the value of its tuned frequency After receiving the program code OK and when addressed to talk the Signal Generator sends the value of the frequency at which it is currently phase locked The data output from the Signal Generator is in the following format FR Numeric Value HZ LF and EOI Test Interface Function This function allows test ing of the HP IB interface After receiving the program code TI followed by an 8 b
359. p frequency is controlled by the number of steps or the sweep step size parameters The Signal Generator has three sweep modes to accommodate a variety of applications Auto sweep mode is used when a repetitive sweep is required Auto sweep mode will step the RF output frequency from the start frequency to the stop frequency and then repeat the sweep until the sweep is turned off or a band crossing is encountered Single sweep mode will step the RF output frequency from the start frequency to the stop frequency once and then stop This mode is useful when a single sweep is required for a measuring device to store the results Additional control signals are provided for control of X Y recorders and external displays Manual sweep provides a convenient method to limit the tuning range of the frequency tuning controls In applications requiring a single band of frequencies the tuning limits can be set to cover the band of interest which allows the user to tune the frequency without having to watch the Signal Generator display to determine when the frequency is outside of the selected band There are four rear panel connectors that are used for sweep coordinating signals SWP OUT provides a signal that is 0 volts at the beginning of a sweep and 10 volts at the end of the sweep regardless of the sweep width The output impedance is nominally 100 kilohms The TONE MKR connector provides a5 kHz signal when an active marker frequency is generated This
360. panel AUX control connector requires a male 14 pin Micro Ribbon 57 Series connector The HP part number is 1251 0142 This connector is also available from Amphenol Oak Brook Illinois 60521 Intercon nection data for the rear panel AUX control con nector is provided in Figure 2 5 Coaxial Connectors Coaxial mating connectors used with the RF Output of the Signal Generator should be APC 3 5 female connectors CAUTION Using an SMA connector may damage the RF output connector unless care is used to avoid excessive torque 2 11 Frequency Reference Sensitivity Selection The Signal Generator generates a de voltage that is proportional to the CW RF frequency This volt 2 4 HP 86738C D age is available at the rear panel FREQ REF con nector Signal Generators with serial number pre fixes of 2626A 2608A and 2540A and below have a frequency reference voltage sensitivity of 1 V GHz Signal Generators with serial number prefixes of 2552A or 2634A and above havea select able frequency reference voltage sensitivity of 5 V GHz or 1 V GHz The sensitivity is selected using C1 of switch 52 on A2A7 the I O assembly 2 12 Operating environment The operating environment should be within the following limitations Temperature 2 66 s cece ec cece 0 to 55 C Humidity state ad owe ae args lt 95 relative Altitude lt 4570 metres 15 000 feet Specifications for harmonically related spurious signals RF
361. parallel poll sense using a parallel poll configure command The assigned data line is the line that the Signal Generator will output the SRQ if itis set The sense determines whether the active true value will bea logical zero or a logical one For example assigning the Signal Generator parallel poll response to data line five and the sense to false will cause the Signal Generator to output a false signal on data bus line five when the parallel poll occurs if the SRQ bit is set Program Function Clear status and extended status bytes Output Request Mask in binary Output status and extended status bytes in binary Prefix to set Request Mask in binary Prefix to set Request Mask in binary STATUS BYTE 4 8 2 WEIGHT 8 4 2 za Condition Change RQS Bit Entry End af Source Change Front Front in Sweep Request Error Sweep Settled in Ex Panel Panel Parame Service tended Entry Key ters Status Complete Pressed ee weet ee Condition lt S leveled i ure On Locked When using the status byte to monitor the results of program strings care must be taken to avoid incorrect results When the instrument is preset and the frequency and or level do not change the SOURCE SETTLED bit will be set before the extended status byte is set In addition some conditions may cause bits in the extended status byte to not be set For maximum assurance th
362. potential shock hazard of work ing on an instrument with protective covers removed Installation To avoid hazardous electrical shock the line mains power cables should be disconnected before attempting to change the internal HP IB address switch settings NOTE The HP IB address switches can be set with out removing any circuit boards from the Signal Generator If any circuit boards are removed observe all electrostatic discharge precautions to avoid damaging the Signal Generator a Set the LINE switches to STBY and OFF Disconnect the line power cables b Remove the Signal Generator s top cover by removing the two plastic standoffs from the rear of the top cover and loosening the screw at the middle of the rear edge of the top cover c Remove the A2 Assembly s protective cover The A2 Assembly is located just forward and to the left of the fan as viewed from the rear d Locate the A2A9 Frequency Output HP IB Assembly This assembly can be recognized as having one black and one white printed circuit board extractor e Set the switches to the desired HP IB address in binary or the Talk Only or Listen Only setting The switch is illustrated in Figure 2 3 If both the Talk Only and the Listen Only switches are set to 1 the Talk Only setting overrides the Listen Only setting Setting the address switch to Talk Only or Listen Only selects a unique HP IB address Talk Only 50 Listen Only 40 Talk O
363. ppropriate sensor The power meter must have an output signal that is proportional to the signal level in watts The recorder output of most power meters provides the feedback signal for power meter leveling External ALC using a power meter has the advantages of temperature compensation and wide dynamic range Using a sensitive power sensor allows ALC at levels as low as the power meter and sensor can measure The disadvantage of power meter leveling is the longer settling time and the added complexity of a separate instrument To set the Signal Generator for power meter leveling 1 Connect the power meter to the remote point using a directional coupler or a power splitter The power meter sensor must have enough dynamic range to measure the level at the coupled port of the directional coupler For example to level a signal of 7 to 0 dBm using a 10 dB coupler the power sensor must be capable of measuring 17 to 10 dBm in a single range 2 Press the Signal Generator ALC INT key to set automatic leveling control to inter nal Adjust the Signal Generator output level to place the power meter in the appro priate range to monitor the coupled port over the required range Press the range hold key to prevent a range change A power meter range change will rescale the feedback voltage and cause oscillations in the leveling circuitry 3 Reset the Signal Generator range to at least 10 dB above the range required for the desired RF output le
364. proximately 10 dBm The range selected for the Signal Generator would then be 10 since 0 dB attenuation would be required and the 10 dB range is one step above zero attenuation HP 8673C D Operation Detailed Operating Instructions Power Meter Automatic Level Control conva Error The following message may be displayed when programming the RF output level Messages 24 The programmed RF output VERNIER RANGE or both is outside the Signal Generator s range 3 115 Operation HP 8673C D Detailed Operating Instructions Description Locai Procedure Remote Procedure Example 3 116 Pulse Modulation The Signal Generator provides normal and complemented pulse modulation In normal pulse modulation a TTL high level gt 8 volts will turn on the carrier while a TTL low level lt 0 5 volts turns the carrier off Complement pulse modulation uses a TTL low level to turn on the carrier and a TTL high level to turn off the carrier Having two modes available allows easiest interfacing to positive or negative logic conventions Pulse widths more narrow than the specified minimum pulse width will light the ALC UNLEVELED annunciator to indicate that the pulse peak level accuracy is degraded Pulse overmodulation is indicated by the ALC UNLEVELED annunciator Pulse overmodulation occurs at narrow pulse widths as mentioned above and at very low duty cycles when the time between pulses exceeds the instrument s ability to retai
365. psor a 09 RHG DMS1 26 Procedure Sensitivity and Meter Accuracy 1 Connect the equipment as shown in Figure 4 37 NOTE Connect the mixer directly to the local oscillator to avoid any power loss 2 Set the Signal Generator as follows FREQUENCY ccc cece cece cee 2 GHz OUTPUT LEVEL RANGE 0 dB OUTPUT LEVEL VERNIER 5 dBm FM DEVIATION range 0 3 MHz Meter Scale vos ob oxen cinea date deez FM 4 86 HP 8678C D Performance Tests PERFORMANCE TESTS EXTERNAL FM ACCURACY AND METER ACCURACY cont d Procedure contd BNC TEE TEST OSCILLATOR HP 8673C D SYNTHESIZED SIGNAL GENERATOR LOCAL OSCILLATOR FM IN j RF OUTPUT OUTPUT MIXER RFK ALO P OY DIGITAL VOLTMETER MEASURING RECEIVER Figure 4 37 External FM Accuracy and Meter Accuracy Test Setup Tune the local oscillator to 2 5 GHz with an output amplitude of 8 dBm Set the measuring receiver to measure FM Set the test oscillator to a 100 kHz rate Adjust the output level to obtain a full scale reading on the Signal Generator s front panel meter The measuring receiver should read 300 kHz 45 kHz deviation Record the reading FM reading 255 kHz 945 kHz Adjust the test oscillator level to obtain 50 kHz deviation as read on the Signal Generator s front panel meter Themeasuring receiver should read 50 kHz 15 kHz deviation Record thereading FM reading 35 kHz 65 kHz Ac
366. quency 100 kHz to 400 kHz Gain 26 6 dB Output Power gt 7 dBm Noise Figure lt 8 5 dB Impedance 500 Recommended Model HP 1980B 19860A HP 436A HP 8485A HP 8447D Power Amp Frequency 100 kHz to 400 kHz Gain 22 5dB Output Power gt 6 dBm Noise Figure lt 5 dBm Impedance 500 Rate 10 Hz to 4 MHz Rise and Fall Times lt 5 ns Output Impedance 50N Output Level 0 to 3 5V Pulse Width 80 ns to 2 us Frequency Range 50 MHz to 7 GHz Frequency Span Division 1 kHz minimum Amplitude Range 0 to 70 dB Level 0 to 3V into 500 or 3000 Range 10 kHz to 10 MHz HP 8447E Note HP 8447F is a dual amplifier and will satisfy both requirements HP 8116A or HP 8013B HP 8566B HP 3335A or HP 8116A RHG Electronics Laboratory Inc 161 East Industry Court Deer Park NY 11729 Tel 516 242 1100 TWX 510 227 6083 1 21 1 22 HD 8673C D Installation SECTION I INSTALLATION 2 1 INTRODUCTION This section provides the information needed to instali the Signal Generator Included is informa tion pertinent to initial inspection power require ments line voltage selection power cables inter connection environment instrument mounting storage and shipment 2 2 INITIAL INSPECTION WARNING To avoid hazardous electrical shock do not perform electrical tests when there are signs of shipping damage to any portion of the outer enclosure covers panels meters Insp
367. quency specified by the variable Expected The desired value must be in MHz and should be between 1 kHz and the maximum frequency of the Signal Generator 10 SUB Sweep_delta_set Err Expected Expected frequency in MHz 20 OUTPUT 719 USING 2A MG Read message from 8673 30 ENTER 719 USING 2A Message to clear any old messages 40 OUTPUT 719 USING 4A 5D DDD 2A CSDF Expected MZ T Update status 50 OUTPUT 719 USING 2A MG Check for message from 8673 60 ENTER 719 USING 2A Message 70 SELECT VAL Message 80 CASE 1 Frequency was out of range 90 Err 4 100 DISP WARNING Attempt to set sweep delta frequency out of range 110 CASE 11 120 Err 11 130 DISP WARNING Sweep start frequency adjusted to be in range 140 CASE 12 Auto Peak Error 150 Err 12 160 DISP WARNING Sweep stop frequency adjusted to be in range 170 CASE ELSE 180 Err 0 Other errors not applicable 190 END SELECT 200 210 OUTPUT 719 USING 4A DFOA Requests current delta freq 220 ENTER 719 USING K Set_fregq Frequency in Hz 230 240 IF Set_freq lt gt Expected THEN 250 DISP WARNING Error in programmed delta frequency 260 END IF 270 SUBEND End of subroutine HP 8673C D Error Messages Operation Detailed Operating Instructions Delta Frequency Sweep conta The following message numbers may be displayed when setting the sweep delta frequency Hach mes
