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TM 11–6625–2781–14–6

1. es E 5 8555A INTERFACE PIO 2 COAXIAL BAND CODE BITS SWITCH A B D E CONTROL AND DRIVER Al PREDRIVER A3 YIG DRIVER 0 EON 71 1 095 SWEEP TUNE GHz V SUMING M 510 0 PIO DRIVER AS Kl _ 71 NOTE 2 L L _ MUN PIO A2 LOGIC DECODER CIRCUITS REMOTE TUNING O AMPL FREQ OFFSET TRACKING FREQ OFFSET NOTES l l OPTION 004 DELETES 1 8 GHz LP FILTER AND ui nc n e T pee COAXIAL SWITCHING RELAYS SWITCH DRIVER i exce ene sssi zs REMAINS BUT IS UNUSED 2 RELAY CONTACTS CLOSED AS SHOWN WITH 8555A HARMONIC SUMMING CABLE DISCONNECTED WITH TUNE VOLTAGE NUMBER AMPL 0 18 450V 8555A OFF OR WITH OPTION 002 SET TO REMOTE 3 UNSHADED CIRCUITS ADDED IN OPTION 003 INSTRUMENTS 7 5 0 15V AMPL AUS L DECODER CIRCUITS BAND CODE BIT NOTE 3 C Tuc ys Figure 8 5 Block Diagram of Standard 8445B With Option 008 Circuits Unshaded e Q Q N N N N N N N N N 1 8 GHz LP LC FILTER TUNI NG CONTROL LPN x REMOTE 41 0 VIGHz N 8555A INTERFACE BAND CODE BITS COAXIAL SWITCH A B D E CONTROL AND Al PREDRI VER 1005 HARMONIC SWEEP TUNE NUMBER SUMMING 5 TO 10 V AMPL AMPL AlUl Alu BAND LOGIC DECODE
2. pite Ls Pob FREQUENCY Ecce eee S 1800 MHz Adjust Signal Generator output level for an indication of 5 dBm on Power Meter Connect Signal Generator output through the 10 dB attenuator to Preselector INPUT Connect Power Meter and Power Sensor to Preselector OUTPUT Adjust Power Supply Fine Voltage control for maximum power level indication on Power Meter Adjust Preselector FREQ OFFSET control for maximum power level indication on Power Meter NOTE Indicated power meter level should correspond with the insertion loss indicated on Preselector calibration label Typically 4 dB below the level established in step 2 above Note and record level indicated on Power Meter Remove 10 dB Attenuator from Signal Generator to Preselector path and install in Preselector to Power Sensor path Note and record level indicated on Power Meter _ dBm Record compression loss difference between levels recorded in steps 9 and 7 above Compression should be less than 1 dB dB 11 6625 2781 14 6 Model 8445B Table 4 1 Performance Test Record Hewlett Packard Model 8445B Tests Performed by Preselector Serial No Date Para Test Minimum No OUT OF BAND REJECTION 4 Reference Frequency 7 Measurement Frequency 12 Out of Band Rejection LOW PASS FILTER INSERTION LOSS 3 Reference Level 6 Insertion Loss 2 5 dB 8
3. 30 MHZ Centered BANDWIDTH 100 kHz SCAN WIDTH PER DIVISION SCAN WIDTH PER DIVISION 10 MHz INPUT ATTENUATION 10 dB SIGNAL IDENTIFIER OFF BASE LINE CLIPPER CCW SCAN TIME PER DIVISION 10 MILLISECONDS LOG LINEAR 10 dB LOG LOG REF LEVEL LOG REF LEVEL Vernier 0 VIDEO OFF SCAN SCAN TRIGGER LINE C Connect Spectrum Analyzer CAL OUTPUT to its own INPUT d Adjust FREQUENCY to align LO feed through signal on the 3 graticule line Check level of 30 MHz signal at CENTER FREQUENCY line Singal level should be 30 dBm Perform AMPL CAL Adjustment if signal level is incorrect See 8555A Operating and Service Manual NOTE Preselectors with Option 004 do not have low pass filters installed Disregard steps f g h and i f Connect Spectrum Analyzer CAL OUTPUT to INPUT port on Preselector g Connect OUTPUT port of Preselector to Spec trum Analyzer INPUT 4 1 TM 11 6625 2781 14 6 h Check level of 30 MHz signal at CENTER FREQUENCY graticule line There should be little change in level of the 30dBm signal through the low pass filter in the Preselector i Select BAND n 1 IF 550 GHz Note that there is an audible dick from coaxial switches in the Preselec
4. HP 435A 8481A Spectrum HP 8555A 8552 141T Sweep lt HP 8620A 86290A Power Supply curia s a sassa REO dan a e dn oe eda eae HP6205B Coaxial Cable BNC toalligator HP 10501A Coaxial Attenuator 10 HP 8491B Option 010 4 7 TM 11 6625 2781 14 6 PERFORMANCE TESTS 4 19 YIG FILTER INSERTION LOSS TEST Cont d 1 4 8 Connect test setup as indicated in Figure 4 3 and make the following control settings PRESELECTOR with manual controls LINE OFF ON iiis ERR ER ERR RE RE pan bea ON MODE PC Em REMOTE PRESELECTOR without manual controls ON Interconnect Disconnected POWER SUPPLY Output Voltage esie cx e Cre E Rae 44 0 Vdc SWEEP OSCILLATOR LINE yasaq E are KR ER ke RERO ERROR RR RE RECO ON CW EUEN upaqa pawasqa da adt Rei Qe ee tee ere eT eee DeL d ee 4 0 GHz CW Pushbutton r Depressed setis deci dan da ibo dades aed aqaa INT POWER LEVEL 55 te le
5. RECOMMENDED CHANGES TO EQUIPMENT TECHNICAL MANUALS SOMETHING WO ING mmu FROM YOUR UNIT S COMPLETE ADDRESS THEN JOT DOWN THE DOPE ABOUT IT ON THIS FORM TEAR IT OUT FOLD IT AND DROP IT IN THE MAIL PUBLICATION NUMBER DATE TITLE BE EXACT PIN POINT WHERE IT 15 IN THIS SPACE TELL WHAT IS WRONG AND WHAT SHOULD BE DONE ABOUT IT TEAR ALONG DOTTED LINE e EDD E ouo EMEN 7 2 AUG 2028 Y OF T A FILL IN YOUR UNIT S ADDRESS FOLD BACK di DEPARTMENT OF THE ARMY POSTAGK AND FEES PAID DEPARTMENT OF THE ARMY OFFICIAL BUSINESS 314 UEMA PENALTY FOR PRIVATE use 200 Commander US Army Communications and Electronics Materiel Readiness Command ATTN DRSEL ME MQ Fort Monmouth New Jersey 07703 FOLD BACK REVERSE OF DA FORM 2028 2 SNITGOZIIOG ONOTV YUVAL ei RECOMMENDED CHANGES TO EQUIPMENT TECHNICAL MANUALS SOMETHING WRONG mm mac FROM YOUR UNIT S COMPLETE ADDRESS THEN JOT DOWN THE DOPE ABOUT IT ON THIS FORM TEAR IT OUT FOLD IT AND DROP IT IN THE MAL PUBLICATION NUMBER DATE TITLE TM 11 6625 2781 14 6 30 Nov 78 BE EXACT PIN POINT WHERE IT 15 IN THIS SPACE TELL WHAT IS WRONG AND WHAT SHOULD BE DONE ABOU
6. RN 28 349 4 Kilograms 0 454 Short Metric 0 907 Newton Meters 1 356 Pounds Square Inch Kilopascals 6 895 Miles per Gallon Kilometers per Liter 0 425 Miles per Hour qne i Kilometers per Hour 1 609 TO CHANGE TO MULTIPLY BY Centimeters In heg z de cede of 0 394 coole dv erii HY i oiv Qua ty a ak 3 280 Meters Yards 1 094 Kilometers ote neice 0 621 Square Centimeters Square Inches 0 155 Square Square 10 764 Square Square Yards 1 196 Square Kilometers Square Miles 0 386 Square Hectometers ACTOS 03 2 471 Cubic Meters Cubic amp 35 315 Cubic Meters Cubic Yards 1 308 Milliliters Fluid Ounces 0 034 Liters use cc ir ert 2 113 Liters emis
7. HP 8555A 8552 140 Digital Voltmeter HP 3480B 3484A q 9 VOLT IF OFFSET SUPPLY If 39 volts is not being supplied to Predriver A1U2 Set switch to TEST posi tion and check for a voltage level of 9 volts 40 3 V at Assembly test point K junction of R2 and VR1 If voltage is incorrect check R2 and VRI If voltage is 49 volts check switch A3S1 and circuit wiring between 49 volt source and Predriver A1U 2 LJ YIG DRIVER Set Analyzer controls as follows BAND an ek sexos n IF 550 GHz FREQUENCY 4 5GHz SCAN WIDTH ZERO SCAN TIME 10 MILLISECONDS SCAN MODE INT SCAN TRIGGER LINE If Preselector is inoperative and driver section is suspected check fuse A3F 1 If open first check fuse F2 on Power Supply Assembly A2 If A2F2 is open there is no 23 volts bias on A3U1 turning on the YIG Driver transistors ex cessively resulting in burn out of A3F1 If A2F2 is not open try another A3F 1 If the fuse burns out again check transistors Q2 and Q4 and op erational amplifier troubleshooting If fuse A3 F1 is good with a digital volt meter test for approximately 37 volts at A3TPF This voltage is unregulated and will vary according to line voltage input and YIG frequency Set analyzer to TM 11 6625 2781 14 6 Mode18445B BAND n 4 and tune FREQUENCY control to 18 GHz The voltage level at test point F is unregulated but should
8. oe e 3 GHz BANDWIDTH l ana cin Be ae Pe RES SAGA NR VI PES 300kHz SCAN WIDTH PER 10 MHz INPUT 10dB BASE LINE CLIPPER esto dee Puan dx es 12 o dock SCAN TIME PERDIVISION 10 MILLISECONDS LOG REF EEVEL ub REA ER esu ERR ee is 0 dBm EOG EINEAR 2 3 2 ew ERIS ERAI ERAI RE FG RESI Mee E 10dB LOG VIDEQ FI TER nm IER erem ede OR RPM RR pene eds 10kHz SIGNAL GENERATOR FREQUENCY cote pu ER MU WR Ree quts 3GHz ATTENUATION vince ERR Ed PERDU Mb 0dBm ALC CAL OUTPUT cux xk RR R3 awka qupuy w sus 0 dBm on meter 2 Adjust Signal Generator frequency to center signal in Preselector passband indicated by maximum signal level displayed on CRT 3 Adjust Spectrum Analyzer FREQUENCY control to center signal on CRT display 4 Record Signal Generator frequency 5 Adjust Spectrum Analyzer LOG REF LEVEL Vernier control to set signal peak at LOG REFlineofCRT 6 Remove RF interconnect cable from preselector out put to Spectrum Analyzer input and connect Signal Generator to Spectrum Analyzer Input DO NOT CHANGE amplitude controls on Spectrum Analyzer or Signal Generator 7 Tune Generator to a frequency 1 GHz above that recorded instep 4 above Record frequency 8 Tune Spectrum Analyzer to frequency of Signal Generator 9 Ce
9. I I x m 2 T REFERENCE DESIGNATIONS WITHIN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER e g OF ASSEMBLY AT IS DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN SERIAL PREFIX 1404A K6 K3 4 6 9 11 FROM Q6 Q7 8 R32 33 38741 NOTES l SEESCHEMATIC DIAGRAM NOTES TABLE 8 3 2 SEE SERVICE SHEET 2 FOR MATING DETAILS TO INTERCONNECT BOARD POWER GROUND SIGNAL GROUND 3 A1 Figure 8 15 DPM rredriver Schematic Diagram 8 19 SERVICE SHEET 4 Service Sheet 4 contains the schematic diagram of Assembly A3 YIG Driver circuits and controls required to feed the necessary current values to the YIG filter to tune it from 1 8 to 18 GHz On this assembly are the 49 volt IF Offset Supply used on the Predriver n Amplifiers the YIG driver circuits con sisting of a Summing Amplifier and a Driver amplifier a regulated 28 volt supply for YIGs requiring internal heaters and the Automatic Switching Con trol circuit shown on Service Sheet 5 PRINCIPLES OF OPERATION Q 9 VCLT IF OFFSET SUPPLY Resistor A3R2 and the 9 volt breakdown diode VR1 form a simple regulated 9 volt power supply The 9 volt source is utilized by the n Amplifier A1U2 to provide an IF frequency offset Switch S1 is provided for test and adjustment purposes LJ YIG DRIVER The YIG Driver circuit
10. 5 7 Related Adjustments a 2 7 5 9 5 1 15 9 Location of Adjustments 15 11 Power Supplies Adjustment Pol IG or DPM Pre Driver Adjustment 2 1 5 13 YIG Driver Adjustment Digital Panel Meter Adjustment 59 5 14 Option 003 E23 Loss 1 s a eplacemen VI D Lh iL ID 2 3 E23 Dal 2 4 Led VIT MANUAL CHANGES 7 1 Introduction 3 1 7 5 Manual Change instructions 3 1 L3 1 VIII SERVICE l Introduction BA Assembly Service Sheets 13 2 8 5 Principles of Operation 3 2 8 7 Troubleshooting E 3 3 veg Recommended Test Equipment T 3 3 EIL Repair L 3 3 Rigid Cables Cleaning Switches 33 eneral Service Hints L 3 3 Etched Circuit Boards L33 8 19 Component Replacement 1 I 1 1 1 I gq I1 I1 I1 I1 N 1 1 1 NJ t t2 19 t gt N 9 e 1291196 1l I 1Ii 1 i Golfa oe o 0 4 1 5 1 IN TM 11 6625 2781 14 6 Model 8445B CONTENTS Cont d Section Page Section Page 8 21 Beneral Service Information 8 5 APPENDICES Transistors and Diodes 845 Operational Amplifiers 8 5 Delete lectrical Maintenance 8 6 B Service Note No 8555 1 echanical Maintenance Preselector DPM Modification C References s Le i i hiaintena
11. Indicates 550 GHz IF 2 05 GHz IF used on other bands 3 16 OPERATOR S CHECKS 3 17 Upon receipt of the instrument or whenever the Preselector is to be used with a different analyzer perform the Operator s Checks listed in and 3 5 These procedures correct for minor tracking differences between Preselector and Spectrum Analyzer 3 18 OPERATING INSTRUCTIONS 3 19 General operating instructions are con tained in Figure 3 3 These instructions will familiarize the operator with basic operating func tions of the Preselector with the Spectrum Analyzer Additional operating techniques and information are contained in Figures 3 4 and 3 5 3 20 OPERATOR S MAINTENANCE 3 21 Operator s Maintenance involves changing or replacing fuses deaning the air filter and replac ing a defective LINE switch lamp Removing the air filter requires use of a Pozidriv screwdriver all other operations do not require tools 3 22 Fuses 3 23 The primary power fuse is found within the A6 Power Module assembly on the rear panel of the 8445B A fuse change may be necessary when the instrument is moved to a location with a different ac line voltage or when the fuse has burned out Steps one and three of Figure 2 1 show how the fuse is changed or replaced Power Module fuse A6F 1 as well as internal A2 and A3 assembly fuse informa tion is found in Section VI 3 24 Air Filter 3 25 The air filter should be removed and cleaned