368. quency range Above 6 6 GHz the programmed frequency may be rounded by the Signal Generator to be compatible with the 2 3 or 4 kHz frequency resolution at the programmed frequency Specifying a marker in remote mode is done using the letter M followed by the marker number For example M1 specifies marker 1 Deactivating all markers is done by specifying marker zero M0 Deactivating a single marker is done by specifying a marker and then sending the program code MO Marker Off Activating a marker is done by specifying a marker For example the program string M5 will activate marker 5 To set the marker to a specific frequency the marker is specified and then the frequency is specified with the appropriate units terminator GZ MZ KZ or HZ The sweep marker frequency can be read for any given marker by specifying the marker followed by the output active program suffix The Signal Generator will send the frequency in fundamental Hz units Ifthe marker frequency is read as a string the format will be the program code MK followed by the marker frequency in Hz and then the units terminator Hz To set marker 3 to 12 34 GHz Local 1 Press the MKR key 2 Keyin3 using the numeric keypad This indicates that marker 3 is to be acted upon by the next entry and activates marker number three Note that the FREQUENCY MHz display shows the current sweep marker frequency when the 3 is pressed 3 Key in 12 34 using the numeric keypad The
369. r 1 FREQ INCREMENT Up Marker 2 VERNIER Marker 3 SWEEP MODE OFF Marker 4 SWEEP MODE OFF Marker 5 AUTO Sweep FREQ display off MANUAL Sweep FREQ display on SINGLE Sweep Start of Front Panel Learn Mode SINGLE Sweep Arm Only Prefix for Request Mask SINGLE Sweep Arm and Begin Deferred Execution Mode Master Sweep immediate Execution Mode Slave Sweep Start of Special Function Learn Mode 3 43 3 44 HP 8678C D Operation Detailed Operating Instructions Table 3 7 Index of Detailed Operating Instructions Note The Detailed Operating Instructions are referenced to the front panel controls and are arranged in alphabetical order Function Subjects AUTOMATIC Diode Automatic Level Control LEVEL CONTROL Internal Automatic Level Control Power Meter Automatic Level Control System Automatic Level Control FREQUENCY Frequency CW Frequency Increment and Tuning MISCELLANEOUS Auto Peak CAPABILITIES Master Slave Sweep Messages Multiplier Mode Normal and Bypass Modes Offset Frequency Recall and Store Registers Status Byte and Polling MODULATION Amplitude Modulation Frequency Modulation Pulse Modulation RF OUTPUT LEVEL Range Output Level RF Output On Off Vernier Output Level Auto Sweep Mode Center Frequency Sweep AFrequency Sweep Dwell Time Sweep Manual Sweep Mode Marker Frequency Sweep Single Sweep Mode Start Frequency Sweep Steps Sweep Step Size Sweep Stop Frequency Sweep
370. r even mixed upper and lower case The Signal Generator output frequency is valid once the SOURCE SETTLED bit of the status byte is set see Comments Program Code Applicable Function Preferred Program Code Due to the use of frequency multiplication to generate frequencies above 6 6 GHz the frequency sometimes cannot be set precisely to a desired value Frequencies below 6 6 GHz can be set to the nearest 1 kHz All frequencies between 6 6 and 12 3 GHz can be set within 2 kHz of the desired value Frequencies between 12 3 and 18 6 GHz can be set within 3 kHz of the desired value and frequencies between 18 6 and 26 5 GHz can be set within 4 kHz of the desired frequency However with careful selection of frequency the roundoff error can be reduced to 1 kHz below 18 6 GHz and 2 kHz for frequencies between 18 6 and 26 5 GHz When the Signal Generator is programmed to a frequency that cannot be set exactly due to frequency resolution a random roundoff occurs To prevent this the remote program should perform a calculation to determine whether the frequency can be set exactly and adjust the desired frequency accordingly To determine whether a frequency can be set to a given value divide the desired frequency in kHz by two ifitis between 6 6 and 12 3 GHz by three if itis between 12 3 and 18 6 GHz or by four if it is above 18 6 GHz If the result is a whole number no remainder the frequency can be set to the desired value For e
371. r less than 24 hours the aging rate is lt 5 x 10 day after a 24 hour warmup Switching time for frequency to be within specified resolution and output to be within 3 dB of set level CW and AM modes AUTO PEAK disabled is typically lt 20 ms for frequency changes that do not cross inter nal filter or amplifier switching points Filter switch ing points are 2 3 5 6 and 22 GHz The HP 8673D has an amplifier switching point at 16 GHz External Reference Input 5 or 10 MHz at a level of 0 1 to 1 Vrms into 500 Stability and spectral purity of the microwave output will be partially determined by characteristics of the external reference frequency Reference Outputs 10 MHz at a level of 0 2 Vrms into 500 SPECTRAL PURITY Residual FM in CW and FM Modes 0 05 to 6 6 GHz noise and power line related Past Detection Bandwidth 12 Hz rms 60 Hz rms Mode FM Range CW 30 100 300 kHz V and 1 3 MHz V 10 MHz V 15 Hz rms 75 Hz rms Residual FM doubles for 6 6 12 3 GHz triples for 12 3 18 6 GHz and quadruples for 18 6 26 0 GHz Spurious Signals CW and AM modes Option 003 instruments 400 Hz line operation Power line related and fan rotation related within 5 Hz below line frequency and multiples thereof Offset from Carrier Frequency b d 2 0 6 6 65 dBc gt 6 6 12 3 59 dBe gt 12 3 18 6 55 dBe gt 18 6 26 0 53 dBe Harmonies up to 26 GHz NORMAL meade 10 dBm vernier setting on 0 dBm ran
372. r meter leveling is the longer settling time 0 2 to 6 seconds 23 dB of dynamicrange is typically available using the Signal Generator s 0 and 10 dB ranges In addition amplitude modulation up to 90 depth at rates as high as 100 kHz is typically available using external power meter leveling mode since the Signal Generator s internal detector is used to provide the AM detection The response time for a level change using power meter leveling mode will vary depending on the type of power meter the power meter range setting and filter setting if used of the power meter Settling time increases as the sensitivity of the range used increases In addition the response to a level change can be underdamped critically damped or overdamped depending on the type of meter and filter selection Typical 99 settling times for the HP 436A and HP 438A power meters are shown in the following table The 99 settling time is the time the power meter requires to make a measurement in a given range HP 8678C D Operation Detailed Operating Instructions Power Meter Automatic Level Control conta Comments Power Meter Range Setiling Times cont d Power Typ 99 Settling Meier Range HP 436A The leveling system will have a longer settling time due to the settling time of the Signal Generator ALC circuitry and the response time of the signal path Typical settling times for leveling using the HP 482A B HP 435B HP 486A and HP 438A power
373. r meter reading The reading should be within the specified limits 12 13 14 15 Record the reading 18 6 GHz 0 dBm 2 25 dBm 2 25 dBm Adjust the Signal Generators RANGE to 10 dB Observe the power meter reading The reading should be within the limits specified Record the reading 18 6 GHz 10 dBm 12 85 dBm _ 7 15 dBm Adjust the RANGE to 20 dB Observe the power meter reading The reading should be within the limits specified Record the reading 18 6 GHz 20 dBm 23 05 dBm _________ 16 95 dBm Low Level Accuracy Test 16 17 18 Disconnect the power meter and connect the Signal Generator to the attenuator and mixer as shown in Figure 4 8 NOTE Connect the mixer directly to the local oscillator to avoid any power loss Tune the local oscillator to 18 7 GHz Set the output power to 7 dBm Set the resolution bandwidth on the spectrum analyzer to 300 Hz or less Adjust the vertical sensitivity to place the peak of the 100 kHz IF signal on the center hori zontal graticule line This calibrates the center graticule line for an absolute reference power level of 20 dBm 4 10 HP 8673C D Performance Tests ABBREVIATED PERFORMANCE TESTS LEVEL ACCURACY TESTS cont d Procedure Low Level Accuracy Test cont d cont d 19 Setthe RANGE of the Signal Generator 10 dB lower and adjust the VERNIER for a front panel meter reading of 0 dBm 20 Set t
374. r with 1 volt peak developing the maximum deviation for the selected range There are six FM peak deviation ranges available with maximum deviations of 0 03 0 1 0 3 1 3 and 10 MHz respectively FM peak deviation is monitored using the Signal Generator s front panel meter in the FM meter mode The meter monitors the signal at the FM IN connector and displays the corresponding FM peak deviation in MHz An overmodulation condition is indi cated by the FM OVERMOD annunciator when the modulation index exceeds 5 or the input signal exceeds 1 volt peak To set the Signal Generator to a desired FM peak deviation 1 Select an FM deviation range that is greater than the desired FM peak deviation 2 Connect an external oscillator to the FM input and set the frequency of the external oscillator to the desired modulation rate at an amplitude of 0 volts 3 Press the Signal Generator s FM meter mode key which is located near the front panel meter This will allow the amplitude of the external oscillator to be monitored as the desired FM peak deviation 4 Adjust the external oscillator amplitude until the meter indicates the desired FM peak deviation If the FM OVERMOD annunciator is lighted reduce the peak deviation or increase the modulating rate until the annunciator extinguishes The peak deviation divided by the modulating rate must be less than or equal to the maximum modulation index for the carrier frequency The FM range can be program
375. rameters that do not immediately change the output frequency However the bit is not always valid as an indica tion that the RF output is settled and should only be used to check for settling of the intended parameter changes END OF SWEEP During sweep mode the END OF SWEEP bitis used to indi cate that the current sweep has finished In AUTO sweep mode the bit will be set once each time the stop frequency is reached In MANUAL sweep mode the bit will be set anytime the start or stop frequency is reached The bitis set when the stop frequency is reached for SINGLE sweep mode The bit can be used to detect when a single sweep is finished so the controller can spend time com puting while the Signal Generator is sweeping ENTRY ERROR The ENTRY ERROR bit is set when an invalid front panel key sequence HP IB program code or parameter value is entered This bit corre sponds to the front panel MESSAGE key Reading the message after detecting this bit will enable the controller to identify and possibly correct the error RQS SERVICE REQUEST BIT The Signal Generator can generate a service request when one or more of the bits in the status byte are set A request mask must be set to allow one or more of the bits to generate a service request At power on the request mask is set to disable any of the bits from generating a service request A bit is enabled by setting the corresponding bit in the request mask to a logical one true The front pa
376. rations are also indicated by the setting of this bit the status byte should be cleared before performing the Auto Peak operation The Auto Peak can then be performed and will be finished when the bit is set Program Code Description Disables Auto Peak Operations Enables and Performs Auto Peak Operation Performs Auto Peak Operation Without Settling Preferred program code Auto Peak operations will produce small perturbations in the output level during peaking as the filter passband is adjusted If the tuning is too far off to be centered by the Auto Peak operation message 90 will be issued to indicate that the filter tracking requires adjustment When Auto Peak operations are disabled the filter fine tuning is not changed This feature can be used to achieve faster frequency switching time by performing a peak at the destination frequency and then disabling peaking The frequency switching time will then be minimized since an Auto Peak operation will not have to be performed Wide band sweeps can also use this feature to maintain power level at the higher frequencies by peaking at the higher frequency band and then disabling Auto Peak operations Output power typically decreases with increasing frequency The Auto Peak operation is slowed when any FM rangeis selected FM is not completely turned off when an Auto Peak occurs due to the relatively long turn off time required by the FM circuitry Instead the FM range is set to the
377. rator s HP IB inter face is described earlier in this section under Remote Operator s Checks These checks verify that the Signal Generator can respond to or send each of the applicable bus messages described in Table 3 3 3 24 HP IB Compatibility The Signal Generator has a three state TTL HP IB interface which can be used with any HP IB computing controller or computer for automatic system applications The Signal Generator is pro grammable via the HP Interface Bus Its pro gramming capability is described by the twelve HP IB messages listed in Table 3 3 The Signal Generator s compatibility with HP IB is further defined by the following list of interface functions SH1 AH1 T5 TEO L3 LEO SR1 RL1 PP1 DC1 DT 1 and CO A more detailed explanation of these compatibility codes can be found in IEEE Stand ard 488 1978 and theidentical ANSI Standard MC1 1 For more information about HP IB refer to the Hewlett Packard Electronic Instruments and Sys tems catalog and the booklet titled Improving Measurements in Engineering and Manufactur ing CHP part number 5952 0058 3 25 Remote Mode Remote Capability The Signal Generator com municates on the bus in both remote and local modes In remote most of the Signal Generator s front panel controls are disabled Exceptions are the LINE switch the LOCAL key the MTR keys the MESSAGE key and the FREQUENCY FREQ INCR SWEEP FREQ and SWEEP RATE keys for displayin
378. re contd Example Program des ED 3 108 Offset Frequency conra Once the offset frequency is programmed the controller can read the entered value using the output active program code suffix To read the offset frequency send the program string FTOA and then read the actual frequency offset Ifthe offset frequency is read as a string the format will be the program code FT followed by the frequency offset positive or negative in Hz and then the units terminator Hz To set a frequency offset of 63 238 MHz Local 1 Press the blue shift key to indicate that a shifted function is to be accessed The shifted functions are printed in blue above certain keys 2 Press the OFFSET key if the displayed frequency is to be above the actual RF output frequency Press the OFFSET key if the displayed frequency is to be below the actual RF output frequency 3 Key in 63 238 using the numeric keypad The FREQUENCY MHz display should show 63 238 and should be left justified 4 Press the MHz units key to finish the sequence The FREQUENCY MHz display should show the entered frequency until the units key is released The FREQUENCY MHz display should be right justified when the units key is pressed The frequency could also have been entered as 063238 GHz or 63238 kHz The only difference is the placement of the decimal point and the units terminator Entering a frequency offset of zero will deactivate the frequency offset mode
379. re initialized and pending Service Re quests may get lost 3 44 Sending the Status Bit Message The Signal Generator sends the Status Bit mes sage if configured as part of the interface s response byte to the Parallel Poll Enable PPE bus command In order for the Signal Generator to respond to a Parallel Poll Enable bus command it must be assigned a single HP IB data line by the controller The controller also assigns the logic level of the bit Both tasks can be accomplished by the Parallel Poll Configure PPC bus command if the Signal Generator is sending the Require Ser vice message it will set its assigned status bit true The Signal Generator can send the Status Bit message without being addressed to talk The data line that the Signal Generator is assigned to respond on can be cleared by turning the instrument to STBY or by sending the Parallel Poll Unconfigure PPU bus command 3 45 Receiving the Abort Message The Abort message is the means by which the controller sets the Interface Clear IFC bus con trol line true When the Abort message is received the Signal Generator becomes unaddressed and stops talking or listening 3 41 Operation Program HP 8673C D Table 3 6 HP IB Program Codes 11 of 2 Parameter Level RANGE and VERNIER AM OFF AM OFF AM 30 AM 100 NORMAL Backspace BYPASS NORMAL BYPASS Center Frequency Clear Status Configure Trigger CW Frequency
380. red frequency If sweep mode is off the displayed frequency will indicate the frequency halfway between the start frequency and the new stop frequency If auto sweep is on the sweep will be reset and then continue using the new stop frequency If single sweep is on the sweep will be reset and the sweep will remain armed at the start frequency If manual sweep is on the sweep frequency will be reset to the start frequency To check the current sweep stop frequency press and hold the SWEEP FREQ STOP key The FREQUENCY MHz display will display the sweep stop frequency as long as the key is held When any sweep mode is turned off the CW frequency will be set to halfway between the start and stop frequencies equal to the sweep center frequency The Signal Generator accepts any sweep stop frequency within its specified frequency range Above 6 6 GHz the programmed frequency may be rounded by the Signal Generator to be compatible with the 2 3 or 4 kHz resolution at the programmed frequency see comments l HP 8673C D Remote Procedure cont d Example Operation Detailed Operating Instructions Stop Frequency Sweep conta The format of the remote programming follows the front panel key sequence To program the sweep stop frequency the program code FB is sent followed by the desired frequency and the units GZ MZ KZ or HZ If setting the new start frequency causes a change of the CW frequency normally the case the SOURCE
381. requires a certain length of time to process a command For example when setting frequency the Signal Gen erator can require anywhere from several milliseconds to 50 milliseconds to change frequency and settle the RF output level The actual time required depends on the frequency change see CW Frequency If the application waits 50 milliseconds the specified worst case frequency switching time after 3 137 Operation HP 8673C D Detailed Operating Instructions Description cont d 3 138 BIT5 BIT 6 BIT7 BIT 8 Status Byte and Polling conra each frequency change the RF output will be settled Note that the wait must start after the Signal Generator has received the frequency programming string For controllers with buffered output capability an additional wait is required to allow the buffered output to be received by the Signal Generator However for applications requiring faster execution the source settled bit can be monitored to determine when the RF output has settled Since most fre quency changes will be much faster than the worst case frequency switching time the application will execute faster if the SOURCE SETTLED bit is monitored The SOURCE SETTLED bit is intended to indicate settling after the RF output or AUTO PEAK is turned on and when FM ranges frequency output level or pulse modes are changed The bit will be set after any parameter change except AM storing a register and changing sweep pa
382. ries The Operating Manual which is shipped with each instrument has four sections Section I General Information Section II Installation Section II Operation Section IV Performance Tests The Service Manual which is shipped with the instrument as Option 915 or ordered separately has four sections Section V Adjustments Section Vi Replaceable Parts Section VII Manual Changes Section VIII Service Additional copies of the Operating Manual or the Service Manual can be ordered separately through your nearest Hewlett Packard office 1 2 SPECIFICATIONS Instrument specifications are listed in Table 1 1 These specifications are the performance stand ards or limits against which the instrument may be tested Supplemental characteristics are listed in Table 1 2 Supplemental characteristics are not warranted specifications but are typical charac teristics included as additional information for the user 1 3 SAFETY CONSIDERATIONS This product is a Safety Class I instrument that is one provided with a protective earth terminal The Signal Generator and all related documenta tion should be reviewed for familiarization with safety markings and instructions before opera tion Refer to the Safety Considerations page found at the beginning of this manual for a sum mary of the safety information Safety informa tion for installation operation performance test ing adjustment or service is foundin appropriat
383. riggered to view the level switching process Set the oscilloscope as follows Channel 1 Vertical Sensitivity to 5 mV Division Coupling to DC Set sweep to delayed Main Sweep Parameters External trigger with DC coupling Positive slope trigger Auto sweep mode Delayed Sweep Parameters Internal trigger with AC coupling Positive slope trigger Auto sweep mode NOTE Triggered sweep mode must be used to trigger the digitizer at the start of the simultaneous level and frequency change If auto sweep mode is selected on the oscilloscope while digitizing the oscilloscope will trigger the sweep even without an external trigger signal and the waveform digitized will not be valid for this measurement Set the oscilloscope s main sweep to 5 ms per division and delayed sweep to 1 ms per division The delayed sweep will be used once the approximate delay required is determined from the main sweep Set the Signal Generator to the following conditions Output Level i ose bls oda duty See ad hes 0dBm H Ce ee Internal Modulation asia cones otaeacdta cheb Off Sweep Mode cc ccc cceeenceeees Manual Start Frequency ccs4iasadss oe Rewse keen 3 000 000 MHz Stop Frequency cceee cee cceees 3 000 010 MHz 1 Nee A Ones d Mama enue eae nis 10 Steps WE i oi ne oe BAM nln Oe care ee ete wna 20 ms Set the oscilloscope to main sweep with auto sweep mode to view the signal without using the external trigger signal Enter and run the follo
384. rmance Tests HP 8678C D ABBREVIATED PERFORMANCE TESTS 4 7 ABBREVIATED PERFORMANCE TESTS TURN ON CHECKS Procedure 1 Set the upper and lower LINE switches to ON 2 Ensure that the message key indicator is not flashing If the message key indicator is flashing refer to the pull out card for a list of message codes 3 Press RCL O Verify that the instrument is now preset to the following conditions RF OUTPUT to ON ALC to INTERNAL OUTPUT LEVEL RANGE to 70 dB 0 dB for Option 001 or 005 AUTO PEAK to ON MTR scale to LVL AM FM and PULSE Modulation to OFF FREQUENCY to 3000 000 MHz FREQ INCR to 1 000 MHz START to 2000 000 MHz STOP to 4000 000 MHz AF to 2000 000 MHz SWEEP mode to OFF STEP to 100 Steps 20 000 MHz DWELL to 20 ms TUNE Knob to ON All Status Annunciators off MESSAGE key indicator off NORMAL BYPASS to NORMAL 4 2 HP amp 8673C D Performance Tests ABBREVIATED PERFORMANCE TESTS FREQUENCY RANGE AND RESOLUTION TEST Description This test checks the tuning resolution and phase lock capabilities of the baseband 2 0 to 6 6 GHz frequency generation circuitry using a frequency counter Equipment Frequency Comter HP 53483A HP 8673C D SYNTHESIZED FREQUENCY SIGNAL GENERATOR COUNTER a gt FREQUENCY FREQUENCY STANDARD IN STANDARD OUT 2 RF OUTPUT Figure 4 1 Frequency Range and Resolution Test Setup Procedure 1 Connect the equipment as shown in Figure 4 1 Set the Signal G
385. rmonic and then entering a frequency offset equal to the desired offset enables the local oscillator to be set to the frequency of the signal to be downconverted The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The following program is used to set the frequency offset to the offset specified by the variable called Expected The offset can be positive or negative and must be in units of MHz 10 SUB Offset_treq Err Expected 20 30 OUTPUT 719 USING 2A MG Clear any old messages 40 ENTER 719 USING 2A Message 50 60 OUTPUT 719 USING 24 5D DDD 2A FT Expected MZ 70 80 OUTPUT 719 USING 2A MG Check for errors 90 ENTER 719 USING 2A Message 100 SELECT VAL Message 110 CASE 1 120 Err 1 130 DISP ERROR Offset frequency is out of range 140 CASE ELSE 150 Err 0 160 END SELECT 170 180 OUTPUT 719 USING 4A FTOA Read offset back 190 ENTER 719 USING K Offset 200 210 IF ABS Offset 1 E 6 Expected gt 001 THEN t More than 1 kHz error 220 Err 1 230 DISP WARNING Programmed offset is more than 1 kHz in error 240 END IF 250 260 SUBEND The following message may be displayed when setting the offset frequency The message is explained as it pertains to setting offset frequency For a more complete description of the messages see the MESSAGES detailed operating instructions 01 The entered frequency is not
386. rogram can be called to wait for a source settled indication from the Signal Generator The program will wait a maximum of 1 second before assum ing the SOURCE SETTLED bit is not going to be set The status byte must be cleared with the CS program code before the frequency is set If the status byte is not cleared the SOURCE SETTLED bit may have been set by a previous command the bit is latched until the status byte is read or cleared 500 SUB Settled 510 T_counter TIMEDATE i In case no source settled 520 Stat SPOLL 719 f Serial poll 530 IF TIMEDATE T_counter gt 1 THEN Done Default of 1 second 540 IF NOT BIT Stat 3 THEN GOTO 520 Wait for set bit 550 Done 560 SUBEND Source is settled or 1 second has passed The following message numbers may be displayed when setting the sweep start frequency Each message is explained as it pertains to setting sweep start frequency For a more complete description of the messages see the MESSAGES detailed operating instructions O01 Entered frequency is not within the range of the Signal Generator 03 Invalid multiplier entry for system compatible instruments Error 03 is defined as BYPASS mode not functional below 2 GHz for non system compatible instru ments See paragraph 3 2 System Compatibility for more information about system compatibility Operation HP 86738C D Detailed Operating Instructions Error 06 Messages cont d 10 11 12 13 90 Stop Frequency Swe
387. rt and stop frequency will begin the sweep at the start frequency and end the sweep at the stop frequency Setting the center frequency and delta frequency will start the sweep at one half the sweep delta frequency below the center frequency and end the sweep at one half the sweep delta frequency above the center frequency Setting the CW frequency when sweep modes are off will also reset the sweep center frequency to the same value Setting the sweep center frequency will automatically reset the sweep start and stop frequencies to the required values The sweep step size will also be recalculated by dividing the sweep delta frequency by the current number of steps Resetting the start or stop frequency will reset the sweep delta frequency and will reset the sweep center frequency if a sweep mode is enabled or the CW frequency if sweep is off Changing the sweep center frequency has the effect of changing the start and stop frequencies by the same value The sweep center frequency can be set to any valid frequency within the Signal Generator s frequency range To set the Signal Generator to a specific sweep center frequency 1 Press the FREQUENCY key to indicate that the next entry will be for sweep center frequency This procedure is identical to the setting of CW frequency The Signal Generator always sets the CW frequency equal to the entered sweep center fre quency when sweep mode is turned off When sweep modes are on CW frequency entrie