12. Es 60 0625 50 ons DIODES DIODE SYMBOL ANODE 9 CATHODE WIDE STRIPE A N CONICAL CATHODE CATHODE CATHODE i CATHODE CATHOD 11 6625 2781 14 6 BI POLAR TRANSISTORS BLACK EPOXY PLASTIC TRANSISTORS EBC METAL CASE TRANSISTORS DUAL Figure 8 2 Examples of Diode and Transistor Marking Methods 8 7 TM 11 6625 2781 14 6 Model 8445B OPERATIONAL AMPLIFIER OUTPUT GAIN 1 OUTPUT V GAIN 1 RI R2 INPUT IMPEDANCE VERY HIGH OUTPUT IMPEDANCE VERY LOW OUTPUT GAIN RI R2 INPUT IMPEDANCE R2 OUTPUT IMPEDANCE VERY LOW IF A IS LARGE Vi Vor V 0 RD R1 Vg Vil 1 Vo7 V 1 63 IFV5 0 THEN 3 1FVy 0 THEN Figure 8 3 Operational Amplifier Equivalent Circuit AUTOMATIC PRESELECTOR SYSTEMS 1 STANDARD PRESELECTOR MODELS The shaded blocks in Figure 8 5 a simp lified block diagram of a Standard Model 8445B Automatic Preselector To use the 8445B YIG filter as a stand alone 1 8 to 18 GHz narrow band pass filter an external tuning voltage of 1 8 to 18 V can be applied to the rear panel BNC connector J 4 Figure 8 4 marked REMOTE The center fre 8 8 quency of the nominally 30 MHz wide filter will follow the remote tuning voltage according to a 1 GHzN relationship The tuned resonant effect of the YIG filter is controlled by the value of
13. 6 Connect the multifunction digital voltmeter between A1TP3 and 2 If the value is not 7 500 Vdc 30 003 Vdc the trouble is due to either a misadjusted DPM Driver or a component failure within the DPM portion of the Al assembly See Service Sheets 2 and 3 for adjustments 7 Connect the multifunction digital voltmeter as in step 3 Set the 8555A to BAND 4 and FRE QUENCY to 18 450 GHz Adjust the 8555A FREQUENCY control for a reading of 18 000 Vdc 30 001 Vdc on the multifunction digital voltmeter equivalent to a frequency display of 18 450 GHz 5 9 TM 11 6625 2781 14 6 Model 8445 ADJUSTMENTS 5 14 DIGITAL PANEL METER ADJUSTMENT Option 003 Cont d 8 Ifthe DPM is not reading 18450 5 counts adjust the control on the rear panel surface of the DPM to this value 9 Connect the multifunction digital voltmeter between AITP3 and A3TP2 If the voltage is not 15 000 Vdc 006 the trouble is within the DPM Predriver section of the Alassembly See Service Sheets 2 and 3 for adjustments 5 15 INSERTION LOSS CHART FOR REPLACEMENT YIG DESCRIPTION After a replacement YIG filter is installed in a Preselector a corrected Insertion Loss Chart should be developed for the new YIG filter Use the following procedure 1 Set up the YIG FILTER INSERTION LOSS TEST for a frequency of 4 GHz as described paragraph 4 19 Record the loss in dB in the proper blank below 2 Repeat the same test inse
14. 1 057 T p s Gall ns i 2a ere prete 0 264 Ims Rape aes A Ounces eve ee ews 0 035 ograms Pounds Sea ees 2 205 Metric Short Tons 1 102 Pounds Feet 0 738 Pounds per Square Inch 0 145 Q ometers per Liter Miles per Gallon 2 354 meters per Hour Miles per Hour 0 621 PIN 035504 000 This fine document Was brought to you by me Liberated Manuals free army and government manuals Why do I do it I am tired of sleazy CD ROM sellers who take publicly available information slap watermarks and other junk on it and sell it Those masters of search engine manipulation make sure that their sites that sell free information come up first in search engines They did not create it They did not even scan it Why should they get your money Why are not letting you give those free manuals to your friends I am setting this document FREE This document was made by the US Government and is NOT protected by Copyright Feel free to share republish sell and so on I am not asking you for donations fees or handouts If you can please provide a link to liberatedmanuals com so that free manuals come up first in search engines
15. DIGITAL VOLTMETER Figure 5 3 YIG Driver Adjustment Test Setup EQUIPMENT Sweep Oscillator 2 18 2 HP 8620A 86290A Swept Amplitude Analyzer 2 18 GHz HP 8755A 180D Dc Power Supply ssepe eere e Dat ace acc cet a e eR RC HP 6205B Frequency Meter HP 536A Frequency amp HP 537A Frequency Meter HP P532A Digital Voltmeter with 3484A Multifunction Unit HP 3480B Detector 2 18 GHZ HP 11664A Modulator 2 18 GHZ 222525951005 11665 Coaxial Attenuator 6 dB HP 8491B Option 006 Coaxial Attenuator 10 8491B Option 010 1 Connect test setup as shown in Figure 5 3 Apply power and allow at least 30 minutes for equipment to stabilize NOTE Perform the Power Supply and Pre Driver Adjustments prior to performing the YIG Driver Adjustments 2 Se the Preselector for remote operation and center the front panel FREQ OFFSET control R1 5 7 TM 11 6625 2781 14 6 ADJ USTMENTS 5 13 YIG DRIVER ADJUSTMENT Cont d 10 1 12 13 14 15 16 Center the panel TRACKING potentiometer R2 Adjust power supply for 41 951 Vdc 1 mVdc at A3
16. b Column 2 Component Assembly Column 2 con tains the noun names of components assemblies sub assemblies and modules for which maintenance is authorized c Column 3 Maintenance Functions Column 3 lists the functions to be performed on the item listed in column 2 When items are listed without maintenance functions it is solely for purpose of hav ing the group numbers in the MAC and RPSTL coin cide d Column 4 Maintenance Cagegory Column 4 D 1 TM 11 6625 2781 14 6 specifies by the listing of a worktime figure in the appropriate subcolumn s the lowest level of maintenance authorized to perform the function listed in column 3 This figure represents the active time required to perform that maintenance function at the indicated category of maintenance If the number of complexity of the tasks within the listed maintenance function vary at different maintenance categories appropriate worktime figures will be shown for each category The number of task hours specivied by the worktime figure represents the average time required to restore an item assembly subassembly component module end item or system to a serviceable condition under typical field operating conditions This time includes preparation time troubleshooting time and quality assurance quality control time in addition to the time required to perform the specific tasks identified for the maintenance functions authorized in the main
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18. Service Sheet 2 includes the schematic diagram the theory of operation and basic troubleshooting procedures for the Pre driver Assembly A1 used in all 8445B Automatic Preselectors The Pre driver converts Sweep Tune voltage from the 8555A to a voltage that is proportional to the frequency to which the RF Section is tuned PRINCIPLES OF OPERATION Ell HARMONIC NUMBER AMPLIFIER The Harmonic Number Amplifier A1U1 multiples the Sweep Tune voltage from the RF Section by a factor of O 4n where n is the BAND number selected on the RF Section panel Table 8 4 The Sweep Tune voltage is prop ortional to the 1st YIG tuned oscillator voltage in the 8555A RF Section This voltage varies linearly from 5 000 5 mV with the ist LO at 2 05 GHz to 10 000 Vdc 5 mV with the 1st LO at 4 1 GHz Precision resistors in the Harmonic Number Amplifier circuit are switched by relays to set the gain of the circuit relative to the harmonic mixing number of the 8555A band that is selected N or AMPLIFIER A 9 Vdc reference voltage from the YIG Driver assembly is applied to the input of the n Amplifier The function of this circuit is controlled by relays K7 K8 to provide either 9 Vdc output level for the plus mixing bands of the 8555A or 9 Vdc for the minus mixing bands Relays K7 and 8 are controlled by Band Code bit E from the RF Section F 550 GHz 2 05 GHz NETWORK When bands are change
19. h Replace The act of substituting a serviceable like type part subassembly or module component or assembly for an unserviceable counterpart i Repair The application of maintenance services inspect test service adjust align calibrate replace or other maintenance actions welding grinding riveting straightening facing remachining or resur facing to restore serviceability to an item by correc ting specific damage fault malfunction or failure in a part subassembly module component or assembly end item or system j Overhaul That maintenance effort service ac tion necessary to restore an item to a completely ser viceable operational condition as prescribed by maintenance standards 1 DMWR in appropriate technical publications Overhaul does not normally return an item to like new condition k Rebuild Consists of those services actions necessary for the restoration of unserviceable equip ment to a like new condition in accordance with original manufacturing standards Rebuild is the highest degree of materiel maintenance applied to Army equipment The rebuild operation includes the act of returning to zero those age measurements hours miles etc considered in classifying Army equipments components D 3 Column Entries a Column 1 Group Number Column 1 lists group numbers the purpose of which is to identify com ponents assemblies subassemblies and modules with the next higher assembly
20. 1 1 8445B Specifications Typical Operating Characteristics 3 Supplied RF Interconnect Cable Information Test Equipment and Accessories Model 8445B Mating Connectors 2 2 Modification of Display Sections for Preselector Compatibility 8555A Frequency Ranges and Recommended Mixing Modes Performance Test Record TABLES Page Table 1 2 3 1 Adjustable Controls and Factory Selected Component 5 2 Insertion Loss Table 2 3 Serial Number Change History Foldouts Assemblies Photographs 2 4 Cross referenced 8 2 Schematic Diagram Notes 3 3 18 3 Etched Circuit Soldering Equipment 4 12 Ez Relay Operations by Band Code Bits Dy 1 oo 09 NIA Joo TM 11 6625 2781 14 6 SECTION 0 INTRODUCTION 0 1 Scope This manual contains instructions for the operation organizational maintenance and general support maintenance of Filter Variable F 1414 U hereinafter referred to as Hewlett Packard Model HP 8445B Automatic Preselector NOTES ontains a list of applicable references Appendix D contains the maintenance allocation chart MAC No direct support maintenance is authoriz ed for this equipment 0 2 Indexes of Publications a DA Pam 310 4 Refer to latest issue of DA Pam 310 4 to determine whether there are new editions changes or additional publications pertaining to the equipment b DA Pam 310 7
21. Deleted d Recommended Test equipment m ISTALLATION Introduction 2 3 Initial Inspection 2 5 Preparation for Use 2 6 Power Requirements n Line Voltage and Fuse zi Power Cable Mating Connectors Operating Environment Installation Instructions Bench Operation Rack Mounting 2 23 Modifications Required Display Sections 2 26 8555A RF Section 2 28 Storage and Shipment Environment 2 31 Packaging OPERATION 3 1 lIntroduction 3 3 Spectrum Analyzer 3 8 Recommended Mixing Modes 3 10 Preselector Tracking 3 12 Preselector Bandwidth 3 14 Panel Features 3 16 Dperators Checks 3 18 Operating Instructions 3 20 JOperators Maintenance x2 Fuses 324 Air Filter an 3 28 Lamp Replacement 11 6625 2781 14 6 CONTENTS Page Section PERFORMANCE TESTS L 1 1 41 Introduction el 14 4 West Record L1 1 26 Jhon Panel Checks L1 4 8 Preset Adjustments L1 1 4 10 Herformance Tests nu L1 reviated Performance Test Abb d Perf T 1 3 4 17 Dut of Band Rejection Test L 1 4 ie Low Pass Filter Insertion Loss Test Omit L 1 4 or Instruments wit tion 1 4 for I h Op 004 L 1 4 4 19 lYIG Filter Insertion Loss Test 155 4 20 limiting Level Test L 1 5 19 ADJUSTMENTS 5 1 Introduction 1 6 5 3 Equipment Regii M 5 5 Factory Selected Components
22. HP Model 34740A manual are shipped with the instrument 1 26 This manual provides necessary references to either the supplement or the A7 DPM Assembly 34740A manual The supplement includes partial schematics tables and explanations of interconnec tions and or modifications made to the Digital Panel Meter which make it compatible to the 8445B 1 27 DESCRIPTION 1 28 The Model 8445B Automatic Tracking Pre selector is designed to complement the Model 8555A Spectrum Analyzer RF Section The Standard Pre selector covers the frequency range of dc to 18 GHz When used with the 8555A Spectrum Analyzer the Preselector functions to reduce or eliminate signal intermodulation in addition to multiple and spuri ous responses The Standard Preselector has a fixed frequency low pass filter for the dc to 1 8 GHz fre quency range and a voltage tuned filter using a YIG yttrium iron garnet crystal as a resonant tun ing circuit in the RF signal path for the frequency range of 1 8 to 18 GHz When used with the 8555A 8552 140 Spectrum Analyzer system the YIG filter is a swept selective filter that tracks the frequency of the analyzer as the analyzer sweeps across its selected range The YIG filter is electroni cally tuned by sweep voltage and band code signals from the analyzer In addition to its primary func tion as a Preselector the YIG filter may be used as a manually or electronically tuned bandpass filter 1 4 Model 844513 Th