388. rum analyzer is in gain compression If this happens increase the spectrum analyzer s input attenuation until a 3 dB increase in the Signal Generator s output level produces a3 dB change in the displayed signal level 5 Set PULSE MODE on the Signal Generator to NORM 6 Reduce the spectrum analyzer reference level as needed to observe the residual signal It should be gt 50 dB below the reference established in step 4 Record the reading 100 MHz BUD dB 7 Repeat steps 4 through 6 for the Signal Generator frequencies listed below Record the results in the table below Frequency Level GHz dB below reference i 4 65 Performance Tests HP 86738C D PERFORMANCE TESTS 4 19 PULSE RISE FALL TIME AND OVERSHOOT TEST Specification Description Equipment Procedure 4 66 Electrical Performance E Characteristics Characteristics Conditions PULSE MODULATION Rise and Fall Times AUTO PEAK enabled 0 05 to 0 1 GHz 0 1 to lt 2 0 GHz 2 0 to 26 0 GHz 0 05 to 0 1 GHz 0 1 to 6 6 GHz 7 2 to 26 0 GHz 6 6 to 7 2 GHz Overshoot Ringing The pulse test is divided into two parts pulse parameters below a Signal Generator frequency of 1 GHz and pulse parameters above a Signal Generator frequency of 1 GHz For frequencies below 1 GHz a low frequency mixer is used to generate an IF signal of 15 MHz For frequencies above 1 GHz a high frequency mixer is used to generate an IF signal o
389. s addressed to listen until it receives an Abort message or until its talk address or a uni versal unlisten command is sent by the controller Data Message Input Format The Data message string or program string consists of a series of ASCII codes Each code is typically equivalent to a front panel keystroke in local mode and follows one of three formats e Program Code Numeric Value Units Ter minator EOS Program Code Numeric Value EOS Program Code EOS 3 35 Operation k HP IB Receiving Data Messages contd Program codes are typically 2 character mnemon ics All codes normally used by the operator to control the Signal Generator are given in Table 3 6 HP IB Program Codes Numeric values are either a single decimal digit a set of 11 characters or less representing a number or a string of binary bytes A string of 11 charac ters maximum can be expressed in decimal form only Digits beyond the front panel display capa bility of a particular parameter are truncated Therefore it is best to format the data so that it is rounded to the correct number of digits Units terminators are 2 character codes that ter minate and scale the associated numeric value Frequency can be entered in GHz MHz kHz or Hz Sweep time values are entered in milliseconds Power values are entered in dB End of String messages EOS can be the ASCII characters Line Feed LF semicolon or the bus END m
390. s also reset the sweep center frequency to the same value 2 Enter the desired frequency using the numeric keypad If a mistake is made while entering the frequency press the backspace key until the incorrect digit disappears Continue entering the correct digits until the frequency displayed in the FREQUENCY MHz display is correct 3 Press the appropriate units key You may enter the frequency in GHz MHz or kHz Once the units key is pressed the displayed frequency will be adjusted to display MHz and the output frequency will be set Ifa sweep mode is active when sweep center frequency is entered the actual frequency displayed after pressing the units key will usually not be the entered frequency The FREQUENCY MHz display is used to display sweep information during sweep mode so the new sweep center frequency will not be displayed Setting the sweep center frequency during a sweep changes the center frequency to the value entered If auto sweep is enabled the sweep will continue about the new center frequency If manual sweep is enabled the sweep frequency will be reset to the new start frequency For sin gle sweep the frequency will reset to the new start frequency and the sweep will remain armed The center frequency can be tuned in the same manner as CW frequency except when manual sweep mode is active To check the current sweep center frequency during sweep press and hold the FREQUENCY key The FREQUENCY MHz display will display th
391. s anan H at ja tE 9 a G 9 en H goc 9g Cc L T oo PULSE IN RF OUTPUT PULSE GENERATOR OSCILLOSCOPE 20 dB MIXER ER a ss ATTENUATOR TRIGGER PULSE TRIGGER IF MIXER OUT EN CABLE VERTICAL INPUT 3 dB PREAMPLIFIER 10 dB POWER AMP ATTENUATOR ATTENUATOR Figure 4 27 Pulse Rise Fall Time and Overshoot Test Setup 4 Set the pulse generator and oscilloscope controls as follows Pulse Generator POSE Rate ws5d3s oat seer aoea k 1 MHz Pulse Width itso occa ter ae as 120 ns Pulse Amplitude 5V peak Oscilloscope Vertical Display Channel 1 DC 500 Coupling James Div Main 353504 3585s oiass 0 2 us Time Div Delayed 20 ns Vertical Sensitivity 0055 20 mV div Trigger Sieh cares fo TT aA TE wae External DC Coupled WOOD cde HR Zae R tee cers ee ree Triggered 5 Set the local oscillator address to 718 Enter and run the following program NOTE The following program will cause the local oscillator to track the frequency of the Signal Generator with a positive offset When the Signal Generator s output frequency is less than 1 GHz the offset will be 15 MHz When the Signal Generator s output frequency is 1 GHz or more the offset will be 70 MHz A change in the Signal Generator s frequency will be detected by the controller and the frequency output of the local oscillator will be automatically changed to maintain a positive offset 4 67
392. s below 6 6 GHz can be tuned with aminimum step size of 1 kHz For frequencies between 6 6 and 12 3 GHz the minimum tuning resolution is 2 kHz Frequencies between 12 3 and 18 6 GHz can be tuned witha minimum resolution of 3 kHz and frequencies between 18 6 and 26 5 GHz can be tuned with a minimum resolution of 4 kHz When setting a frequency increment the entered value can be as low as 1 kHz even though a 1 kHz tuning resolution is not possible for all output frequencies If a frequency increment is entered that is not a multiple of the specified frequency resolution for the RF output frequency the two nearest tuning resolutions will be used in combination so that the overall affect will be the desired tuning resolution For example if a frequency increment of 7 kHz is selected and the output frequency is set to 20 GHz tuning down one step will change the output frequency by 4 kHz for one step and then 8 kHz for the next three steps The overall affect is to change 28 kHz in four steps which is the same as four 7 kHz steps If the output frequency is reset to 5 GHz the tuning increment will be 7 kHz a multiple of the specified 1 kHz When tuning the frequency the time it takes to switch from one frequency to the next depends on the largest baseband lt 6 6 GHz frequency digit being changed Generally the smaller the digit being changed the shorter the switching time For example a change of 3 kHz the 1 kHz digit would be faster than
393. s made since 2 kHz steps would yield a span of 800 kHz while 3 kHz steps would provide a span of 1 2 MHz Since both of the resulting spans are incorrect the number of steps is increased to 500 to produce a 1 MHz span with 2 kHz steps The orig inal entry will be retained for recalculation when other sweep parameters are changed The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program is used to set the number of sweep steps to the number specified by the variable called Expected The desired value must be between 1 and 9999 steps 10 SUB Sweep_steps Err Expected 20 OUTPUT 719 USING 2A MG Clear message from 8673 30 ENTER 719 USING 2A Message to clear any old messages 40 OUTPUT 719 USING 2A DDDD 2A SP Expected SS Set size 50 OUTPUT 719 USING 2A MG Get any error message 60 ENTER 719 USING 2A Message 70 SELECT VAL Message 80 CASE 7 90 Err 1 100 DISP WARNING The number of steps is out of range 110 CASE ELSE 120 Err 0 130 END SELECT 140 150 SUBEND The following message numbers may be displayed when setting the number of steps Each message is explained as it pertains to setting the number of steps For a more com plete description of the messages see the MESSAGES detailed operating instructions 07 The entered number of steps is less than 1 or greater than 9999 13 The number of steps was adjusted to achieve a step size
394. sabled modulation performance and maximum output power may be degraded The time required for the Auto Peak operation is not included in the dwell time setting The automatic level control ALC bandwidth is increased when sweep mode is acti vated This provides fast response to switching transients when sweeping In addition activating sweep mode while amplitude modulating increases the useable AM band width by more than 250 times See the amplitude modulation detailed operating instruc tions for more information about AM bandwidth while in sweep mode The front panel annunciators are filtered in sweep mode to prevent false indications While sweeping the frequency changes cause a loss of phase lock and unleveled auto matic level control during the frequency change To prevent constant flashing of the front panel annunciators the response is damped to indicate only major problems during a sweep The bits of the extended status byte are also buffered and should not be used to check individual sweep points for phase lock and leveled RF output The following program is written in BASIC for HP 9000 Series 200 or 300 controllers The program is used to set the Signal Generator to the sweep mode specified by the variable Modez 10 SUB Sweep_set Err Mode 20 OUTPUT 719 USING 2A MG Read message from 8673 30 ENTER 719 USING 2A Message t to clear any old messages 40 SELECT Mode 50 CASE AUTO AUTOMATIC 60 Code
395. sage is explained as it pertains to setting sweep delta frequency For a more complete description of the messages see the MESSAGES detailed operat ing instructions 01 Entered delta frequency is not within the capability of the Signal Generator 11 Indicates that the desired sweep start frequency is below the frequency range of the instrument The start frequency is set to the lowest valid frequency 12 Indicates that the desired sweep stop frequency is above the frequency range of the instrument The stop frequency is set to the highest valid frequency 13 Number of steps were adjusted to give even step size This ensures that the full sweep span is covered by adjusting the number of steps For example if the number of steps is set to 100 and the delta frequency is set to 10 kHz the number of steps will be reset to 10 to accommodate the minimum frequency resolution of 1 kHz 3 63 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure 3 64 Diode Automatic Level Control Automatic Leveling Control ALC is used to maintain a constant power control ata given point External ALC enables the Signal Generator to level the signal level at a point other than the output of the Signal Generator The signal level must be detected using an external detector that provides a DC signal thatis proportional to the power at the remote point The Signal Generator will adjust the signal level at the RF output conn
396. scilloscope should be used to store and view the frequency switching process The test may be performed without a digit izing oscilloscope by repetitively switching the frequency of the unit under test but care should be taken to ensure that the number of frequency changes needed for the measurement are minimized Local Oscillator HP 8340A NIK OP ec cl cceys Valine cuore Aen RHG DMS1 26 Digitizing Oscilloscope HP 1980B 19860A 1 Set up the equipment as shown in Figure 4 12 The external trigger input of the oscilloscope is connected to the Signal Generator s rear panel Blanking Marker output This signal will trigger the oscilloscope at the start of a frequency change when any sweep mode is selected 4 28 HP 86738C D Performance Tests PERFORMANCE TESTS FREQUENCY SWITCHING TIME TEST cont d Procedure 2 Set the oscilloscope as follows cont d HP 8673C B SYNTHESIZED SIGNAL GENERATO BLANKING LT LOCAL OSCILLATOR MARKER OSCILLOSCOPE EXT TRIGGER CHANNEL 1 Figure 4 12 Frequency Switching Time Test Setup Channel 1 Vertical Sensitivity to 50 mV Division Coupling to AC Set sweep to delayed Main Sweep Parameters External trigger with DC coupling Positive slope trigger Auto sweep mode Delayed Sweep Parameters Internal trigger with AC coupling Positive slope trigger Auto sweep mode NOTE Triggered main sweep must be used to trigger the digitizer at the start of frequency change
397. se of the correct value in the holder Close the cover door WARNING To avoid the possibility of hazardous electri cal shock do not operate this instrument at line voltages greater than 126 5 Vac with line frequencies greater than 66 Hz leakage cur rents at these line settings may exceed 3 5 mA Figure 2 1 Line Voltage and Fuse Selection 220 240V OPERATION 100 120V OPERATION PLUG NEMA 6 15P CABLE HP 8120 0698 220 240V PLUG NEMA 5 15P 220 240V OPERATION OPERATION PLUG BS 1363A CABLE HP 8120 1351 The number shown for the plug is the industry identifier for the plug only The number shown for the cable is an HP part number for a complete cable including the plug Figure 2 2 Power Cable and Mains Plug Part Numbers 2 2 HP 86738C D 2 8 HP IB Address Selection In the Signal Generator the HP IB talk and listen addresses can be selected by an internal switch or by a front panel setting Refer to Table 2 1 for a listing of talk and listen addresses The address is factory set for a Talk address of S and a Listen address of 3 In binary this is 10011 in decimal this is 19 Table 2 1 AHowable HP IB Address Codes Decimal Equiv alent internal Switch Setting To change the internal HP IB address switch proceed as follows WARNINGS Internal switch settings should be changed only by service trained persons who are aware of the
398. set the Signal Generator to AM mode Press the AM key near the Signal Generator s front panel meter to set the meter to AM mode HP 86738C D Example cont d Program Codes Comments Programming Example Operation Detailed Operating Instructions Amplitude Modulation conrg 2 Set the external oscillator to the desired modulating rate and adjust the amplitude to zero volts 3 Connect the external oscillator to the Signal Generator s AM input connector Adjust the external oscillator amplitude until the middle scale 0 to 1 indicates 75 AM depth The required external oscillator amplitude will be approximately 0 75 volts peak or 0 53 volts rms Remote The programming string for setting the 100 AM depth rangeis A3 The amplitude and frequency of the modulating signal must be set by programming the external modulat ing signal source The alpha character A can be sent as upper or lower case i Program Cade Description AM Off AM Off AM 30 Range AM 100 Range AM bandwidth is determined by the frequency response of the automatic level control ALC circuitry Using internal leveling will provide the specified AM bandwidth up to the maximum specified AM depth External leveling will typically preserve the AM bandwidth but is dependent on the detector used System leveling on system compatible Signal Generators will typically reduce the usable AM bandwidth to 80 kHz Useable AM bandwidth can be
399. side the reference points noted in step 16 NOTE With the oscilloscope in delayed sweep mode the left graticule of the display corresponds to the delay time This delay must be added to the time from the left graticule to the last point the IF amplitude is outside of the references to obtain the amplitude recovery time lt 50 ms 4 33 Performance Tests HP 8678C D PERFORMANCE TESTS FREQUENCY SWITCHING TIME TEST cont d Procedure cont d 29 Repeat steps 12 through 20 for each of the start and stop frequencies listed in the following table Record the amplitude recovery time for each indicated frequency change gt SLT TTT b 3 dB R R RRR TULL 9999189981 1O CCC TTT T TTT ATA TATA Figure 4 16 Amplitude Recovery Measurement Waveform Start Frequency MHz 2000 000 6 601 000 3 000 000 4 000 000 HP 8673D only 12 301 000 18 601 000 2 000 000 6 601 000 2 000 000 Stop Frequeny MHz 6 600 000 12 300 000 4 000 000 10 000 000 18 600 000 26 000 000 26 000 000 26 000 000 18 600 000 LO _ Measured Frequency MHz 6 599 999 12 299 998 3 999 999 9 999 998 18 599 997 25 999 996 25 999 996 25 999 996 18 599 997 Recovery Time HD 8673C D Performance Tests PERFORMANCE TESTS 4 11 SINGLE SIDEBAND PHASE NOISE TEST Specification P Electrical Performance Characteristics Characteristics SPECTRAL PURITY Single sideband Phase Nois
400. strument placed the sweep start frequency below the frequency range of the Signal Generator 12 Indicates that the current sweep stop frequency is above the frequency range of the Signal Generator This error may be displayed when the SWEEP FREQ START key is pressed if tuning the instrument placed the sweep stop frequency above the frequency range of the Signal Generator 13 Number of steps were adjusted to give an even step size This ensure that the full sweep span is covered by adjusting the number of steps For example if the number of steps is set to 100 and the stop frequency is 2000 010 MHz setting the start frequency to 2 GHz will automatically adjust the number of steps to 10 to accom modate the minimum frequency resolution of 1 kHz 90 Auto Peak malfunction This indicates that the instrument may require service 3 99 Operation HP 8673C D Detailed Operating Instructions Description Local Procedure Remote Procedure Program Codes 3 100 Messages MESSAGE is a two digit code that indicates errors The error code indicates either a data entry error or a hardware malfunction When the error is an entry error the MESSAGE indicator on the front panel lights When the error is a hardware malfunction the MESSAGE indicator flashes To read the error code press the MESSAGE key on the front panel The two digit code will appear in the FREQUENCY MHz display when this key is pressed After reading the code cons
401. t from the signal generator is automatically leveled DIODE RF output power is leveled externally using a diode detector connected to the instru ment s EXT ALC IN connector PWR MTR Power Meter RF output power is leveled externally using a power meter connected to the instrument EXT ALC IN connector SYS System RF output power is leveled exter nally using a feedback voltage proportional to the system output power in volts per dB A system is the Signal Generator with an external amplifier multiplier etc The reference voltage must be 0 Vdc at 0 dBm system output and change 30 mV per dB This voltage is connected to the Signal Gener ator s EXT ALC IN connector CAL Adjustments Power leveled at the load is adjusted to agree with the OUTPUT LEVEL meter reading when external leveling is used in DIODE 3 5 Operation ALC Automatic Level Control cont d or PWR MTR External leveling techniques are discussed in Hewlett Packard Application Note 281 5 Microwave Synthesizer Series May 1981 HP Part Number 5952 8251 Application Note 218 5 specifically applies to the HP 8672A how ever the main principles of applications also apply to the HP 8673C D Additionally the input voltage fed back to the HP 8673C D EXT ALC IN connector should be within a 1V to 1V range Polarity is of no consequence because an internal circuit in the HP 8673C D performs an absolute value function on the input voltage 3 15 PULSE Mod
402. t level flatness This is especially important when using external amplifiers and mixers within the signal path The actual magnitude of the error introduced is dependent on the method used to generate the system feedback signal Example 1 An RF signal is required to deliver a 20 to 13 dBm signal in the range of 2to 20 GHz A system compatible amplifier is available that has a frequency range of 2 to 20 GHz and a maximum output level of 25 dBm The amplifier is connected to the Signal Generator and the system feedback signal from the amplifier is connected to the external ALC input connector on the Signal Generator front panel Pressing the shift key and then the SYSTEM key shifted DIODE sets the Signal Generator to system leveling mode The required output levels can be set directly using the RANGE and VERNIER controls Example 2 An amplifier and a frequency multiplier are to be connected together to form a frequency multiplier system The multiplier is system compatible and requires 17 dBm at the input The RF amplifier is capable of 20 dBm over the 2 to 20 GHz frequency range The system is connected by connecting the amplifier to the Signal Generator and the multiplier to the amplifier The system feedback signal is connected to the external ALC input connector on the Signal Generator front panel System leveling is set by pressing the shift key and then the SYSTEM key shifted DIODE The multiplied frequency can now be set using the R
403. t of the Signal Generator No calibration is required on the Signal Generator 5 Ifthe ALC UNLEVELED annunciator is on step the range up or down until the ALC UNLEVELED annunciator is extinguished The ALC UNLEVELED annun ciator indicates that the Signal Generator is unable to supply enough power because the signal path has too much attenuation or that the ALC circuitry cannot attenuate the Signal Generator s RF level enough to achieve leveling HP 8673C D Local Procedure contd Remote Procedure Comments Operation Detailed Operating Instructions System Automatic Level Control conta 6 When the Signal Generator is in the 0 10 and 20 dB ranges the system RF out put level is equal to the sum of the RANGE and VERNIER settings Range settings below 0 dB add attenuation to the signal path and do not affect the system level until the ALC goes unleveled The equipment setup for remote control of system leveling is the same as the local procedure The program code for system ALC is C4 The system level can be remotely controlled directly for power levels between 0 and 23 dBm For levels between 0 and 10 dBm the RANGE should be set to 0 dB and the VERNIER programmed for the appropriate level Using a range less than 0 dB while using external system leveling will have no effect on the level but can force the Signal Generator to lose control of the level due to insufficient attenuation lack of ALC dynamic range or too much
404. t were set after the status byte was stored The service request SRQ HP IB bus line is set true whenever the RQS bit of the status byteis set The front panel SRQ annunciator is also lighted when the RQS bitis set The service request is cleared when a clear status CS is executed or the extended status byte is read OS When the controller detects a service request by testing the HP IB SRQ line a serial poll must be performed for each instrument on the bus to determine which instrument generated the request For large systems the parallel poll can be used to reduce the number of polls required to identify the instrument requiring service Parallel Poll The parallel poll PPOLL is used to allow several instruments to respond with the service request status on a single bus line Since there are eight bus lines up to eight groups of instruments can be polled at the same time By testing the data lines after a parallel poll the group generating a service request can be quickly identified and then the instruments in that group can be serial polled until the instrument s requiring service is located In a system with eight instruments this reduces the number of polls from eight serial polls to one parallel poll and then a single serial poll HP 8673C D Remote Procedure contr d Program Codes gt Comments Operation Detailed Operating Instructions Status Byte and Polling conta The controller assigns a data line and the
405. ter than 49 94 dB below the carrier lt 49 94 dBc Record the measured and actual level Measured n dBe Correction 16 06 dB Actual level dBe 39 Set the spectrum analyzer controls for a resolution bandwidth of 300 Hz and a frequency span per division of 2kHz Using a 300 Hz bandwidth requires a 26 06 dB correction factor 40 Repeat steps 23 through 38 while observing the noise 10 kHz from the carrier Record the results in the table below Frequency Measured Correction Actual Limit 2000 MHz 26 06 dB 6600 MHz 26 06 dB 12 300 MHz 26 06 dB 18 600 MHz 26 06 dB 26 000 MHz 26 06 dB 41 Set the spectrum analyzer controls for a resolution bandwidth of 3 kHz and a frequency span per division of 20 kHz Using a 3 kHz bandwidth requires a 36 06 dB correction factor 42 Repeat steps 23 through 38 while observing the noise 100 kHz from the carrier Record the results in the table below Frequency Measured Correction Actual 2000 MHz ees 36 06 dB 6600 MHz Coleen sere 36 06 dB 12 300 MHz PE ner Dee 36 06 dB 18 600 MHz E 36 06 dB 26 000 MHz Senter eee ere 36 06 dB 4 39 Performance Tests HP 8673C D PERFORMANCE TESTS 4 12 HARMONICS SUBHARMONICS amp MULTIPLES TEST Specification P Electrical Performance Characteristics Characteristics Conditions meevesaravararratsu isis ir aaa nr reni SPECTRAL PURITY Output level lt 3 dBm Harmonics NORMAL mo
406. tered as 1 GHz with the current sweep span defined as 100 kHz the sweep step size will be adjusted to be 100 kHz and a message will be issued However changing the sweep span to 10 GHz will restore the sweep step size to 1 GHz without having to re enter the value The Signal Generator accepts any sweep step size within the range of 1 kHz and the maximum frequency of the Signal Generator Any digits below 1 kHz will be truncated and the entered value may be adjusted to be consistent with the remaining sweep parameters The format of the remote programming follows the front panel key sequence The program code SS or SP is sent followed by the desired sweep step size and the units GHz MHz kHz or Hz 3 147 Operation HP 8673C D Detailed Operating Instructions Remote Procedure cont d Example Program Codes Comments 3 148 Step Size Sweep conra The actual step size can be read by the controller using the output active program code suffix To read the current step size the program string SPOA or SSOA is sent and then the step size and the number of steps must be read Since step size and the number of steps are directly related both are sent when the output active program code suffix is used If read as a string the format is the program code SP followed by the sweep step size in fundamental units Hz and the units terminator Hz a comma and the program code SP followed by the current number of steps and the un