23. Position and signals should be approximately 0 1 volt provided the Analyzer is on and the interconnect cable is attached to the Preselector Otherwise Q 1 is non conducting and approximately 38 volts should appear across it PIO AS 6625 2781 14 Model 8445B P O OPTION 002 A5 INTERCONNECT BOARD P O A2 POWER SUPPLY ASSY 08445 60114 IM CPO asnu E meu W INTERCONNECT BOARD DELETE FOR OPTION 004 56 LIRE UN uinci rut sles PE E Pr RE RM P O m OAXIAL SWITCH DRIVER Os r 2 R2 ITCH DRI R24 Be lt 9 10K 33 3 2 er rama 40V l ms gy j ad E z ve T ne N esu I tu REMOTE S A P I W Ww T 9 lt 4 LLL IL J E i R17 R19 S RS ses 51 1K w AN ONY BAND CODE D CR3 CRS RD 1 BAND CODE a _ cri 74 i a Wa 7 1854 002 5L 1K I BAND CODE E CR4 I I 1 12 Q8 1853 0012 TI XA2 3 PREFIX BAND CODE CR2 19 ANS q 1854 007 R14 N 1853 0012 1000 th ER YIG PRE DRIVER ASSY Al fu W PRE DRIVER big OUTPUT 2 W W P O OPTION 002 MANUAL CONTROL BUFFER AMPL 4 a L PEON Me sss a B
24. Turn 8555A 10 1 5 GHz Does signal appear at center of CRT YES Check pilot lamp and line fuse Replace as necessary Turn on power Pilot lamp lights indicating fuse is OK Refer to related Service Sheets for troubleshooting For 9 and 28V supplies 554 For 35 19 5 and 23V supplies SSE NO Disconnect from line Remove all 3 assemblies Check power transformer power module and interconnect ing wiring for sharts or opens Does fuse hold now YES Replace assemblies one at a time until pilot goes out See Troubieshooing Procedure for faulty assembly 1 see 552 553 003 2 see 555 and 6 see 584 Does signat appear if 2nd LO QUIPUT is fed to 8555 input Cable 8555A faulty YES Check resistance across coaxial switch coils in parallel If 40082 replace one switch If intimite ohms replace tobe 2000 hath switches YES Does coaxial switch in 84458 click when switching ta Refer to 555 and troubleshoot coaxial switch driver n 1 1F 550 GHz fromn 1 circuits YES With ohmmeter check rigid cables LP filter and relay contacts for opens or shurts Replace faulty compo nent Replace transformer YIG FILTER CHECK Shift to BAND n 1 IF 2 05 GHz Turn to 4th harmonic fi GHz Does signal show at center of CRT when FREQ OFFSET is adjusted YES Disconnect the Type N BNC 10 dB pad cable from 8445B and connect to 8555 INPUT Does signal d
25. l E ON DISPLAY SECTION n P O 935 OLFREQUENCY FREQUENCY Xa Sg 4 TUNE BUFFER SWEEP TUNE Ul 3 7 1826 0013 Figure B 3 Partial Schematic of Modified A4 Assembly B 2 TM 11 6625 2781 14 6 APPENDIX C REFERENC ES DA Pam 310 4 Index of Technical Publications Technical Manuals Technical Bulletins Supply Manuals Types 7 8 and 9 Supply Bulletins and Lubrication Orders DA Pam 310 7 US Army Equipment Index of Modification Work Orders TM 38 750 The Army Maintenance Management System TAMMS 740 90 1 Administrative Storage of Equipment TM 750 244 2 Procedures for Destruction of Electronics Materiel to Prevent Enemy Use Elec tronics Command TM 11 6625 2781 24 6 Organizational Direct Support and General Support Maintenance Repair Parts and Special Tool List Including Depot Maintenance Repair Parts and Special Tools for Filter Variable F 1414 U HP Model 8445B NSN 6625 00 253 4833 TM 11 6625 2781 14 6 APPENDIX D MAINTENANCE ALLOCATION Section 1 INTRODUCTION D 1 General This appendix provides a summary of the maintenance operations for 1414 U It authorizes categories of maintenance for specific maintenance functions on repairable items and components and the tools and equipment required to perform each function This appendix may be used as an aid in planning maintenance operations D 2 Maintenance Function Maintenance functions will be limited to and
26. tain required operating temperatures within the in strument The air intake and filter are located on the rear of the instrument warm air is exhausted through the side panel perforations When operat ing the instrument choose a location which provides at least three inches of clearance around the rear and sides 2 17 Installation Instructions 2 18 When used with the Spectrum Analyzer the Preselector should be both mechanically and elec trically connected to the Spectrum Analyzer The preferred mounting configuration is with the Pre selector mounted on top of and secured to the Spec trum Analyzer A joining bracket kit is supplied to secure the Preselector to the analyzer A rigid coax ial cable for the preferred mounting configuration is supplied to connect the OUTPUT on the Preselec tor to the INPUT connector of the Spectrum Analyzer F or mounting installations other than the preferred configuration refer to Eigure 1 3 for cable information 2 19 Bench Operation 2 20 The instrument cabinet has plastic feet and a foldaway tilt stand for convenience in bench opera tion The tilt stand raises the front of the instrument for easier viewing of the control panel and the plas tic feet are shaped to make full width modular in struments self aligning when stacked 2 21 Rack Mounting 2 22 This instrument is supplied with a rack mounting kit This rack mounting kit contains all the necessary hardware and installation ins
27. 30 MHz From 7th graticule line from bottom of CRT to 5th graticule line represents approximately 3 dB Low pass filter insertion loss should be 1 dB Remove rigid coaxial cable connecting Preselector OUTPUT to Analyzer INPUT Set Analyzer INPUT ATTENUATION to 40 dB Set Analyzer LOG LINEAR control to LOG Rotate LOG REF LEVEL control to 10 dBm Set SCAN WIDTH PER DIVISION to 10 MHz and set FREQUENCY control to position cursor at 1 5 GHz on frequency scale With INPUT ATTENUATION at 40 dB connect Analyzer SECOND LO OUTPUT to INPUT Center 1 5 GHz LO signal on CRT display Reduce SCAN WIDTH PER DIVISION to 0 2 MHz keeping signal centered on CRT with FREQUENCY control Rotate LOG REF LEVEL control fully counter clockwise Set LOG LINEAR switch to LINEAR and adjust LINEAR SENSITIVITY controls for a 7 1 division display of the 1 5 GHz signal Figure 3 4 Low Pass Filter Operation 10 MHz to 1 8 GHz 2 of 3 11 6625 2781 14 6 Model 8445B OPERATOR S CHECKS USING LOW PASS FILTER Disconnect cable at Analyzer INPUT and couple to INPUT connector on Preselector Connect rigid coaxial cable between Preselector OUTPUT and Analyzer INPUT Note and record low pass filter insertion loss at 1 5 GHz From 7th graticule line from bottom of CRT to 5th graticule line represents approximately 3 dB 1 5 GHz low pass filter insertion loss 2 5 dB Set LOG LINEAR switch to LOG Set LOG REF LEVE
28. 35 V at 0 GHz 28 V at 18 GHz White wire 28 V YIG heater supply The Troubleshooting Flow Diagram Figure 8 7 represents a more detailed troubleshooting procedure which may be followed Equipment needed 8 14 Multi Function Meter HP 427A Clip on HP 428B Model 8445B 8655 Wl 20V OR 12V LEVELS P O OPTION 002 MANUAL CONTROLS HARMONIC NUMBER S 1 005 GHV AMPL AUS BAND CODE DECODER CIRCUITS LOW PASS net i AMPLIFIER MANUAL AUG Ed ee fee ee yet DELETE FOR OPTION 004 0 18 GHz 13 P O A2 POWER SUPPLY ASSY 1 025 AN O OFFSET IRACKING q A POWER SUPPLY 557 PIO M YIG ASSY TM 11 6625 2781 14 6 RF 5 IGNAL NOTES 20V FROM 85554 FOR REMOTE OPERATION EXCEPT OPTION 002 REMOTE OPERATION WITH OPTION 002 JUMPERS OPEN FOR OPTION 002 INSTRUMENTS ONLY A A 9V FROM COARSE TUNE FOR A 5 A5 15 MOTHER BOARD P O DPM ASSY OPTION Q2 ONLY co 1 005 GHziVI T0 DPM CIRCUITRY amp 615 POWER MODULE NO HEATER USED WITH VARIAN YIG V SEE 8445B OPTION 003 SUPPLEMENT 0 Figure 8 8 Comprehensive Block Diagram Including Options 002 003 8 15 SEHVICE SHEET 2 A1 PHE DRIVER ASSEMBLY
29. 4 Delete terminal strip TB2 as shown in partial schematiq Figure 7 2 CHANGE C Page 5 5 followin Insert the following Paragraph 5 124 REMOTE AMPLIFIER ADJUSTMENT 7 1 11 6625 2781 14 6 Model 8445B 5 12A REMOTE AMPLIFIER ADJUSTMENT REFERENCE Service Sheet 5 DESCRIPTION The remote amplifier A2U3 is adjusted for null common mode and differential mode The adjustments are repeated until settings are found that satisfy null common mode and differential mode requirements DIGITAL MULTIFUNCTION DC POWER VOLTMETER UNIT SUPPLY TO A TP5 TO A2TP4 TO REMOTE SHIELD TO A3TP2 Figure 7 1 Remote Amplifier Adjustment Test Setup P O CHANGE C EQUIPMENT Power Supply 0 4010 00 HP 6205B Coaxial Cable BNC to alligator dips HP 10501A Four foot test leads with alligator dips 2 each Digital Voltmeter with Multifunction Unit HP 3480B 3484A 1 With test setup as indicated in Figure 7 1 apply power to Preselector and allow at least 30 minutes for equipment to stabilize 2 Connect terminal of power supply to A3TP2 3 Connect terminal of power supply to REMOTE connector shield Ground the negative terminal of the power supply with the shorting bar 4 Connect terminal of digital voltmeter to A2TP4 5 Connect terminal of digital voltmeter to A2TP5 6 Set power supply output voltage to zero and connect REMO
30. 5 dB 2 5 dB Repeat steps 2 through 5 using 2050 MHz Insertion loss should be 50 dB gt 50 dB Model 8445B Center 1 8 GHz signal on CRT display with FREQUENCY control Set TUNING STABILIZER to ON and reduce SCAN WIDTH PER DIVISION to 100kHz Center signal on CRT display withFINE TUNE control Adjust Signal Generator CAL OUTPUT 8616A only level for an indicated 20 dBm on CRT display dB dB Model 8445B TM 11 6625 2781 14 6 PERFORMANCE TESTS 4 19 YIG FILTER INSERTION LOSS TEST SPECIFICATION Tracking Filter Insertion Loss 1 8 12 GHz 8 dB 12 18 GHz 10 dB Option 004 only 1 8 12 GHz lt 7 dB 12 18 GHz 8 DESCRIPTION YIG filter insertion loss is measured at fixed frequency points by applying a known signal level tuning the YIG filter passband to the signal and measuring the power out the filter output port Perform the Operator s Check in Figure 3 to performing the test below The operator s Check sets the FREQ OFFSET and TRACKING controls The YIG filter is tuned by applying a voltage to the REMOTE input Voltage to frequency tuning ratio is 1GHz volt The Preselector FREQ OFFSET control is used as a fine tuning control DC POWER SUPPLY SWEEP OSCILLATOR TO REMOTE BNC 1048 f ATTENUATOR 9 SPECTRUM ANALYZER Figure 4 3 Insertion Loss Test Setup 1 8 18 GHz EQUIPMENT Power Meter amp Power
31. 8 20 The following procedures are recommended when component replacement is necessary NOTE Although not recommended when both sides of the circuit board are accessible axial lead components such as resistors and tubular capacitors can be replaced without unsoldering Clip leads near body of defective component remove component and straighten leads left in board Wrap leads of replacement com ponent one turn around original leads Solder wrapped connection and clip off excess lead a Remove defective component from board b If component was unsoldered remove solder from mounting holes with a suction device or a wooden toothpick c Shape leads of replacement component to match mountig hole spacing d Insert component leads into mounting holes and position component as original was positioned Do not force leads into mounting Model 8445B 8 21 GENERAL SERVICE INFORMATION 8 22 Transistors and Diodes 8 23 Transistors and diodes are used throughout the Preselector in circuit configurations such as delay circuits trigger circuits switches oscillators and various types of amplifiers Basic transistor op eration is shown in the following pages 8 24 Transistor In Circuit Testing The com mon causes of transistor failure are internal short circuits and open circuits In transistor circuit test ing the most important consideration is the transis tor base to emitter junction The base emitter junc tion in a tr
32. A71 Te s r W rm Figure 8 12 Top View of 8445B Option 003 With A7 Removed TM ll 6625 2 851 l4 t 5 18 Figure 8 13 OPTION 003 ONLY Al Predriver Assembly of 8445B Option 003 Model 8445B Model 8445B MATES WITH P2 BLUE WHITE WIRE A7R1 10K A7R2 1142 1 BLACK WHITE WIRE Figure 8 14 A7 Display Board See Option 003 Supplement For Details A7 8445B TM 11 6625 2781 14 6 BAND K3 K9 ON ON OFF OFF OFF HARMONIC BAND ON NUMBER CODE on C ON nl 0 ON n 0 ON nl 0 ON 1 0 ON n2 0 ON 2 0 P O 1 DPM PREDRIVER ASSY OPTION 003 ONLY 08445 60102 n3 0 Wasa jua a LENS Sg UE RU RT Y UL GIU eem nene mU Tu PM n 3 0 MM HARMONIC NUMBER AMPLIFIER SUMMING AMPL n4 0 es 4 0 R54 R55 R58 R R65 8000 800 800 52 4 2 L5T0 1V OPR Re RS Q 10K 10K 10K R60 TUNE R62 INPUT 206 TEST 0 9 R45 3L6K 5 6HzB 05 GHz NETWORK R3 R4 51 R61 16 2K 7500 85 CW M 419 5V 19 2 0 9 K3A o I 1 i t 1 80 4 6 Eie TOP VIEW 19 5 l NOTE 2 2050 MHz IF I NJ V REFERENCE a eee R57 R41 SIGNAL GROUND 200 i l POWER GROUND e v x j 19