407. terminator The STEPS ms key contains a shifted function XFREQ This function is used as a terminator for the multiplier entry function Entry sequence is SHIFTED START m n STEPS ms The digits m and n represent the multiplier number 199 and may be entered as a single digit TUNE ON OFF Key Enables the TUNE knob when ON disables the TUNE knob when OFF The key indicator lights when it is ON Figure 3 4 Frequency Control Features and LINE Switch 1 of 2 3 10 HP 86738C D Operation LINE Switch Applies power to the Signal Generator when set to the ON position Power is supplied to the reference oscillator oven and the battery charger circuit in the STBY and ON positions TUNE Knob Changes the CW frequency by the value set with FREQ INCR The knob is enabled by the ON OFF key The knob also serves as a manual sweep mode control FREQ INCREMENT WS and A Keys Decreases or increases the CW frequency in steps the increment size is set with the FREQ INCR key Holding either key down causes the frequency to continuously change These keys also serve as a manual sweep mode control In manual sweep the increment size is equal to the sweep step size Figure 3 4 Frequency Control Features and LINE Switch 2 of 2 3 11 Operation HP 8678C D SWEEP FREQ STRT Key Normal operation STRT Used as a prefix to the Data and Units keys to set the beginning fre quency of a sweep Pressin
408. the FREQUENCY MHz display will be adjusted to display the RF output frequency offset by the entered offset frequency When the offset mode is activated the OFFSET front panel annunciator will be lighted to indicate that the actual frequency is not the displayed frequency Entering an offset of zero will deactivate the offset frequency mode An instrument preset will also clear the offset frequency and deactivate offset frequency mode Once the offset frequency is entered all subsequent frequency entries will be adjusted before setting the actual output frequency For a positive offset the actual frequency will be lower then the entered frequency and for a negative offset the actual frequency will be higher than the entered frequency The offset frequency can be programmed to any frequency between 1 kHz and the Signal Generator s maximum frequency Once the offset is programmed frequencies read by the controller will be offset by the current offset frequency Note that all frequencies except sweep step size and sweep frequency span are offset The format of the remote programming uses a program code to specify frequency offset followed by the desired offset frequency and the appropriate units terminator GZ MZ KZ or HZ Entering a negative frequency specifies a negative offset and entering a gt positive frequency specifies a positive frequency offset 3 107 Operation HP 8673C D Detailed Operating Instructions Remote Procedu
409. the sweep start or stop frequency will reset the sweep center frequency if in sweep mode or the CW frequency if sweep is off The frequency span will be recalculated whether sweep is on or off The sweep center frequency or CW frequency will be reset to be halfway between the start and stop frequencies The sweep stop frequency can be set to any valid Signal Generator frequency In addition if the start frequency is set above the stop frequency single and auto sweep modes will still sweep from the start to the stop frequency Manual sweep will start at the lower absolute frequency and move toward the higher absolute frequency To set the Signal Generator to a specific sweep stop frequency Press the SWEEP FREQ STOP key to indicate that the next entry will be for sweep stop frequency 2 Enter the desired frequency using the numeric keypad If a mistake is made while entering the frequency press the backspace key until the incorrect digit disappears Continue entering the correct digits until the frequency displayed in the FREQUENCY MHz display is correct 3 Press the appropriate units key The frequency can be entered in GHz MHz or kHz Once the units key is pressed the displayed frequency will be adjusted to display MHz and the sweep stop frequency will be set The sweep stop frequency will continue to be displayed until the units key is released The actual frequency displayed after releasing the units key will usually not be the ente
410. then be 10 since 0 dB attenuation would be required and the 10 dB range is one step above zero attenuation The following message may be displayed when programming the RF output level 24 The programmed RF output level VERNIER RANGE or both is outside the Signal Generator s range 3 67 Operation HP 86738C D Detailed Operating Instructions Description Local Procedure Remote Procedure Example 3 68 Dwell Time Sweep The Signal Generator performs a sweep by stepping the RF output frequency in discrete steps between the start and stop frequency of the sweep The number of steps that the Signal Generator makes between the start and stop frequency is set by the number of steps or the sweep step size The time that the Signal Generator spends on each step of the sweep is controlled by the dwell time For longer dwell times gt 50 milliseconds the sweep time is approximately equal tothe number of steps multiplied by the dwell time The time required for changing frequency is not included in the dwell time Therefore for shorter dwell times the sweep will take longer than the number of steps multiplied by the dwell time To set the sweep dwell time 1 Press the DWELL key to indicate that the next entry will be for the sweep dwell time 2 Enter the desired dwell time in milliseconds using the numeric keypad Ifa mistake is made while entering the dwell time press the backspace key until the incorrect digit d
411. ther equipment can be substituted if it meets or exceeds these critical specifications 1 5 General Information HP 8673C D Table 1 1 Specifications 1 of 7 NOTE Specifications and characteristics apply after a 1 hour warm up over the temperature range of 0 85 C except specifications for harmonically related spurious signals RF output level pulse peak level accuracy and ampli tude modulation which apply over the range 15 to 85 C after an AUTO PEAK operation has been performed For additional information concerning the use of AUTO PEAK refer to Miscellaneous Capabilities in the Detailed Operating Instructions in Section HI Specifications for output flatness absolute level accuracy and modulation apply only when internal leveling is used Electrical Characteristics Performance Limits Conditions FREQUENCY Range HP 86730 0 05 18 6 GHz 0 01 18 6 GHz overrange HP 8673D 0 05 26 0 GHz 0 01 26 5 GHz overrange Resolution 1 kHz 0 05 to 6 6 GHz 2kHz 6 6 to 12 3 GHz 3 kHz 12 3 to 18 6 GHz 4 kHz 18 6 to 26 0 GHz HP 8673D Accuracy and Stability Same as reference oscillator Reference Oscillator Frequency 10 MHz Aging Rate lt 5 x 107 day After a 10 day warm up typically 24 hours in a normal operating environment Switching Time for frequency lt 50 ms CW and AM modes AUTO PEAK to be within specified resolution disabled NORMA
412. til it is read or the status byte is cleared To sweep from 2 to 4 GHz in automatic sweep mode Local 1 Set the start frequency to 2 GHz and the stop frequency to 4 GHz 2 Dress the AUTO SWEEP MODE key to activate automatic sweeping The key indi cator will blink briefly at the beginning of each new sweep Remote The programming string to set automatic sweep is W2 The alpha character W can be sent as upper or lower case Program Auto Sweep Mode The Signal Generator digital sweep is composed of discrete frequencies that are produced sequentially The minimum step size is limited to the frequency resolution which is defined as the minimum change in frequency that the Signal Generator can produce The number of steps is dependent on the frequency resolution and the frequency span For information regarding sweep time see the DWELL TIME detailed operating instruction The actual change in output frequency during a sweep will not be uniform for some frequency bands and may vary up to 2 kHz This is required to accommodate sweep step sizes that are not exact multiples of the frequency resolution The sweep steps averaged over several sweep points will be equal to the selected sweep step size An example of the averaging is defining a sweep step size of 10 kHz at a start frequency of 15 GHz The minimum tuning increment at 15 GHz is 3 kHz which means that the sweep step size can be 9 kHz or 12 kHz for exact step sizes To o
413. til the external trigger signal is received Using the FREQ INCREMENT keys reset the Signal Generator s frequency to the start frequency 2 000 000 MHz Press the digitizer STORE M1 key on the oscilloscope and then use the appropriate FREQ INCREMENT key to step the Signal Generator to the stop frequency 1 900 000 MHz The oscilloscope should digitize the switching waveform as the frequency changes The waveform should be similar to the waveform shown in Figure 4 13 B rna div 200 mV div Figure 4 13 Frequency Switching Waveform 10 Set the oscilloscope to delayed sweep mode 11 Using the digitized signal displayed on the oscilloscope measure the time to the point at which the IF frequency amplitude suddenly increases and remains more than 1 division peak to peak Set the oscilloscope s delay time to the measured time 12 Using the FREQ INCREMENT keys reset the Signal Generator s frequency to the start frequency 4 30 HP 86738C D Performance Tests PERFORMANCE TESTS FREQUENCY SWITCHING TIME TEST contd Procedure 13 Press the digitizer STORE M1 key on the oscilloscope and step the Signal Gener contd ator to the stop frequency with the appropriate FREQ INCREMENT key The oscilloscope should digitize the switching waveform as the frequency changes The waveform should now look like that shown in Figure 4 14 200 mV div Figure 4 14 Frequency Switching Time Measurement Waveform
414. tor s LINE switch to STBY then back to ON How ever this technique has some disadvan tages a It defeats the purpose and advan tage of local lockout that is the system controller loses control of a system element b There are several HP IB conditions that reset to default states at turn on 3 27 Addressing The Signal Generator interprets the byte on the eight HP IB data lines as an address or a bus command if the bus is in the command mode The command modeis defined as attention control line ATN true and interface clear control line IFC false Whenever the Signal Generator is addressed if in local or remote either the TLK or LSN annunciator on the front panel turns on The Signal Generator s Talk and Listen addresses can be set from switches located inside the instru ment or from the front panel The address selec tion procedure is described in Section II 3 34 The decimal equivalent of the addresses can be displayed in the FREQUENCY MHz display by pressing and holding the LOCAL key This is the decimal equivalent of the last five bits of both the Talk and Listen ASCII address codes Refer to Table 2 1 for a comprehensive listing of all valid HP IB address codes Listen Only Mode If the internal Listen Only switch is set to 1 the Signal Generator is placed in the Listen Only mode The instrument then responds to all Data messages and the Trigger Clear and Local Lockout messages It can also
415. troller should be instructed not to accept the linefeed character decimal 12 as an early termination of the data transfer The correct format for the HP 9000 Series 200 and 300 or the HP 85 controllers is ENTER 719 USING B B S1 S2 The following programs are written in BASIC for HP 9000 Series 200 or 300 controllers The program below is used to test for the SOURCE SETTLED bit after a frequency or level change Since the SOURCE SETTLED bit is not set for some program codes a timeout is provided to terminate the subroutine 10 SUB Source_settled 20 Time_in TIMEDATE Reference for timeout 30 Check_it 40 V SPOLL 719 Take a serial poll to check the bit 50 Check for set bit or more than 3 seconds 60 IF NOT BIT V 3 AND TIMEDATE Time_in lt 3 THEN GOTO Checkit 70 SUBEND gt 3 seconds or bit is set HP 86738C D Programming Example contd Error Messages Operation Detailed Operating Instructions Status Byte and Polling conta The parallel poll is set up using the Request Mask and the parallel poll commands of the controller The following program sets up a parallel poll to check for entry errors or changes in the extended status The parallel poll response will e positive and set for line 1 of the HP IB bus The second subroutine is used to test the HP IB with a parallel poll and call a user subroutine Err_8673 it the poll indicates an SRQ by the HP 8673 100 SUB Set_8673_poli 110 Mask 4 32 Bits
416. tude the final level The oscilloscope is calibrated to display the 1 dB points about the final level The switching time is the time required before the IF signal amplitude remains within the reference levels NOTE Due to the mechanical attenuator that is switched during level changes a digitizing oscilloscope should be used to store and view the level switching process The test may be performed without a digitizing oscil loscope by repetitively switching the level and frequency of the unit under test but care should be taken to ensure that the number of level changes needed for the measurement are minimized Crystal Detector HP 8473C Digitizing Oscilloscope HP 1980B 19860A Controller eee HP 85B or HD 9836A HP 8673C D SYNTHESIZED SIGNAL GENERATOR BLANK I NG MARKER CONTROLLER OSCILLOSCOPE CHANNEL 1 EXTERNAL TRIGGER Figure 4 23 Output Level Switching Time Test Setup 4 59 Performance Tests HP 8673C D PERFORMANCE TESTS OUTPUT LEVEL SWITCHING TIME TEST cont d Procedure 1 con d 2 4 60 Set up the equipment as shown in Figure 4 23 The external trigger input of the oscilloscope is connected to the Signal Generators rear panel Blanking Marker output This signal will trigger the oscilloscope at the start of a frequency change when any sweep mode is selected By making a simultaneous frequency and level change the oscilloscope can be t