33. E 5 TM 11 6625 2781 14 6 A3 Figure 8 16A A3 YIG Driver Assembly Change 1 E 6 TM 11 6625 2781 14 6 Figure 8 18A A2 Power Supply Assembly Remote and Manual Control Amplifiers Switching Circuit Change 1 TM 11 6625 2781 14 6 R36 UNDER NEATH Figure 8 20A A2 Power Supply Assembly Supply Voltage Circuits Change 1 By Order of the Secretary of the Army Official J C PENNINGTON Brigadier General United States Army The Adjutant General Distribution Active Army HISA Ft Monmouth 26 USAINSCOM 2 COE 1 TSG 1 USAARENBD 1 DARCOM 1 TRADOC 2 OS Maj Cored 4 TECOM 2 USACC 4 MDW 1 Armies 2 Corps 2 Svc Colleges 1 USASIGS 5 USAADS 2 USAFAS 2 USAIS 2 USAARMS 2 USAES 2 USAICS 3 MAAG 1 ARNG NONE USAR NONE For explanation of abbreviations used see AR 310 50 BERNARD W ROGERS General United States Amy Chief of Staff USARMIS 1 USAERDAA 1 USAERDAW 1 Ft Carson 5 Ft Gillem 10 Ft Gordon 10 Ft Huachuca 10 Ft Richardson CERCOM Oft 2 Army Dep 1 except LBAD 14 SAAD 30 TOAD 14 SHAD 3 USA Dep 1 Sig Sec USA Dep 1 Units org under fol TOE 29 207 2 29 610 2 US GOVERNMENT PRINTING OFFICE 1988 0 201 421 PO 80153 RECOMMENDED CHANGES TO EQUIPMENT TECHNICAL MANUALS SOMETHING WRONG ns ww FROM YOUR UNIT S COMPLETE ADDRESS Commander Stateside Army Depot ATTN
34. OPTION 002 Set MODE switch to MANUAL Set FINE MANUAL Refer to 555 for MANUAL amplifier Circuit TUNE to 0 When COARSE MANUAL TUNE is varied is voltage at AZTPG 0 976 of dial reading in GHz troubleshooting YES Refer to 551 and 556 Check MODE switch wiring from 4110 for opens or shorts Troubleshoot 2 Coaxial Switch Driver Does YIG tuning coil current read 26 mA GH2 when COARSE MANUAL TUNE is tuned YES REMOTE Standard models remove W3 Option 002 Set Mode NO Refer to 555 for REMOTE amplifier circuit Switch to Remote Does voltage at A2 TPA read 0 976 troubleshooting of 0 1 to 18V applied to REMOTE INPUT YES Refer to 551 and 555 Check MODE switch wiring from 2 to for opens or shorts Does YIG tuning coil current read 26 mA GHz when remote power supply is tuned LOW PASS YES FILTER OPTION 002 Refer ta S81 and 555 Check MODE switch wiring between switch and A for opens or shorts Set MODE switch to LOW PASS Tune 8555A ta 1 6 GHz Signal should appear on center CRT YES DIGITAL DISPLAY Set 8555A to 10 GHz OPM should read within 20 MHz of this valve OPTION 003 Refer to 553 for troubleshooting DPM circuits Troubleshooting complete Unit is operating normally Figure 8 7 Troubleshooting Fiow Diagram 8 13 SERVICE SHEET 1 TROUBLESHOOTING General The 8445B Automatic Preselector simplified Comprehensive Block Diagram of Figure 8 8 i
35. Refer to DA Pam 310 7 to determine whether there are modification work orders MWO S pertaining to the equipment 0 3 Forms and Records a Reports of Maintenance of Unsatisfactory Equipment Maintenance forms records and reports which are to be used by maintenance personnel at all levels are listed in and prescribed by TM 38 750 b Report of Packaging and Handling Deficiencies Fill out and forward DD Form 6 Packaging Improve ment Report as prescribed in AR 700 58 NAVSUPINST 4030 29 AFR 71 13 MCO P4030 29A and DLAR 4145 8 c Discrepancy in Shipment Report DISREP SF 361 Fill out and forward Discrepancy in Shipment Report DISREP SF 361 as prescribed in AR 55 38 NAVSUPINST 4610 33 B AFR 75 18 MCO P4610 19C and DLAR 4500 15 0 4 Administrative Storage Before placing the F 1414 U in temporary storage 90 days determine the serviceability of the equip ment by performing the maintenance procedures described in paragraphs 8 32 and 8 34 0 5 Destruction of Army Electronics Materiel Destruction of Army electronics materiel to prevent enemy use shall be in accordance with TM 750 244 2 0 6 Reporting Equipment Improvement Recommendations EIR EIR s will be prepared using Standard Form 368 Quality Deficiency Report Instructions for preparing EIR s are provided in TM 38 750 The Army Maintenance Management System EIR s should be mailed direct to Commander US Army Com munications and Electronics Mate
36. SEE SCHEMATIC DIAGRAM NOTES TABLE 8 3 SERIAL PREFIX 1404A 2 W POWER GROUND 3 NB SIGNAL GROUND A3 A4 Figure 8 16 A3 YIG Driver Assembly Figure 8 17 P O YIG Driver Schematic Diagram 8 21 SERVICE SHEET 5 CONTROL AND SWITCHING CIRCUITS General Service Sheet 5 contains the schematic diagram for the input output Coaxial Switch Driver circuitry the Manual Control Buffer Amplifier the Remote Con trol Buffer Amplifier and the Automatic Switching Control circuitry It also indudes the panel controls of Standard as well as Option 002 instruments COAXIAL SWITCH DRIVER The Coaxial Switch Driver circuitry on Assembly A2 provides a polarized con trol voltage for the two input output coaxial relays to connect either the YIG Filter or the Low Pass Filter to the front panel ports The coaxial relays are the polar latching type When driven in one direction they latch until driven in the other direction The driven direction depends cm the relative voltage levels across the coils Depending on whether the base of A2Q2 is forward biased or not the emitter of A2Q4 will either rise to nearly 40 volts or drop to a low positive potential Transistor A2Q8 acts as an inverter lowering the positive potential of the emitter of A2Q5 when the emitter of A2Q4 rises It raises the positive potential of the A2Q5 emitter when the A2Q4 emitter lowers At any given time the top of the relay coils are either more positive than the bottom or l
37. be approximately 30 volts If there is no change in voltage level between 1 5 and 18 GHz settings check the input levels at pins 2 and 3 of U1 The voltage difference between these pins and ground should not exceed 25 mV The driver stage consisting of U1 Q2 Q3 Q4 and associated components function as a single operational amplifier The normally less than 10 mV difference at the input of U1 is affected by adjusting COARSE FREQ OFFSET resistor R7 Amplifier U1 can be isolated from the driver transistors by first removing fuse F1 and then connecting a jumper from test point to TP3 Repeat voltage measurements at input of U1 If voltage level differs by more than 25 mV try adjusting resistor R7 If R7 has little or no effect replace U1 If U1 appears to be good check for open or shorted transistor s or diode s in the driver amplifier A shorted transistor or diode will normally cause fuse F1 to open Linearity Correction Breakpoints Connect the digital voltmeter to A3TP1 Select BAND n 4 with SCAN WIDTH at ZERO Tune FREQUENCY control from 14 to 15 GHz noting voltage level on digital voltmeter Between 14 and 15 GHz the voltage should begin to increase indicating breakdown of the diode With the digital voltmeter at A3TPH the breakdown should occur between 16 and 17 GHz The procedure for making breakpoint tracking adjustments is outlined if Paragraph 5 10 Q 28 VOLT HEATER SUPPLY When operating with the YIG heater connected the v
38. dc current fed to its tuning coil electromagnet Tuning sensitiv ity is approximately 26 mA GHz In the Standard Model operation is selected automatically if the 8445 is not connected to an 8555A RF Section When operating as a preselector for an 8555A RF Section Spectrum Analyzer the RF OUTPUT of the 8445B is connected to the INPUT of the 8555A by rigid cable W1 Model 8445B The YIG PreDriver uses input voltages from the 8555A Spectrum Analyzer System and produces an output voltage that is proportional to the frequency to which the analyzer is tuned The analyzer pro vides a Sweep Tune voltage that is representative of the frequency of the YIG oscillator in the analyzer This voltage varies linearly from 5 000 volts for a LO frequency of 2 050 GHz to 10 000 volts for a LO frequency of 4 100 GHz The Sweep Tune voltage is applied to a harmonic number amp lifier in the Preselector The gain of the harmonic amplifier is controlled by Band Code signals A and B from the analyzer Band Code bits A and B represent the frequency bands n 1 through n 4 The output from the harmonic number amplifier is a voltage representative of LO harmonic frequency The frequency to voltage ratio is 1 025 GHz Volt The output from the harmonic amplifier is applied to a summing amplifier where it is combined with the IF offset voltage Band Code bit E from the analyzer is applied to the n or mixing offset amplifier in the Presele
39. defined as follows d Inspect To determine the serviceability of an item by comparing its physical mechanical and or electrical characteristics with established standards through examination b Test To verify serviceability and to detect in cipient failure by measuring the mechanical or elec trical characteristics of an item and comparing those characteristics with prescribed standards c Service Operations required periodically to keep an item in proper operating condition i e to clean decontaminate to preserve to drain to paint or to replenish fuel lubricants hydraulic fluids or com pressed air supplies d Adjust To maintain within prescribed limits by bringing into proper or exact position or by set ting the operating characteristics to the specified parameters e Align To adjust specified variable elements of an item to bring about optimum or desired perfor mance f Calibrate To determine and cause corrections to be made or to be adjusted on instruments or test measuring and diagnostic equipments used in preci sion measurement Consists of comparisons of two in struments one of which is a certified standard of known accuracy to detect and adjust any discrepancy in the accuracy of the instrument being compared g Install The act of emplacing seating or fixing into position an item part module component or assembly in a manner to allow the proper func tioning of the equipment or system
40. ensure safe operation and to keep the instrument safe Service and ad justments should be performed only by qualified service personnel 1 16 Adjustment or repair of the opened instru ment with the ac power connected should be avoided as much as possible and when inevitable should be performed only by a skilled person who knows the hazard involved 1 17 Make sure only fuses of the required current rating and type normal blow time delay etc are used for replacement Do not use repaired fuses or short circuit the fuse holders 1 18 Whenever it is likely that the protection has been impaired make the instrument inoperative and secure it against any unintended operation WARNING If this instrument is to be energized through an autotransformer for line voltage variation make sure the common terminal is connected to the earthed pole of the power source BEFORE SWITCHING ON THE INSTRU MENT the protective earth terminals of the instrument must be connected to the protective conductor of the mains power cord The mains plug shall only be inserted in a socket outlet provided with protective earth contct The pro tection must not be negated by using an exten sion cord power cable without a protective grounding conductor Any interruption of the protective grounding conductor inside or outside the instrument or disconnection of the protective earth terminal is likely to make this instrument dangerous Intentiona
41. indicated reference is made to the Service Sheet where isolation to the faulty component is exp lained 8 9 RECOMMENDED TEST EQUIPMENT 8 10 Test equipment and accessories required to maintain the Preselector are listed in Table 1 5 If the equipment listed is not available equipment that meets the required specifications may be sub stituted 8 11 REPAIR 8 12 Rigid Cables 8 13 If necessary to loosen or remove rigid RF cables between filters coaxial switches and panel connectors care must be taken not to alter their shape Bending may affect electrical characteristics of the cables 8 14 Cleaning Switches 8 15 Front panel and board mounted switches may be deaned without removal The deaning agent recommended is isopropyl alcohol HP Part No 8500 0755 Spray the solvent into the switch while sliding the switch back and forth Repeat the procedure several times Continue to slide the switch until the solvent is evaporated 8 1 TM 11 6625 2781 14 6 Model 8445B Table 8 1 Foldouts Assemblies Photographs Cross referenced Foldouts Simplified Block Diagrams Assemblies Involved Al A2 A3 A4 A7 Assembly Photographs SERVICE SHEET 1 Trouleshooting Flow Diagram Comprehensive Block Diagram SERVICE SHEET 2 YIG Predriver SERVICE SHEET 3 Al A2 A3 A4 A7 Al Standard Al Standard A1 Opt 003 A1 Opt 003 SERVICE SHEET 4 YIG Driver A3 A4 A3 SERVICE SHEET
42. track when operating with an 8555A Spectrum Analyzer It indicates signal fre quencies from 0 01 18 GHz and the recommended 8555A frequency bands to be used for them Analyzer responses tracked by the Preselector overlap at the edges of different frequency bands Note the intersection of then 3 tuning curves at 4 1 GHz in Figure 3 1 Signals near the intersection points can appear in the passband of the Preselector from both of these mixing modes 11 6625 2781 14 6 SIGNAL FREQUENCY GHz 4 W S FILTER 3 LOW PASS FILTER LO PAS 0 LOCAL OSCILLATOR LO FREQUENCY Responses tracked by Preselector No scale provided internal mixing on n 5 and n 6 modes Image responses without Preselector Multiple responses without Preselector Figure 3 1 Spectrum Analyzer Tuning Curves and Responses 3 10 PRESELECTOR TRACKING 3 11 The Preselector tracking with the Spectrum Analyzer is governed by the linearity of the 8555A s 3 2 Model 8445B YIG Drive sweep voltage versus the first LO fre quency Preselector tracking in both REMOTE and MANUAL operating modes is affected by the front panel FREQ OFFSET and TRACKING controls Ad justment of these controls changes the accuracy of the 1 V GHz remote tuning and the dial accuracy of the manual controls To adjust FRE Q OFFSET and TRACKING controls for correct REMOTE or MANUAL operation perform the YIG DRIVER ADJ USTMENTS in Section V Jof this man
43. with output polarity controlled by Band Code bit E which alternately switches relays K7 and K8 as bands are progresively selected see Table 4 below If improper n Amplifier action is indicated see Paragraph 8 30 for Operational Amplifier Troubleshooting Procedure TM li 6625 2751 l4 O Model 8445B Table 8 4 Relay Operations by Band Code Bits Analyzer Band Code Harmonic Number closed open closed open closed closed open closed closed closed open open open closed closed closed open Band Code Bits 1 550 GHz 2 05 GHz NETWORK SUMMING AMPLIFIER Set switches A1S1 and A3S1 to TEST position and check A1TP7 for a level of O Vdc 1 mV If test voltages are out of tolerance see Paragraph 5 9 for adjustment procedure Return switches A1S1 and A3S1 to OPR Set analyzer to BAND n 1 550 GHz SCAN WIDTH to ZERO and adjust FREQUENCY dial for a voltage level of 5 000Vdc at A1TP1 Measure voltage at A1TP7 for an indicated level of 1 463 Vdc 2 mV Select BAND n 1 550 GHz and check at A1TP7 for a voltage level of 2 536 Vdc 2 mV Shift to BAND n 2 and check at A1TP7 for a voltage level of 2 000 2 mV Check BAND 2 for 6 000 3 mV at A1TP7 The 550 MHZ and 2 05 GHz IF offset is controlled by Band Code D see Table 8 4 above If improper Summing Amplifier ac
44. 2 05 CoP n 3 TO U3 x PIN7 6 O Y 1 025 GHz V MANUAL TUNE TO PINS FINE XIBAR D DPM DRIVE INPUT OPTION 003 ONLY Plo A YIG DRIVER ASSY PREDRIVER OUTPUT SEE TABLE 873 20V FROM COARSE TUNE CONTROL r 4 eH mec Ee bos eb Y W m RU FOR OPTION 002 e Am P Ae TS N E n 19 5V JUMPER BETWEEN P2P14 AND BNC 4 P2P2 EXCEPT FOR OPTION 002 JUMPER FROM RY3 TO DRIVER EXCEPT FOR OPTION 002 JUMPER INSTALLED EXCEPT E FOR OPTION 002 POWER GROUND A2 SIGNAL GROUND A3 A4 Figure 8 19 Remote and Manual Control Amplifiers Switching Circuit Schematic Diagram i 2008 19 SV FROM REFERENCE DESIGNATIONS WITHIN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER e g R OF ASSEMBLY Al IS AIRI DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN Figure 8 18 A2 Power Supply and Filter Switching Assembly 8 23 SERVICE SHEET e POWER SUPPLIES General Service Sheet G contains the schematic diagram for the auaunregulated 40 volt and the regulated 1 9 5 and 23 volt power supplies It also includes the wiring diagrams for the power transformer interconnections to the power line voltage module and selection card see Figure 2 1 gt Power transformer Ti secondaries provide xz v rms at 1 5 A and 27 7 Vrms at A for associated power supplies THEORY OF OPERATIO
45. 2050 MHz Insertion Loss YIG FILTER INSERTION LOSS Reference Frequency Reference Signal Level Preselector Signal Level Insertion Loss 8 dB Reference Frequency Reference Signal L evel Preselector Signal L evel Insertion Loss LIMITING LEVEL 1 Reference Frequency 7 Reference Level 9 Measurement Level 10 Compression Loss 1 dB Model 8445B TM 11 6625 2781 14 6 SECTION V ADJUSTMENTS 5 1 INTRODUCTION when repairs are required Induded in this section are test setups checks and adjustment procedures 5 2 This section describes adjustments required to return the Preselector to peak operating condition 5 3 EQUIPMENT REQUIRED Table 5 1 Adjustable Controls and Factory Selected Component Control Reference Designation See NOTE Below A1R34 R38 Null Control Nulls A1U1 A1R35 R39 Null Control Nulls A1U2 A1R36 R40 550 MHz IF Offset Adds correct voltage to Summing Amplifier to Offset for 550 MHz IF AIR37 R41 2 05 GHz IF Offset Adds correct voltage to Summing Amplifier to Offset for 2 05 GHz IF A1R42 R46 Null Control Nulls A1U5 A2R5 19 5 Vdc Adjust Sets regulated 19 5 Vdc A3R13 COARSE TRACKING Selected component Typical range value 26 1 ohms Adjusts COARSE TRACKING circuit 15 GHz Breakpoint Corrects for YIG Magnet Adjust saturation 18 GHz Breakpoint Corrects for YIG Magne Adjust Saturation Z Zero Adjust Adjusts DPM to zero volts 0 GHz Negative Adjust Adjusts DPM for 18 v
46. 5 Power Supply and Switching SERVICE SHEET 6 Power Supply and Module Adjustment Controls 8 16 GENERAL SERVICE HINTS 8 17 Etched Circuit Boards 8 18 The etched circuit boards used in Hewlett Packard equipment are the plated through type consisting of metallic conductors bonded to both sides of insulating material The circuit boards can be either a single layer or multi layer board The metallic conductors are extended through the com ponent holes or interconnect holes by a plating pro cess Soldering can be performed on either side of the board with equally good results Table 8 3 lists recommended tools and materials for use in repair ing etched circuit boards Following are recommen dations and precautions pertinent to etched circuit repair work a Avoid unnecessary component substitution it can result in damage to the circuit board and or adjacent components 8 2 A2 A3 A4 A2 A2 A6 A2 A1 Standard A1 Opt 003 A2 A3 b Do not use a high power soldering iron on etched circuit boards Excessive heat may lift a conductor or damage the board C Use a suction device or wooden toothpick to remove solder from component mounting holes CAUTION Do not use a sharp metal object such as an awl or twist drill for this purpose Sharp objects may damage the plated through conductor d After soldering remove excess flux from the soldered areas and apply a protective coating to prevent contaminatio
47. 5 00 913 9781 TOOL NUMBER D 5 11 6625 2781 14 6 SECTION REMARKS REFERENCE CODE REMARKS REPAIR BY REPLACEMENT OF FUSE AND FRONT PANEL LAMP D 6 APP TM 11 6625 2781 14 ENDIX DIFFERENCE DATA SHEETS 6 The following changes must be made to the technical manual as a result of equipment production changes Check the 217 table for the appro priate serial number and enter any listed change s in the manual Serial Prefix or Number 1442A00921 thru 1442A01175 1442A01176 thru 1442 prefix Make Manual Changes x BEER TM 11 6625 2781 14 6 CHANGE 1 Page 8 17 Service Sheet 2 Replace with Figure 8 9A contained in this Manual Changes Supplement Page 8 17 Figure 8 10 Service Sheet 2 Add capacitor Cl 2 2 uF from A1UI pin 4 to signal ground how positive side of capacitor connected to signal ground Add capacitor C2 2 2 uF from A1US pin 7 to signal ground Show positive side of capacitor connected to pin 7 Add capacitor C3 2 2 F from 105 pin 4 to signal ground Show positive side of capacitor connected to signet ground Add capacitor C4 2 2 uF from A1U2 pin 7 to signal ground Show positive side of capacitor connected to pin 7 Page 8 18 Figure 8 13 Service Sheet 3 Replace with Figure 8 13A contained in this Manual Changes Supplement Page 8 21 Figure 8 14 Service Sheet 4 Replace with Figure 8 16A contained i
48. 81 14 6 ADJUSTMENTS 5 12 YIG OR DPM PRE DRIVER ADJUSTMENT Cont d 3 Set Spectrum Analyzer controls as follows ee Spent de Rive dente n 2 SCAN WIDTH ENNIO REDUCE ZERO INPUT ATTENUATION usa um aY u kawan A 10 dB SCAN TIME PER DIVISION i ord ht tate a m 10 MILLISECONDS SCAN MODE Ous RIS p eats eee DO a ga INT SCAN TRIGGER dowd ge cumbia Nand sa tnde E Laeti 10 dB LOG LOG REFERENCE LEVEL lisas ay t e Res 10 dBm NOTE dc voltages are measured with respect to common ground test point A3TP2 4 Set switch 151 and 152 to TEST position 5 Set switch A3S1 to TEST position 6 Se the voltage at the following test points in specified order with the appropriate pot Test Point Limits 0 00 0 20 mV 0 00 0 20 mV 0 00 0 20 mV 0 00 0 20 mV 0 00 0 20 mV 0 00 0 20 mV 7 Set A3S1 to OPR 8 Adjust AIR37 and A1R41 to obtain 42 000 V at AITP7 A1TP8 respectively 9 Spectrum Analyzer to BAND n 2 and verify voltage at 7 and AITP8 Voltage should be 2 000 0002 v 1 998 __ 2 002V 10 Set to BAND n 14 l F 550 GHz Adjust A1R36 and A1R40 to obtain 536 6 mV at AITP7 and AlTP8 respectively B 11 Set to BAND 1 1 550 GHz and verify voltage at AITP7 and A1TP8 Vo
49. 8555A Manual to ensure signal displayed is result of n 2 mixing mode Set SIGNAL IDENTIFIER switch to OFF Adjust Sweep Oscillator POWER LEVEL and or Analyzer LOG REF LEVEL Vernier for a convenient signal level Disconnect 10 dB attenuator from Spectrum Analyzer Connect Power Meter and Power Sensor to 10 dB attenuator and measure power level Record signal level _ dBm Connect Sweep Oscillator RF output with 10 dB attenuator to Preselector INPUT Install rigid coaxial cable W1 between Preselector OUTPUT and Spectrum Analyzer INPUT Adjust Power Supply Vernier voltage control for maximum signal level indication on CRT display NOTE Tuning rate is critical The frequency tuning of the Preselector passband is changed at a rate of 1 MHz mV Adjust FREQ OFFSET to maximize signal level on CRT display Record signal level dBm Subtract level recorded in step 9 dB Record insertion loss at 4 GHz Insertion loss should be 8 dB at 4 GHz _ dB Repeat the above procedure at selected frequency points to 18 GHz See specifications for acceptable limits of insertion loss 4 20 LIMITING LEVEL TEST SPECIFICATION gt 45 dBm for lt 1 dB signal compression 4 9 TM 11 6625 2781 14 6 Model 8445B PERFORMANCE TESTS 4 20 LIMITING LEVEL TEST Cont d DESCRIPTION YIG filter compression is checked at the low frequency end of the operating range point of maximum filter compression Compression is measured b
50. AMSTA US THEN JOT DOWN THE DOPE ABOUT IT ON THIS FORM TEAR IT OUT FOLD IT AND DROP IT IN THE Stateside N J 07705 pave 30 July 1975 PUBLICATION NUMBER DATE TITLE TM 31580 340 12 23 Jan 74 Radar Set AN Z8 amp 76 BE EXACT PIN POINT WHERE IT IS IN THIS SPACE TELL WHAT 15 WRONG 5 AND WHAT SHOULD BE DONE ABOUT IT FIGURE TABL NO NO lt Recommend that the installation antenna alignment procedure be changed throu Specify a 29 IFF antenna lag rather than 1 REASON Experience nas shown that with only a 1 lag the antenna servo sy is too sensitive to wind gusting in excess o knots and has a tendency to rapidly accelerate elerate as it hunts causing strain to the drive tr in Hunting is minimized by adjusting the lag to 29 without degradation of operatio 3 1 Item 5 Fune column Change 2 db to REASON ustment procedure for the TRANS POWER FAULT indica calls for a 3 db 500 watts adjust ment to light the TRANS POWER FAULT indicator TEAR ALONG DOTTED LINE Ad step f l to read Replace cover plate removed i l above REAS To replace the cover plate FO3 Zone 3 On J1 2 change 24 VDC to 5 REASON This is the output line of the 5 VDC power supply 2h VDC is the input voltage TYPED NAME GRADE OR TITLE AND TELEPHONE NUMB
51. BANDs n 1 IF 2 550 GHz through 4 The voltage level should be approximately 19 5 volts on all bands except 1 IF 2 05 GHz On this band it should be approximately O volts Check voltage levels at test points B C D and E for BAND n 1 IF 22 05 GHz and BAND n 1 F 550 MHz Use 202 A2Q3 and 204 transistor cases for test points B Canal D Compare levels with the typical values shown below Voltage Level Test Point BAND BAND n 1 IF 2 05 GHz n 1 IF 550 GHz 40 v 2 7 V 40 v 43 5 v B MANUAL CONTROL BUFFER AMPLIFIER Applies to instruments with option 002 only Check operational amplifier A2U2 for unity dc gain and inversion of input voltage Compare input voltage at A2U2 pin 2 with output at A2TP6 For operational amplifier troubleshooting see Paragraph 8 30 REMOTE CONTROL BUFFER AMPLIFIER Connect a 10 000 volt power supply to REMOTE input on rear panel of Preselector with positive to center conductor and negative to shield Check voltage output from 203 as 9 77 volts 10 V divided by 1 025 If incorrect remove 10 volt power supply and check resistors and capacitors to input of A2U3 For operational amplifier troubleshooting se Paragraph 8 30 AUTOMATIC SWITCHING CONTROL The Automatic Switching Control transistor A3Q1 is held in saturation by either a 20 or a 19 5 volt dc fed to it through A3R22 In option 002 instruments A3Q 1 is held in saturation regardless of Mode Switch