417. udio source The modulated signal is mixed with a local oscillator to produce a modulated 100 MHz IF signal The AM depth meter accuracy and accuracy relative to the external AM input are measured on a measuring receiver Equipment Local Oscillator HP 8340A Measuring Receiver HP 8902A Audio Analyzer Source HP 8903B Digital Voltmeter HP 3455A 6 dB Attenuator HP 8493C Option 006 IOT eck chon aT tie RHG DMS1 26 HP 8673C D SYNTHESIZED SIGNAL GENERATOR LOCAL OSCILLATOR AUDIO ANALYZER SOURCE RF OUTPUT DIGITAL VOLTMETER MEASURING RECEIVER MODUL AT iON OUTPUT Figure 4 33 AM Accuracy Test Setup Procedure 1 Connect the equipment as shown in Figure4 38 4 78 HP 8673C D Performance Tests PERFORMANCE TESTS AM ACCURACY TESTS cont d Procedure 2 Set the Signal Generator as follows cont d FREQUENCY ciiciaritydiss das tunnes 1 95 GHz OUTPUT LEVEL RANGE 0 dB OUTPUT LEVEL VERNIER 0 dBm IH INT PIV AEAEE ee oe rat 100 range EM aeaee are aa op Soke A OFF 3 Tune the local oscillator to 2 0 GHz at an output amplitude of 8 dBm 4 Select AM mode on the measuring receiver 5 Set the modulation source to 1 kHz Adjust the output level to obtain 50 AM as read on the measuring receiver 6 The AM meter on the Signal Generator should indicate 50 AM 8 5 Record the reading AM Meter reading 41 5 _ BH Bn Accuracy Re
418. ulation The automatic execution of the AUTO PEAK func tion by the instrument s internal microprocessor ensures that key power and pulse specifications are met for nearly all circumstances see Section 3 12 Three conditions that may necessitate a user acti vated AUTO PEAK are load changes extreme frequency changes and in rare circumstances frequency changes slightly less than 50 MHz a Changes of load impedance can shift the cen ter frequency of internal filters and necessitate another AUTO PEAK operation This could occur if highly reactive loads are switched in and out in automatic test systems b Large frequency changes cause extreme changes in the self heating of internal YIG filters Although most of the resulting drift occurs in 15 20 seconds complete settling may take up to 15 minutes Some experimentation may be needed to determine when AUTO PEAK is necessary for this type of measurement c Finally on rare occasions pulse overshoot parameters may drift out of specified range for frequency changes just less than 50 MHz To be confident of obtaining warranted instru ment performance perform an AUTO PEAK oper ation just before each measurement is taken Another automatic instrument function deter mines the optimum injected pulse amplitude to the YTM This occurs during an AUTO PEAK opera tion and for vernier power level changes 0 4 dB During this operation the instrument switches briefly to CW for abo
419. ult Table 3 8 Error Messages or the pull out card for an explanation of the error codes The error code will remain in the FREQUENCY MHz display as long as the MESSAGE key is pressed Once the message is read however the error code is cleared to 00 no error whether or not the causing condition has been corrected Types of error codes Messages 01 through 09 are front panel entry errors The entry is ignored and the previous parameter value is retained Messages 10 through 16 are errors that result from unusual combinations of sweep entries A message is displayed and all entered values are stored in anticipation that further entries will resolve the conflict Messages 30 through 90 are service related errors This type of error message should be referred to service trained personnel See Section 8 in the Service Manual for more information To read the error code 1 Press and hold the front panel MESSAGE key to read the two digit error code 2 Refer to Table 3 8 Error Messages or the pull out card for an explanation of the error codes Error messages can be read using the HP IB To do so send the program code MG to the Signal Generator then read back the two digit error code 00 to 99 Refer to Table 3 8 Error Messages or the pull out card for an explanation of the message codes Error messages are not cleared in remote mode by sending new program strings To ensure correct error messages clear MESSAGE by reading t
420. ument is being returned to Hewlett Packard for service please complete one of the blue repair tags located at the back of this manual and attach it to the instrument Original Packaging Containers and materials identical to those used in factory packaging are available through Hewlett Packard offices Mark the container FRAGILE to assure careful han dling In any correspondence refer to the instru ment by model number and full serial number Installation Other Packaging The following general instruc tions should be used for re packaging with com mercially available materials a Wrap the instrument in heavy paper or plastic df shipping to a Hewlett Packard office or service center complete one of the blue tags mentioned above and attach it to the instrument b Use a strong shipping container A double wall carton made of 2 4 MPa 350 psi test material is adequate c Use enough shock absorbing material 75 to 100 mm layer 3 to 4 inches around all sides of the instrument to provide firm cushion and prevent movement in the container Protect the front panel with cardboard d Seal the shipping container securely e Mark the shipping container FRAGILE to assure careful handling Installation HP 86738C D oh NI SIGNAL GROUND P O TWISTED PAIR WITH 11 PIO TWISTED PAIR WITH 10 SHOULD BE GROUNDED P O TWISTED PAIR WITH 9 A OED Witt A P O TWISTED PAIR WITH 8 TWISTED PAIR PJO TWISTED PAIR W
421. ut Normal Mode HP 8678C HP 8673D Bypass Mode HP 86730 HP 8673D Performance Limits lt 46 dBe lt 58 dBe DD dBc lt 74 dBe lt 98 dBe lt 35 dBe lt 60 dBe lt 60 dBc lt 60 dBc lt 60 dBc lt 70 dBc lt 64 dBe lt 60 dBe lt 58 dBe lt 50 dBe lt 60 dBe lt 65 dBc lt 44 dBe lt 54 dBe BD dBe lt 40 dBc lt 50 dBe lt 55 dBc lt 38 dBc lt 48 dBe lt 53 dBe 11 dBm to 100 dBm 5 dBm to 100 dBm 2 dBm to 100 dBm 6 dBm to 100 dBm 8 dBm to 100 dBm 5 dBm to 100 dBm 7 dBm to 100 dBm Table 1 1 Specifications 2 of 7 General Information Conditions 10 Hz offset from carrier 100 Hz offset from carrier 1 kHz offset from carrier 10 kHz offset from carrier 100 kHz offset from carrier 0 05 to 1 2 GHz 1 2 to 18 26 GHz HP 8673C 1 2 to 26 GHz HP 8673D 0 05 to lt 2 0 GHz 2 0 to 6 6 GHz gt 6 6 to 12 3 GHz gt 12 3 to 18 6 GHz gt 18 6 to 26 0 GHz HP 8673D lt 300 Hz offset from carrier 300 Hz to 1 kHz offset from carrier gt 1 kHz offset from carrier lt 300 Hz offset from carrier 300 Hz to 1 kHz offset from carrier gt 1 kHz offset from carrier lt 300 Hz offset from carrier 300 Hz to 1 kHz offset from carrier gt 1 kHz offset from carrier lt 300 Hz offset from carrier 300 Hz to 1 kHz offset from carrier gt I kHz offset from carrier 0 05 t
422. ut 200 us Pulse mode is then re enabled and the injected pulse amplitude is the correct value to produce fast risetime pulses Fre quency switching speed is slowed to about 100 ms by this process 3 6 HP 8673C D Ifthese bursts of CW power are objectionable they can be eliminated by exploiting the following fea ture At any one frequency when the vernier is used to change the output power level by more than 0 4 dB a scratch pad memory stores the correct injected pulse amplitude for that power level Subsequent operation at that power level uses the scratch pad data instead of switching to CW to update the pulse control parameters By sweeping over the entire 10 to 10 dBm power range for each frequency of operation the scratch pad memory will contain all the necessary data for pulse operation at any power level and no further switching to CW will occur at that frequency 3 16 SWEEP Mode in MASTER SLAVE Configuration In a Master Slave configuration two signal gener ators are interconnected to obtain two swept micro wave signals at a fixed offset from each other The two instruments are interconnected through the Hewlett Packard Interface Bus HP IB The MASTER is set to HP IB address 50 and the SLAVE unit is set to HP IB address 40 The desired sweep start and stop frequencies are set to identical frequencies on both the master and slave instru ments Desired offsets are then entered on the slave un
423. utput level to obtain 30 AM as cont d read on the measuring receiver 5 Select FM mode on the measuring receiver Incidental FM should be less than 4 kHz Record the results in the table below 6 Repeat steps 1 through 4 with a Signal Generator frequency of 1000 MHz Record the results in the table below Signal Generator incidental FM Frequency Level Actual Limit 200 MHz 0dBm ee ee 4 kHz 1000 MHz 0dBm 4 kHz 7 Connect the equipment as shown in Figure 4 35 HP 8673C D SYNTHESIZED SIGNAL GENERATOR LOCAL OSCILLATOR AUDIO ANALYZER SOURCE OUTPUT INPUT RF AM IN RF QUTPUT OUTPUT 6 dB DIGITAL VOLTMETER MEASURING RECEIVER MODULATION OUTPUT Figure 4 35 incidental FM Test Setup Part Two 8 Set the Signal Generator as follows FREQUENCY iar0 dca te da or conden een 6 2 GHz OUTPUT LEVEL RANGE 0 dB OUTPUT LEVEL VERNIER 0 dBm ACO a KER cha Ee A T R Na INT AM oor wR VS esd Owen SECM Rats ww eN 100 range BM recie a tay AAA e RE E ax OFF 9 Tune the local oscillator to 6 1 GHz with an output amplitude of 7 dBm 4 82 HD 8673C D Performance Tests PERFORMANCE TESTS INCIDENTAL FM contd Procedure 10 Select AM mode on the measuring receiver contd 11 Set the modulation source to 10 kHz Adjust the output level to obtain 30 AM as read on the measuring receiver 12 Select FM mode on the measuring receiver The incidental FM indicated on the me
424. vel The range may have to be adjusted to compensate for losses and gains in the RF signal path If the RF signal path will have a relatively high loss a higher Signal Generator range will be required 4 Connect the recorder output of the power meter to the external ALC input of the Signal Generator The recorder output signal typically varies from 0 to 2 Vdc for each power meter range corresponding to a 23 dB dynamic range 5 Press the ALC PWR MTR key to set the Signal Generator to external power meter ALC mode HP 8673C D Operation Detailed Operating Instructions Power Meter Automatic Level Control contra Local 6 Adjust the ALC CAL control on the Signal Generator front panel until the Procedure UNLEVELED annunciator is extinguished Set the Signal Generator VERNIER cont d for a0 dBm indication on the Signal Generator level meter Continue adjusting the CAL control until the power meter indicates a level that is in the desired leveling range and lower than the VERNIER setting by the coupling factor For example for a desired level in the range of 17 to 10 dBm using a 10 dB directional coupler adjust the CAL control for a power meter reading of 20 dBm A more accurate calibration can be made using another power meter at the output of the directional coupler This will eliminate a possible error due to the coupling factor and will give greater assurance that the output of the coupler is accurate Once the calibration is c
425. weep mode For a more complete description of the messages see the MESSAGES detailed operating instruc tions 10 Thestart and stop frequency are set to the same value No sweep will be generated 11 The current sweep span is set such that the start frequency would be below the frequency range of the instrument The sweep will begin at the lowest sweep point that is within the range of the Signal Generator All sweep points will be allotted but the frequency will not change until the sweep is within the frequency range of the Signal Generator 12 The current sweep span is set such that the stop frequency would be above the frequency range of the instrument The sweep will end at the highest sweep point that is within the frequency range of the Signal Generator All sweep points will be allotted but the last sweep points will all be at the highest valid frequency 16 A filter or amplifier band crossing occurred during automatic sweep mode Only one sweep will occur and then the sweep will stop Filter switch points may be bypassed by using BYPASS mode 90 Auto Peak malfunction This indicates that the instrument may require service HP 86738C D Description Local Procedure Remote Procedure Operation Detailed Operating Instructions Start Frequency Sweep The sweep start frequency determines where the Signal Generator will begin asweepin each of the three sweep modes The sweep frequency limits are determined by setting eith
426. wer levels between the maximum leveled power and 20 dBm are within specification Power levels of 30 dBm and below are checked using a spectrum analyzer The output level of the Signal Generator is adjusted to 20 dBm using the power meter The Signal Generator output is mixed with a local oscillator to 4 52 HP 8673C D Performance Tests PERFORMANCE TESTS ABSOLUTE LEVEL ACCURACY TESTS cont d Description produce an IF frequency The IF frequency is displayed on the spectrum analyzer A cont d reference level corresponding to the 20 dBm output is set on the spectrum analyzer and each 10 dB decrease in range is checked for a 10 dB decrease on the spectrum analyzer display Equipment Power Meter a HP 436A Power Sensor cues HP 8485A Local Oscillator HP 8340A Waker 4 ci eea ies eee a aa RHG DMS1 26 Spectrum Analyzer HP 8566B 40 dB Amplifier iss kcaeen HP 8447F 20 dB Attenuator HP 8493C Option 020 HP 8673C D SYNTHESIZED SIGNAL GENERATOR LOCAL OSCILLATOR RF OUTPUT RF OUTPUT 20 dB STEP 24 ATTENUATOR STEP 1 IF SPECTRUM ANALYZER POWER SENSOR 40 dB AMPLIFIER POWER METER OUTPUT Figure 4 22 Absolute Level Accuracy Test Setup Procedure High Level Accuracy Test 1 Connect the equipment as shown in Figure 4 22 2 Zero and calibrate the power meter Set the power meter to dBm mode 3 Tune the Signal Generator to 50 MHz
427. wing HP IB controller program HP 8678C D Performance Tests PERFORMANCE TESTS OUTPUT LEVEL SWITCHING TIME TEST cont d Procedure 10 L2 0 contd 20 FOR i 1 TO 20 30 OUTPUT 719 LE L2 1 DB 40 NEXT 50 FOR l 1 TO 20 60 OUTPUT 719 LE L2 1 DB 70 NEXT 80 GOTO 20 90 T NEXT PROGRAM 100 Li 99 110 L2 0 120 OUTPUT 719 LE L1 DB UP 130 PRINT PLEASE PRESS THE DIGITIZER KEY 140 PRINT PRESS THE CONTINUE KEY ON THE 150 PRINT CONTROLLER WHEN DONE 160 PAUSE 170 OUTPUT 719 DN LE L2 DB 180 END 7 While the program is executing adjust channel 1 vertical controls for an amplitude change of exactly two divisions centered about the middle horizontal graticule This calibrates the display for a 1 dB reference about 0 dBm 8 Set the oscilloscope s main sweep mode to triggered or NORM This sweep mode will not trigger the digitizer until the external trigger signal is received 9 Press the pause key on the controller to stop the first part of the program Run the second part of the program by executing the statement RUN 100 Press the digitizer key on the oscilloscope when instructed to by the program The program will set the output level to the starting value L1 and step the frequency up The program will then pause to allow the digitizer key on the oscillo scope to be pressed After the key is pressed the program triggers the oscilloscope as the level is swit
428. witched to standby then on again Operation Special Function Learn Mode This mode is in tended for servicing the Signal Generator It is similar in operation to the front panel learn mode After receiving an L2 program code Special Func tion Learn Mode and when addressed to talk the Signal Generator sends 2 ASCII characters and 9 followed by a string of 26 8 bit binary bytes This binary data can then be stored in the controller s memory The binary characters are directly related to the digital outputs of the Signal Generator s internal controller There is no checksum or other error detecting scheme allowing diagnostic and other special functions that are not normally possible with the Signal Generator Refer to Section VHI Service for additional information Messages This function enables the MESSAGE key to be read under program control After receiv ing an MG program code Message and when addressed to talk the Signal Generator sends a two digit number coded in ASCII followed by a Line Feed LF and EOI The codes represent entry errors and instrument malfunctions The two digit codes are explained on the operating infor mation pull out card and in the Message Detailed Operating Instruction The Message can always be read by pressing the MESSAGE key even when the Signal Generator is in remote mode However reading the Message once either in remote or local clears it to 00 No Error whether or not the causi
429. xample 16 GHz divided by three itis between 12 3 and 18 6 GHz is 5 333333 33 kHz Since the dividend is nota whole number this frequency cannot be set exactly The nearest frequencies that can be set are 15 999999 GHz 5 333333X8 and 16 000002 GHz 5 333334X3 Note that the roundoff error is only 1 kHz if 15 999999 GHz is programmed instead of 16 GHz Frequencies above 6 6 GHz are produced by multiplying the baseband frequency 2 0 6 6 GHz The time it takes to switch from one frequency to another depends on the largest baseband lt 6 6 GHz frequency digit being changed Generally the smaller the digit being changed the shorter the switching time For example a change of 3 kHz the 1 kHz digit would be faster than a change of 3 GHz the 1 GHz digit Typical switching times by largest digit being changed for frequencies less than 6 6 GHz can be summarized as follows HP 8673C D Comments cont d Operation Detailed Operating Instructions Frequency CW conta Largest Digit Time to be Changed Within 1 kHz For frequency changes involving frequencies above 6 6 GHz the actual frequency digits being changed must be determined by dividing the frequency change by two 6 6 to 12 3 GHz three 12 3 to 18 6 GHz or four 18 6 to 26 5 GHz The result will indicate which digits of the fundamental unmultiplied frequency will actually change The frequency switching time will depend only on which digits of the baseband frequen
430. xternal AM Input Frequency Rate 6 6 GHz 10 kHz 79 9 ee Ee 100 1 6 6 GHz 1 kHz 79 9 P 100 1 6 6 GHz 0 1 kHz 79 9 ON AA EEE OE 100 1 10 GHz 10 kHz 79 9 ieee amar 100 1 14 GHz 10 kHz 79 9 a eee be 100 1 HP 8673D only i 18 6 GHz 10 kHz 79 9 2 eel ee 100 1 22 0 GHz 10 kHz 79 9 ace ss es 100 1 HP 8673C only 18 6 GHz 10 kHz 79 9 ear ee eee 100 1 EXTERNAL FM ACCURACY AND METER ACCURACY Meter Accuracy Full Scale 255 kHz DE eae a Nerang on 345 kHz 50 kHz 35 kHz ee eae ae eee 65 kHz Accuracy Relative te External FM Input 0 03 MHz Range 27 kHz Aironet Seana 33 kHz 0 1 MHz Range 90 kHz e 110 kHz 0 3 MHz Range 270 kHz Pa et See re es 330 kHz 1 0 MHz Range 249 kHz Ta E aaa 351 kHz 0 3 MHz Range Accuracy 6 7 GHz 270 kHz nese oe Seer 330 kHz 12 3 GHz 270 kHz E A en ED 330 kHz 18 6 GHz 270 kHz EI ESE EEA 330 kHz 4 22 HP 8673C D Performance Tests PERFORMANCE TESTS 4 8 FREQUENCY RANGE AND RESOLUTION TEST Specification Description Equipment Procedure Electrical Performance Characteristics Characteristics Conditions FREQUENCY Range HP 8673C 0 05 18 6 GHz 0 01 18 6 GHz Overrange HP 8673D 0 05 26 0 GHz 0 01 26 5 GHz Overrange Resolution 1 kHz 2 0 to 6 6 GHz 2 kHz 6 6 to 12 3 GHz 3 kHz 12 3 to 18 6 GHz 4kHz 18 6 to 26 0 GHz This test checks the tuning resolution in each of four internal frequency bands using a frequency counter The performance test is divided
431. y for levels between 10 and 3 dB of the RANGE The program code used to set the ALC mode to internal is C1 Once the Signal Generator is set to internal ALC mode the output level can be set and read directly by the control ler Internal ALC is set when the instrument is preset The VERNIER and RANGE settings and the RF output level the sum of RANGE and VERNIER can be read using the output active program code suffix To read the VERNIER setting 12 0 to 3 0 dBm send the program string VEOA and then read _ the VERNIER setting using the ENTER command The Signal Generator will send the setting in units of dBm Ifthe setting is read as a string the format will be the program code VE followed by the VERNIER setting in dBm and then the units code DM The RANGE setting is read by sending the program string RAOA and then reading the RANGE setting using the ENTER command The Signal Generator will send the range in units of dBm 90 to 10 Ifthe RANGE setting is read as a string the format will be the program code RA followed by the range setting in dBm and then the units code DM The RF output level is read by sending the program string LEOA and then reading the output level The Signal Generator will send the level in units of dBm 102 to 13 0 If the RF levelis read as a string the format will be the program code LE followed by the RF output level in dBm and then the units code DM The program code AP or PLcan be used instead
432. z Local 1 Press the SWEEP FREQ START key 2 Key in 16232 334 using the numeric keypad The FREQUENCY MHz display should show 16232 334 when you have finished keying in the value Note that the entry is left justified at this point 3 Press the MHz units key to finish the sequence The FREQUENCY MHz display should show the entered frequency until the units key is released The FREQUENCY MHz display should now be right justified The frequency could also have been entered as 16 232334 GHz or 16232334 kHz The only difference is the placement of the decimal point and the units key pressed after the frequency has been entered using the numeric keypad Remote The programming string for setting the sweep start frequency is composed of a program code numeric data and the units terminator The frequency may be programmed in units of GHz MHz kHz or Hz To program the Signal Generator start frequency to 16232 334 MHz the possible program strings are FA16 232334GZ or FA16232 334MZ or FA16232334KZ or FA16232334000HZ The alpha characters can be sent as upper or lower case or even mixed upper and lower case If the CW frequency changes the output frequency is valid once the SOURCE SETTLED bit of the status byte is set see Comments HP 86738C D Program Codes Comments Operation Detailed Operating Instructions Start Frequency Sweep conra Program Applicable Function Code Units Start Fr
433. z 1 50 ms 6 0 to 2 1 GHz 50 ms 6 5 to 2 1 GHz 50 ms 6 49 to 2 2 GHz 50 ms 1 9 to 3 0 GHz 50 ms 2 2 to 6 49 GHz 50 ms 2 1 to 6 5 GHz 50 ms 6 61 to 6 59 GHz 50 ms 6 59 to 6 61 GHz 50 ms 3 999 to 12 4 GHz 50 ms HP 8673D only 19 5 to 2 1 GHz 50 ms 26 0 to 2 1 GHz 50 ms 2 1 to 19 5 GHz 50 ms 2 0 to 26 0 GHz 50 ms 2 1 to 26 0 GHz 50 ms Amplitude Recovery 2 0 to 6 6 GHz 50 ms 6 601 to 12 3 GHz 50 ms 3 0 to 4 0 GHz 50 ms 4 0 to 10 0 GHz 50 ms HP 8673D only 12 301 to 18 6 GHz 50 ms 18 601 to 26 0 GHz 50 ms 2 0 to 26 0 GHz 50 ms 6 601 to 26 0 GHz foo Onis 2 0 to 18 6 GHz See eee 50 ms 4 11 SINGLE SIDEBAND PHASE NOISE 30 Hz offset from carrier 1 999 960 MHz Ka 64 dBe 6600 GHz 64 dBc 12 300 GHz 58 dBe 18 600 GHz 54 dBe HP 8673D only 26 000 GHz 52 dBe H 100 Hz offset from carrier 1 999 960 MHz eee 70 dBe 6600 GHz er ees 70 dBe 12 300 GHz lg een 64 dBe 18 600 GHz ee aici 60 dBe HP 8673D only 26 000 GHz a 58dBe 4 92 HD 8673C D Performance Tests Table 4 4 Performance Test Record 3 of 13 Results i dE Test No Min Actual Oo 4 1 SINGLE SIDEBAND PHASE NOISE cont d 1 kHz offset from carrier 1 999 960 MHz pe eee 78 dBe 6600 GHz aT eee 78 dBe 12 300 GHz Beste testes 72 dBe 18 600 GHz a 68 dBe HP 8678D only 26 000 GHz 66 dBc 10 kHz offset from carrier 1 999 960 MHz L 86 dBe 6600 GHz a 86 dBe 12 300 GHz a 80 dBe 18 600 GHz 70 dB
434. z will produce an actual frequency of 3 GHz To enter a frequency display multiplier 1 Press the blue shift key to access the shifted key functions 2 Press the MULT shifted STRT key to indicate that the next entry will be for display multiplier 3 Enter the desired display multiplier using the numeric keypad The FREQUENCY MHz display should display the entry 4 Press the X FREQ units key to finish the entry The display multiplier will be displayed until the X FREQ key is released Once the key is released the FREQUENCY MHz display will indicate the multiplier value times the previous display For example if the Signal Generator RF output frequency was 3 GHz before the multiplier was entered and the multiplier is three the display will indi cate 9 GHz The multiplier annunciator will be lighted to indicate that the displayed frequency is an integer multiple of the actual output frequency Entering a multiplier of 1 will disable the frequency multiplier mode Valid entries are 1 to 99 For some sweep displays the least significant digits may be truncated due to insufficient space to display large frequencies corresponding to large frequency display multipliers l Entering a frequency with a display multiplier active will display the entered frequency The actual frequency at the RF output will be the displayed frequency divided by the multiplier The program code for display multiplier is MY The programming format follows th
435. ze in the 3 kHz resolution frequency band Sweeps from a higher frequency to a lower frequency can be accomplished by setting the start frequency higher than the stop frequency This combination results in a negative frequency span as indicated when the frequency span is displayed Negative frequency spans can only be entered by setting the start frequency higher than the stop frequency An Auto Peak operation is performed whenever the RF output frequency is more than 50 MHz from the frequency at which the last Auto Peak operation was performed The Auto Peak operation optimizes the Signal Generator performance at the current frequency The Auto Peak operation produces small changes in the RF output level as the peaking is performed For applications requiring fastest sweeps Auto Peak may be disabled However with Auto Peak disabled modulation performance and maximum output power may be degraded The time required for the Auto Peak operation is not included in the dwell time setting The Automatic Level Control ALC bandwidth is increased when sweep mode is activated This provides fast response to switching transients when sweeping In addition activating sweep mode while amplitude modulating increases the usable AM bandwidth by about 250 times See the amplitude modulation detailed operating instructions for more information about AM bandwidth while in sweep mode The front panel annunciators are filtered in sweep mode to prevent false indic

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