52. Display Section and TUNING CONTROL SPECTRUM ANALYZER input on Preselector Connect Preselector and Spectrum Analyzer to line voltage source and apply power Perform Spectrum Analyzer Operational Adjustments in Section III gf Spectrum Analyzer RF Section 8555A Operating and Service Manual Connect the rigid W1 coaxial cable between Preselector OUTPUT and RF Section INPUT Set LOG REF LEVEL to 0 dBm Set SCAN WIDTH PER DIVISION to 10 MHz Connect a 30 dBm 2 0 GHz signal to INPUT connector on Prelector Select 1 550 MHz Frequency BAND and tune Analyzer FREQUENCY control to center the 2 0 GHz signal on CRT display Reduce SCAN WIDTH PER DIVISION to 0 5 MHz keeping signal centered on display with FREQUENCY control Reduce SCAN WIDTH PER DIVISION to 100 kHz center signal on display with FINE TUNE control Set LOG LINEAR switch to LINEAR and LINEAR SENSITIVITY control to 1 mV DIV Adjust Preselector FREQ OFFSET control to center YIG filter passband on the 2 GHz signal and maximize signal on CRT display Set Analyzer LOG LINEAR control to 10 dB LOG Rotate LOG REF LEVEL control to 30 dBm Adjust LOG REF LEVEL Vernier control to position signal peak on LOG REF LEVEL graticule line Connec a 30 dBm 8 0 GHz signal to INPUT Connector on Preselector Select n 2 1F 2050 MHz Frequency BAND on Analyzer set SCAN WIDTH PER DIVI SION to 10 MHz and tune FREQUENCY control to center the 8 0 GHz signal on CRT
53. E SHEET 3 DPM PREDRIVER OPTION 003 ONLY The additional circuits of the Digital Panel Meter Predriver part of the Option 003 Assembly A1 shown on Service Sheet 3 are similar to the circuits on the Standard Model Assembly A1 shown on Service Sheet 2 The longer Option 003 Predriver Assem bly 1 board consists of the DPM Predriver circuits mounted adjacent to the mother board A5 with the YIG Predriver circuits behind the front panel and directly below the DPM Assembly PRINCIPLES OF OPERATION BB except for the input voltage level to the Al Option 003 Assembly the Harmonic Number Amplifier the n Amplifier the IF 550 GHz 2 05 GHz Network and the Summing Amplifier of the D2M Predriver operate the same as the YIG Predriver circuits of Service Sheet 2 The 7 5 to 15 voltages for the DPM Predriver originate in the Tune Buffer Amplifier of the 8555A BH Band Code Logic C feeds a 0 or 12 V bit to Q7 on all bands involving frequencies of OQ to 18 GHz allowing Os ton energizes K 11 With 11 ecantarte closed the 152 VOR DIIS m an fee ACLARA CES l 5 1 to 18 00 Vdc output for 0 18 45 GHz from the DPM Pre driver is fed to the DPM giving a voltage display of the frequency which the 8555A RF Section is receiving TROUBLESHOOTING PROCEDURE The 8445B Preselector may operate properly with either no DPM freque
54. ER SSG I M DeSpiritof 999 1776 fom 2028 2 SIGN HERE RECOMMENDED CHANGES TO EQUIPMENT TECHNICAL MANUALS SOMETHING WO mm mis FROM YOUR UNIT S COMPLETE ADDRESS THEN JOT DOWN THE DOPE ABOUT IT ON THIS FORM TEAR IT OUT FOLD IT AND DROP IT IN THE MAIL DATE PUBLICATION NUMBER DATE TITLE TM 11 6625 2781 14 6 30 Nov 78 BE EXACT PIN POINT WHERE IT IS iN THIS SPACE TELL WHAT IS WRONG AND WHAT SHOULD BE DOME ABOUT IT lt uwa TEAR ALONG DOTTED LINE ee ee Et SSS DA fom 2028 2 Kx e Run TW CARBON COPY O FILL IN YOUR UNIT S ADDRESS FOLD BACK e h A DEPARTMENT OF THE ARMY POSTAGE AND FEES PAID DEPARTMENT OF THE ARMY OFFICIAL BUSINESS 900 314 PENALTY FOR PRIVATE USE 9300 Commander US Army Communications and Electronics Materiel Readiness Command ATTN DRSEL ME MQ Fort Monmouth New Jersey 07703 NIT GALLOG NHVZ3l M D y FOLD BACK
55. IN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IH CLUDES ASSEMBLY NUMBER g RI OF ASSEMBLY Ai 15 AIRI DESGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN TM 11 6625 2781 14 6 PIO INTERCONNECT BOARD A5 19 5V SUPPLY Ww POWER GROUND SIGNAL GROUND 1 SEE SCHEMATIC DIAGRAM NOTES TABLE 8 3 A2 AB Figure 8 21 Power Supply and Power Line Module Schematie Diagram 8 25 8 26 Model 8445B ATR37 7050 MHz ADJ A1R36 550 MHz ADJ ATR35 SUM AMP NULL AT RAZ NULL A1R34 HAR AMP NULL 151 TEST OPR Figure 8 22 TOP VIEW FREQ OFFSET Adjustment Controls A381 TEST GPR A3R28 18 GHz ADS A3R21 EGARSE TRACKING A3R24 18 GHz ADS ASR COARSE FREG OFFSET A2R5 18 5 V AR 11 6625 2781 14 4 VIEW OPTION 003 A1R41 2050 MHz A1RAD CRM All 550 t 12 ADJ ATR39 SUM AMP NULL ATR38 HAR AMP NULL AT RAG NULL ATS2 TEST OPR A1R37 2050 MHz ATR36 556 MHz ADJ ATR38 NULL ATR34 NULL 7 NULL A151 TEST OPR Figure 8 23 Option 003 A1 Adjustment Controls 8 27 8 25 TM 11 6625 2781 14 6 1 YIG PREDRIVER ASSEMBLY 00 A2 POWER SUPPLY ASSEMBLY PE OPTION mt ALSO PIO AL DEM PRI FYER AST FON UNE HORS men OT TOU m ae n OAS ITWHRCONMEUT S
56. L Vernier control to compensate for the amount of insertion loss indicated in step 20 The Preselector and Analyzer are now calibrated at 1 5 GHz Remove cable between Preselector INPUT and Analyzer SECOND LO OUTPUT Install 50 ohm termination on SECOND LO OUTPUT connector Connect signal 10 MHz to 1 8 GHz under investigation to INPUT connector of Preselector Set LOG REF LEVEL vernier control to compensate for insertion loss using data obtained in steps 8 or 20 or the data on the PRESELECTOR INSERTION LOSS chart Figure 3 4 Low Pass Filter Operation 10 MHz to 1 8 GHz 3 of 3 3 9 TM 11 6625 2781 14 6 Model 8445B OPERATOR S CHECKS USING YIG TUNED FILTER ASAD SUKAR AGAS US UU Ig gt TRUM ANALYZER SECTION AM p m um tendi 3 1 cn en WU Vote e i Qoo UAM vee lt 5 UA WEN ae e 7 q 9 5 gt Figure 3 5 1 8 to 18 GHz YIG Tuned Filter Operation 1 of 3 3 10 Model 8445B TM 11 6625 2781 14 6 OPERATOR S CHECKS USING YIG TUNED FILTER Check that the Line Voltage Selection Card is positioned to correspond to the available line voltage Refer to information on Line Voltage Selection in Section 11 Connect interconnect cable W3 between AU X B output on Spectrum Analyzer
57. N EHE ao VDC POW ER SUPPLY The 27 7 Vrms secondary of power transformer Ti rated at 1 5 A is rectified by diodes AZVZCREGE through A 2CR amd is filtered by C4 to provide a 40 Wde unre Eulated source Ee 19 5 VDC POWER SUPPLY The 40 Wade source is electronically regulated to prowide a 1t vdc source The monolithic integrated circuit AZU1 is a voltage regulator used to comtrol the series regulator transistor AZ Q1 Instantaneous current limiting is pro vided by A 2ZR29 connected in series with the emitter of A2Q R 1 If output current is excessive the voltage drop across A 2R29 biases off the base circuit of a control transistor im 72171 which in turn reduces the conductance of A 2 Q1 limiting the overload current Such an overload should also burn out fuse A 2F1 Over voltage protection is provided by breakdown diodes A2YRS and A2V R The voltage divider consisting of AZRS A2R27 and AZRZ2S provides refer ence voltage for the voltage controlling circuitry in the IC to provide adjust ment of the 1 9 5 Vdc output 23 VOLT POWER SUPPLY The 27 7 Vrms secondary of power transformer Ti rated at O 1 A is rectified by diodes AZCR1IO through AZCR12 and is filtered by AZCS3 to provide a 4O volt unregulated source The 40 volt source is electronically regulated to 42 13 volts by a series regulator circuit using a 23 7 volt breakdown diode as a reference element Overload protection is provided by fuse E2 Ov
58. OU AP PON ile S vio Y ASSY eM L P O A1 DPM DRIVER ASSEMBLY OPTION 003 ONLY A5 YIG DRIVER ASSEMBLY MG IEC TO MTM BI AL PREDA VER ASSY Wa Y DIUINO Pr 5 NTFRCCNMECT SCARED PA A3 DATVER A557 DAMES SER SUPPLY ASS THER KSSY i m 20 E j m Toup FEDIMTERCONMECI A5 T t so tomm ty EB r BG e H pg deg mr E AM k mt UN id ewes 9 qp br i meus pog ro EU ol Pin E pee D x PRECEDENTE d T BE Gus nu P O A2 POWER SUPPLY ASSEMBLY FAD A FONTE SUPPLY ASSY MS HEWLETT PACKARD MODEL 8445B AUTOMATIC PRESELECTOR SERIAL NUMBERS PREFIXED 1404A OVERALL SCHEMATIC DIAGRAM HP PART NUMBER 08445 90112 THIS DIAGRAM IS A SUPPLEMENT FOR THE MODEL 8445B OPERATING AND SERVICE MANUAL PRINTED JUNE 1975 HP PART NUMBER 08445 90109 Figure 8 24 Overall Schematic Diagram 8 29 Model 8445B IM 11 6625 2781 14 6 APPENDIX B SERVICE NOTE NO 8555 A 1 HP MODEL 8555A SPECTRUM ANALYZER RF SECTION Serials Prefixed 1232A and Below PRESELECTOR DPM MODIFICATION HP 8555A RF Sections with serials listed above require a circuit wiring modification before proper operation of the HP Model 8445B Option 003 Preselector can be achieved The digital r
59. R CIRCUITS MANUAL CONTROL AMPL A2U2 TM 11 6625 2781 14 6 4 YIG FILTER K2 jp RF E OUTPUT O N 1 I I I I NOTES 1 OPTION 004 DELETES 1 8 GHz LP FILTER AND COAXIAL SWITCHING RELAYS SWITCH DRIVER A3 YIG DRI VER REMAINS BUT S UNUSED 2 RELAY CONTACTS CLOSED AS SHOWN WITH 8555A ce CABLE DISCONNECTED SUMMING WITH 8555A OFF OR WITH OPTION 002 SET TO REMOTE Figure 8 6 Block Diagram of 8445B With Option 002 Circuits Unshaded 8 11 8 12 Model 64456 Connect Preselector to Analyzer Turn on power to both instruments Does Preselector pilot lamp light Do power supplies read 33 to 38V at YIG pin 4 ior YIG pin Y 18 5 0 1V at ATTP1 23 0 1V at AZTP 49 t 0 17 at ASTPK 28 0 1V at YIG Pin 27 YES Set Analyzer to BAND 222020202020 205 GHz FREQUENCY 156Hz SCAN WIDTH PER DIVISION 20MHz BANDWIDTH 300kHz INPUT ATTENUATION 3048 SCAN TIME EM 10 milliseconds LOG REF LEVEL 10dBm VIDEO FILTER 2 s s s s SCAN MODE e s s s s s s INT SCAN TRIGGER AUTO BASE LINE CLIPPER 05s s 4 MAX CCW Connect 8555A 1 5 GHz 2nd LO OUTPUT to 8445B INPUT using short Fype N BNC connector cable with 1098 pad Option 002 instruments set MODE switch to AUTO STANDARD L P FILTER MODELS CHECK
60. T IT lt TEAR ALONG DOTTED LINE H IMMER i D A 1 oed 2028 2 PS SSIF YOUR QUTFI FILL IN YOUR UNIT S AODRESS FOLO BACK we e A DEPARTMENT OF THE ARMY POSTAGE AND FEES PAID DEPARTMENT OF THE ARMY OFFICIAL BUSINESS 14 USER PENALTY FOR PRIVATE USE 300 di Commander US Army Communications and Electronics Materiel Readiness Command ATTN DRSEL ME MQ Fort Monmouth New Jersey 07703 cm A M FOLD BACK REVERSE OF DA FORM 2028 2 d31I0d XVIL a a THE METRIC SYSTEM AND EQUIVALENTS NEAR MEASURE SQUARE MEASURE Centimeter 10 Millimeters 0 01 Meters 0 3937 Inches 1 Sq Centimeter 100 Sq Millimeters 0 155 Sq Inches 1 Meter 100 Centimeters 1000 Millimeters 39 37 Inches 1 Sq Meter 10 000 Sq Centimeters 10 76 Sq Feet 1 Kilometer 1000 Meters 0 621 Miles 1 Sq Kilometer 1 000 000 Sq Meters 0 386 Sq Miles MEIGHTS CUBIC MEASURE Gram 0 001 Kilograms 1000 Milligrams 0 035 Ounces 1 Cu Centimeter 1000 Cu Millimeters 0 06 C
61. TE connector center conductor to termi nal of power supply REMOTE center pin and shield now shorted together 7 Adjust A2R23 NULL for zero indication on digital voltmeter Remove short across REMOTE Center pin and shield 7 2 Model 8445B TM 11 6625 2781 14 6 5 12A REMOTE AMPLIFIER ADJUSTMENT cont d 8 Common mode adjustment a Set power supply output voltage to 10 volts b Note error voltage indicated by voltmeter c Alternately adjust A2R20 and A2R21 for a zero indication on voltmeter Remove about half the error voltage with each potentiometer 9 Differential mode adjustment a b Set power supply output voltage to zero Connect REMOTE connector center conductor to terminal of power supply Connect terminal of digital voltmeter to 2 2 Adjust A2R23 NULL for zero indication on voltmeter Set Power Supply output voltage to 10 volts Alternately adjust A2R20 and A2R21 for zero indication on voltmeter removing about half the error voltage with each potentiometer 10 Repeat steps 2 through 9 until settings are found which simultaneously satisfy all modes within a tolerance of 1 0 millivolts 11 Note and record digital voltmeter indication for each mode Common mode mV Differential mode mV Page 8 9 Figure 8 21 Service Sheet 5 Change the circuit diagram as shown in partial schematiclEigure 7 3 7 3 TM 11 6625 2781 14 6 Mod
62. TM 11 6625 2781 14 6 TECHNICAL MANUAL OPERATOR S ORGANIZATIONAL DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST FOR FILTER VARIABLE F 1414 U HP 8445B NSN 6625 00 253 4833 HEADQUARTERS DEPARTMENT OF THE ARMY 30 NOVEMBER 1978 WARNING DANGEROUS VOLTAGES EXIST IN THIS EQUIPMENT DON T TAKE CHANC ES This manual contains copyrighted material reproduced by permission of the Hewlett Packard Company All rights reserved TM 11 6625 2781 14 6 DEPARTMENT OF THE ARMY TECHNICAL MANUAL HEADQUARTERS WASHINGTON DC 30 Novembe 1978 NO 11 6625 2781 14 6 OPERATOR S ORGANIZATIONAL DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST FOR FILTER VARIABLE F 1414 U HP 8445B NSN 6625 00 253 4833 REPORTING OF ERRORS You can improve this manual by recommending improvements using DA Form 2028 2 located in the back of the manual Simply tear out the self addressed form fill it out as shown on the sample fold it where shown and drop it in the mail If there are no blank DA Forms 2028 2 in the back of your manual use the standard DA Form 2028 Recommended Changes to Publications and Blank Forms and forward to the Commander US Army Communications and Electronics Materiel Readiness Command ATTN DRSEL ME MQ Fort Monmouth NJ 07703 In either case a reply will be furnished direct to you This manual is an authent
63. TP4 equivalent to 42 000 Vdc at REMOTE input Set sweep oscillator to 2 GHz with a 0 2 GHz AF sweep and set frequency meter to 2 GHz Adjust COARSE FREQ OFFSET control A3R7 to center frequency meter dip in the YIG filter passband Adjust power supply for 413 66 Vdc 0 01 Vdc at A3TP4 equivalent to 414 00 Vdc at REMOTE input Set the sweep oscillator for 14 GHz with a 0 5 GHz AF sweep and set frequency meter to 14 GHz Adjust COARSE TRACKING control A3R21 to center the frequency meter dip in the YIG filter passband If A3R21 has insufficient range select values of A3R13 until the required A3R21 adjustment can be made Since the COARSE TRACKING and COARSE FREQ OFFSET adjustments interact repeat steps 5 through 9 Set power supply for 415 61 Vdc 30 01 Vdc at A3TP4 equivalent to 16 00 Vdc at REMOTE input Set sweep oscillator to 16 GHz with a 0 5 GHz AF sweep and set frequency meter to 16 GHz Adjust A3R24 16 GHz ADJ to center frequency meter dip in the YIG filter passband Set power supply for 417 56 Vdc 30 01 Vdc at A3TP4 equivalent to 18 00 Vdc at REMOTE input Set sweep oscillator and frequency meter to 18 GHz Adjust A3R29 18 GHz AD control to center frequency meter dip in the YIG filter passband 5 14 DIGITAL PANEL METER ADJUSTMENT Option 003 REFERENCE Service Sheet 3 DESCRIPTION The digital panel meter is first adjusted to indicate zero when the 8555A Spectrum Analyzer is adjusted to zero frequen
64. TS provides in formation required to properly adjust and align the instrument after repairs are made SECTION VI REPLACEABLE PARTS pro vides ordering information for all replaceable parts and assemblies SECTION Vil MANUAL CHANGES nor mally will contain no relevant information in the original issue of a manual This section is reserved to provide back dated and up dated information in manual revisions or reprints SECTION VIII SERVICE includes all infor mation required to service the instrument 1 5 Supplied with this manual is an Operating Information Supplement The Supplement is a copy of the first three sections of the manual and should INFORMATION be kept with the instrument for use by the operator Also included with the manual is an Overall Schematic Diagram Additional copies of both the Operating Information Supplement and the Overall Schematic Diagram can be ordered separately through your nearest Hewlett Packard office The part numbers are listed on the title page of this manual 1 6 Also listed on the title page of this manual is a Microfiche part number This number can be used to order 4 x 6 inch microfilm transparencies contains up to 60 photoduplicates of the manual pages The Microfiche package also includes the latest Manual Changes supplement and all pertinent Service Notes 1 7 SPECIFICATIONS 1 8 Specifications for the instrument are listed in These are the performance standards the ins
65. a transis tor stage first determine if the emitter base junc tion is biased for conduction forward biased by measuring the voltage difference between emitter and base When using an electronic voltmeter do not measure directly between emitter and base there may be sufficient loop current between the voltmeter leads to damage the transistor Instead measure each voltage separately with respect to a common point e g chassis If the emitter base junction is forward biased check for amplifier ac tion by short circuiting base to emitter while ob 11 6625 2781 14 6 serving collector voltage The short circuit elimi nates base emitter bias and should cause the trans istor to stop conducting cut off Collector voltage should then change and approach the supply vol tage Any difference is due to leakage current through the transistor and in general the smaller this current the better the transistor If the collector voltage does not change the transistor has either an emitter collector short circuit or emitter base open circuit 8 26 Transistor and Diode Markings Figure 8 2 illustrates examples of diode and transistor marking methods In addition the emitter lead for bipolar transistors is identified on the printed cir cuit boards 8 27 Printed Circuit Board Markings On the printed circuit board a square pad is etched around one pin of some components to show how the compo nent must be installed when replace
66. alyzer RF Section has a 2 01 4 4 GHz YIG tuned first local oscil lator LO and selects either a 550 or 2050 MHz first IF depending on the frequency band in use The untuned input circuitry of the 8555A accepts any signals from 10 MHz to over 18 GHz These signals are mixed with the first LO as well as with harmonics of the LO In some cases this presents problems interpreting several signals being dis played The preselector is used to eliminate un wanted responses on the CRT display The stan dard Preselector uses a low pass filter for the fre quency range of dc to 1 8 GHz and a YIG resonator as a nominal 30 MHz bandwidth tunable mic rowave filter capable of operating over the fre quency range of 1 8 18 GHz The driving voltage used to tune the YIG first LO in the 8555A is mod ified and used to tune the YIG filter in the Preselec tor By tracking the Preselector with the Spectrum Analyzer tuning virtually all image multiple and spurious responses can be eliminated from the dis play CAUTION Installation of a coaxial attenuator or a coaxial isolator at the Preselector INPUT is recommended when operating with signal sources that are not capable of ab sorbing their own reflected power Any signals outside the passband of the Pre selector input will be reflected back to the source 3 5 Multiple responses occur when the local oscil lator harmonics cause more than one display for a single input frequency For example whe
67. ansistor is comparable to the control grid cathode relationship in a vacuum tube The base emitter junction is essentially a solid state diode for the transistor to conduct this diode must be forward biased As with simple diodes the forward bias polarity is determined by the materi als forming the junction Transistor symbols on schematic diagrams reveal the bias polarity re quired to forward bias the base emitter junction The B part of Figure 8 1 shows transistor symbols with the terminals labeled The other two columns compare the biasing required to cause conduction and cut off in NPN and PNP transistors If the transistor base emitter junction is forward biased the transistor conducts However if the base emitter junction is reverse biased the transistor is cut off open The voltage drop across a forward biased emitter base junction varies with transistor collector current For example a germanium trans istor has a typical forward bias base emitter vol tage of 0 2 0 3 volt when collector current is 1 10 mA and 0 4 0 5 volt when collector cur rent is 10 100 mA In contrast forward bias vol tage for silicon transistors is about twice that for germanium types about 0 5 0 6 volt when collec tor current is low and about 0 8 0 9 volt when collector current is high 8 25 Figure 8 1 Part A shows simplified versions of the three basic transistor circuits and gives the characteristics of each When examining
68. aterial shows signs of stress notify the carrier as well as the Hewlett Packard office Keep the ship ping materials for carrier s inspection The HP ASSEMBLY A6 Operating voltage is shown in module window office will arrange for repair or replacement with out waiting for claim settlement 2 5 PREPARATION FOR USE 2 6 Power Requirements 2 7 The Model 8445B requires a power source of 100 120 220 or 240 Vac 5 10 48 to 440 Hz single phase 440 Hz operation requires a special H16 440 Hz fan modification Contact your nearest HP representative Power consumption is less than 110 volt amperes 2 8 Line Voltage and Fuse Selection 2 9 Select the line voltage and fuse as follows a Measure the ac line voltage and fuse as fol lows b Refer to At the instrument s rear panel power line module select the SELECTION OF OPERATING VOLTAGE Disconnect power cord and slide cover to left to gain access to fuse compartment Remove line fuse by pulling outward on FUSE PULL To select operating voltage a Rotate FUSE PULL to left and remove PC board with long nose pliers b Orient PC board so that desired vottage marking is on top left hand side Push PC board firmly into its slot 4 Rotate FUSE PULL back to its normal position and insert fuse in holder Be sure to use the correct fuse value Figure 2 1 Line Voltage Selection 2 1 TM 11 6625 2781 14 6 line voltage 100 V 120 V 220 V
69. ctor The or mixing offset amplifier provides an offset voltage to match the mixing mode in the analyzer The output from the offset amplifier is applied through a 2 05 GHz IF or 550 MHz IF offset network to the summing amp lifier The IF offset is a resistive network controlled by Band Code bit D from the analyzer The output is a voltage proportional to the analyzel s 1st IF offset The frequency to voltge ratio is 1 025 GHz Volt The Summing Amplifier combines the output of the Harmonic Number Amplifier with the output from the 2 05 GHz 550 MHz IF Offset Net work to produce an output voltage level to the YIG Driver that is proportional to the frequency to which the analyzer is tuned The Summing Amplifier has unity gain 1 with an output voltage level prop ortional to frequency by a ratio of 1 025 GHz volt Standard 8445B models utilize Band Code bits A B D and E from the 8555A to automatically switch the LP filter in place of thetunable YIG filter in the Preselector RF signal line when the 0 2 0 GHz band is selected The front panel FREQ OFFSET adjustment is used to trim the YIG filter magnet current to correct for slight variations in filter frequency The screw driver TRACKING adjustmentis used if the Pre selector is not tracki en low and high frequency bands 2222 2 OPTION 004 MODELS When Option 004 is ordered the 1 8 GHz low pass filter and the coaxial switching relays are deleted The Coaxial Switch Control a
70. cy and then to indicate 18450 when the 8555A is set to 18 450 GHz 5 8 Model 8445B Model 8445B TM 11 6625 2781 14 6 ADJUSTMENTS 5 14 DIGITAL PANEL METER ADJUSTMENT Option 003 Cont d DIGITAL MULTIFUNCTION VOLTMETER UNIT W3 CABLE TO AUX B CONNECTORS AT BACK Figure 5 4 Digital Pand Meter Adjustment Test Setup EQUIPMENT Digital Voltmeter 5 HP 3480B 3484A NOTE Before adjusting digital panel meter circuits the 8555A Spectrum Analyzer circuits must be correctly adjusted according to 8555A Manual instructions 1 Couple the 8555A to the 8445B After applying power to the instruments allow 30 minutes for the circuits to stabilize 2 Remove top cover of the 8445B Preselector 3 Connect the lead of the multifunction digital voltmeter to the Teflon insulated standoff to which the blue white wire is connected at the right hand rear portion of the A7 chassis Connect the lead to the standoff to which the black white wire is connected 4 Set the 8555A Spectrum Analyzer to BAND n 1 2 05 GHz If the Preselector has Option 002 panel controls set MODE switch to AUTO operation Adjust the 8555A FREQUENCY control to obtain a reading of 0 000 Vdc 30 001 Vdc on the multifunction digital voltmeter 5 If the Preselector DPM does not read within one count of zero adjust the Z control on the rear panel surface of the DPM to produce 00000 1 count on the DPM
71. d interconnect cable 3 Remove AZ assembly from Preselector Check for a short on the 1 9 5 wW line external to the power supply xXx A 2 pin 3 to ground Typical resistance is 1200 ohms Check AZW RS and w RYE for shorts Install AZ assembly apply power and check for a voltage drop of 3 48 volts across diode A gt Re Check for voltage drop of approximately O 2 volt across A 2R 292 lt for equal voltage levels 3 Wo between ground and reguilator module A 22 1 1 pins 2 and 3 23 VOLT SUPPLY fuse AVEF2 is open remove input lime voltage from Preselector Remove Al A2 and AS assermblies Check Aa 2T EDI to A 2T EX for short if shorted check RG Check for a short om the volt line external to the power supply XAZ pin 9 to ground gt Typical resistance is 4 000 ohms Remove AZ and check diodes AZCRIO through 13 and capacitor for shorts or opens Check diode A 2V RS transistors A2Q9 and 10 capacitor C and resistor R25 Install A2 assembly amd apply power Check input to rectifiers for 27 7 Wrms and 23 7 C lt across x Model 8445B Figure 8 20 A2 Power Supply and Filter Switching Assembly POWER 100 120 220 CABLE 240 VAC 5x 10 we A8 to 440 Hz 27 7V RMS 8 L5 27 TV RMS 80 1 AMP XAS BOTTOM VIEW ABCDEFH JKLMNPRS 1234567 B91I011I213MI5 SERIAL PREFIX OV 991 SUPPLY REFERENCE DESIGNATIONS WITH
72. d on the 8555A RF Section either 550 GHz or 2 05 GHz is used as the 1st IF The IF 500 GHz 2 05 GHz offset network alters the input to the Summing Amplifier to compensate for the IF change This is ac complished by Band Code bit D and relay K5 Precise level corrections for an IF of 2 05 GHz are made by adjusting R37 ADJ 4 Adjustment of R36 ADJ 5 corrects for improper input level to the Summing Amplifier for an IF of 550 GHz SUMMING AMPLIFIER Summing Amplifier A1U2 combines the output from the Harmonic Number Amplifier with the output from the IF 550 GHz 2 05 GHz Network to produce a voltage proportional to the band and frequency to which the analyzer RF Section is tuned The output from the Summing Amplifier is applied to the YIG Driver Assembly A3 Service Sheet 4 LOGIC DECODERS RELAY DRIVERS Transistors A1Q1 through Q8 and their associated relays operate as logic de coders of Band Code bits from the 8555A Band Code signals of either 20 or 12 Vdc from the analyzer RF Section are utilized to control the switching of precision resistors in the circuits of the Harmonic Number Amplifier to control the output polarity of the n Amplifier and to offset the input to the Sum ming Amplifier by the IF 550 GHz 2 05 GHz Network TROUBLESHOOTING PROCEDURE EB HARMONIC NUMBER AMPLIFIER Set switch A1S1 to TEST position and check at A1TP2 for a level of O Vdc 1 m V Set switch 151 back to OPR position If test volta
73. de selection of man ual tuning automatic tuning and remote tuning of the YI G tuned filter or substitution of a 1 8 MHz low pass input filter 1 33 Option 003 A digital readout of the center frequency of the spectrum analyzer is displayed by a digital panel meter DPM on the front panel of the preselector The DPM indictes the frequency of the YIG tuned filter when voltage fed to the REMOTE input BNC connector is used to control the YIG 1 34 Option 004 The 1 8 GHz low pass filter is deleted 1 35 Option 005 The HP 11670L rigid RF Inter connect cable is deleted 1 36 Option 100 Includes a modification kit for certain Model 140 mainframes see Paragraph 2 22 and Table 2 2 to make these displays compatible with the 8445B It adds an Auxiliary B output jack tothe display mainframe 1 37 Option 200 Includes a modification kit for certain Model 140 mainframes se Paragraph 2 22 and Table 2 2 to make these displays compatible with the 8445B It adds Auxiliary A and B output jacks to the display mainframe 1 38 ACCESSORIES SUPPLIED 1 39 I 3 lists the accessories supplied with the Preselector The accessories supplied are for a standard installation which provides for the Pre selector to be mounted on an 8555A Spectrum Analyzer and fastened with a joining racket kit A different mounting installation will require a dif ferent RF cable to connect between the Preselector output and the Spectrum Analyzer i
74. display Reduce SCAN WIDTH PER DIVISION to 0 5 MHz keeping signal centered on display with FREQUENCY control Figure 3 5 1 8 to 18 GHz YIG Tuned Filter Operation 2 of 3 3 11 TM 11 6625 2781 14 6 Model 8445B OPERATOR S CHECKS USING YIG TUNED FILTER Reduce SCAN WIDTH PER DIVSION to 100 kHz center signal on display with FINE TUNE control Set LOG LINEAR switch to LINEAR and LINEAR SENSITIVITY control to 1 mV DIV Adjust Preselector TRACKING control to maximize signal on CRT display If signal is already at maximum no further adjustment of FREQ OFFSET or TRACKING is required If signal is not at maximum repeat steps 7 through 22 until a setting is found which satisfies requirements of steps 13 and 22 NOTE Incorrect tracking of preselector to the Spectrum Analyzer may be due to aging or misadjustment of the 8555A YIG Driver Assembly Follow the directions given Section V of the 8555A Operating and Service Manual under YIG Driver Adjustments To check YIG filter tuning by an external dc voltage set the 30 dBm signal source to 2 GHz and the 8555A to a band to display this frequency Disconnect the W3 interconnect cable from the rear of either the 8445B or the 8555A Apply a positive voltage from a variable dc power supply to the center connection of the REMOTE input BNC connector at the rear of the 8445B Monitor the REMOTE input vol tage with a voltmeter The signal on the CRT should peak at 42
75. dual magnetism in core structure Adjusted to center the YIG filter at 2 0 GHz for wide range tracking Adjusted for minimum filter insertion loss during power level measurements See Fig ure 3 5 TRACKING Adjusts YIG driver gain to match linear current frequency curve of YIG filter Ad justed during operational adjustments at a fre quency of 8 GHz Adjustment required to match tuning of Preselector with tuning of Spectrum Analyzer Interacts with FREQ OFFSET ad justment See Figure 3 5 INPUT Type N coaxial connector normally provided Option 001 instruments supplied with APC 7 connectors provided Option 001 instruments supplied with APC 7 connector Se Table 1 3 for optional rigid coaxial interconnect cables MANUAL TUNE COARSE Option 002 Instruments Manual YIG filter frequency tune control Sets YIG filter center frequency in manual operating mode MANUAL TUNE FINE Option 002 Instruments Fine tune control for YIG filter frequency in manual operating mode MODE Option 002 Instruments Selects Preselector mode of operation MANUAL YIG filter tuned by front panel controls AUTO Low pass filter and or YIG filter selected by control signals from analyzer RF Sec tion YIG frequency tuned by signal from RF Sec tion REMOTE YIG filter tuned by input vol tage to BNC connector on rear panel LOW PASS except Option 004 Selects 1 8 GHz low pass filter Inhibits Spectrum Analyzer control of Pr
76. e selector DIGITAL PANEL METER Frequency Readout Option 003 Instruments Indicates center frequency of the YIG filter pass band in Manual or Remote Mode In AUTOMATIC Mode indicates center frequency of 8555A Spec trum Analyzer reads zero above 18 GHz or in LOW PASS Mode Figure 3 3 8445B Controls Connectors and Indicators 2 of 3 3 5 11 6625 2781 14 6 Model 8445B 84456 REAR PANEL FEATURES Air Intake Maintain at least 3 inch clearance from surrounding objects Power Module Assembly 100 120 220 and 240 Vac 5 10 48 to 440 Hz 100 VA max Line Input Connects to external ac power supply Line Voltage Selector Card Printed circuit board used to match the available line voltage to the transformer primary Fuse extractor and selector Lock Prevents line voltage selector card from being removed until fuse is extracted Line Input Fuse Rating of fuse to be used is marked on rear panel near the Power Module Assembly TUNING CONTROL REMOTE Input for remote tuning voltage to YIG filter Enabled when Spectrum Analyzer is not operating power off when interconnect cable is discon nected or on Option 002 when the mode switch is set to REMOTE Type BNC connector YIG filter frequency to voltage ratio 1 0 GHz Volt TUNING CONTROL SPECTRUM ANALYZER Input Input control voltage for selection of YIG or low pass filter YIG tuning voltage and band code information Disco
77. e YIG filter maybe tuned by external sweep vol tage or manually tuned by front panel controls Op tion 002 A Digital Panel Meter Option 003 nor mally indicates the Spectrum Analyzer center fre quency In remote or manual modes the indicated frequency is that to which the YIG filter is tuned 1 29 OPTIONS 1 30 The Standard 8445B An Automatic Pre selector consisting of a YIG tuned tracking filter operating between 1 8 and 18 GHz and a dc to 1 8 GHz low pass filter The input and output ports of the instrument are Type N coaxial connectors In duded is an HP 11670L rigid coaxial cable for con nection of the 8445B output to an 8555A spectrum analyzer when the preselector is mounted above the 8555A with a joining bracket kit For other mount ing configurations order 8445B Option 005 to delete the 11670L Then select the appropriate cable indi cated in Table 1 4 1 31 Option 001 The standard Type N input and output port connectors are replaced by Precision APC 7 connectors An HP 11670M interconnect cable with APC 7 connectors is induded in place of the HP Number 11670L cable An 8445B Option 001 must be used with an 8555A Option 001 which has an APC 7 RF Input connector An APC 7 termi nated RF interconnect cable can be ordered from Order Option 005 to delete the standard Type N interconnect cable 1 32 Option 002 A front panel MODE switch and two MANUAL TUNE controls are added to the Automatic Preselector to provi
78. e instrument is being returned to Hewlett 4 inch layer around all sides of the instru Packard for servicing attach a tag indicating the ment to provide firm cushion and prevent type of service required return address model movement inside the container Protect the number and full serial number Also mark the con control panel with cardboard tainer FRAGILE to assure careful handling In any correspondence refer to the instrument by model d Seal the shipping container securely number and full serial number e Mark the shipping container FRAGILE to 2 33 Other Packaging The following general assure careful handling Table 2 2 Modification of Display Sections for Presdector Compatibility DISPLAY SECTION Modification Kit HP Part Number HP Model Number Serial Prefix 1105A and below 1047A and below All 00140 69505 140T 141T 1405 1415 Option TG 1 1405 1415 Except Option TG 1 Instruments Included with 8445B Option 001 Included with 8445B Option 002 All 00140 6950 Model 8445B TM 11 6625 2781 14 6 SECTION Ill OPERATION 3 1 INTRODUCTION 3 2 This section describes the HP 8445B Automa tic Preselector operation with an HP 8555A 8552 140 Spectrum Analyzer system It de scribes front and rear panel controls and connectors and outlines operation of the system 3 3 SPECTRUM ANALYZER PRESELEC TION 3 4 The 8555A Spectrum An
79. eadout driver in the 8445B requires an input signal from the A4 YIG Driver Assembly in the 8555A This modification consists of adding a jumper wire on the plug in A4 assembly plus adding a wire between A4 output connector and the rear panel P5 Auxiliary B connector PROCEDURE 1 2 5 Remove top and bottom covers from the 8555 Remove the A4 A5 and A6 board assemblies so that A4 can be modified and easy access to connector can be obtained Connect an insulate inch jumper wire between A4U7 pin 6 and pin 8 on the A4 board connector Refer to Connect as insulated 4 inch wire between 10 4 pin 8 on interconnect board and rear panel Preselector connector P5 pin 7 Refer to Figure B 2 This completes the modification Replace all board assemblies and top and bottom covers ELECTRICAL CHECK 1 2 3 4 With 8555A installed into Display Section turn on power Center LO feed thru signal on CRT display With a dc voltmeter measure the voltage at AUXILIARY B on rear panel connector P5 pin 7 Voltage should be 7 50 0 05 With frequency dial at 4100 MHz on the LO scale voltage at P5 7 should be 15 00 0 05V Change your Operating and Service Manual per the partial schematic of the A4 assembly shown in B 1 TM 11 6625 2781 14 6 Mode 18445B LIEN DRIVER TO P5 PIN 7 Figure B 1 Modified A4 Board Figure B 2 Connection to 10 4 8 1 I I L gt 2S 2 E T
80. ects the input voltage so that the frequency calibration of the COARSE tune control reads correctly Operational amplifier A2U2 is an inverting amplifier with unity gain REMOTE CONTROL BUFFER AMPLIFIER Remote control of the YIG Filter tuning is possible when the Analyzer is either off disconnected from the Preselector or if the Preselector incorporates Option 002 and the front panel switch is set to REMOTE The Remote Control Buffer Amplifier produces a voltage at its output equal to the voltage difference ap plied across the floating BNC remote input connector divided by 1 025 A2U3 and its associated circuitry form a standard unity gain differential amplifier The output of A2U3 is routed to the Automatic Switching Control see 4 below or through the MODE switch to the YIG Driver input AUTOMATIC SWITCHING CONTROL Standard Models Automatic Switching Control relay connects the YIG Driver input to either the YIG Predriver output or to the Remote Control output For the Standard 8445B relay driver A3Q1 is provided t 20 volts from the 8555A RF Section through interconnect cable W3 The 20 volts turns on A3Q1 and energizes relay A3K1 With A3K1 energized the Predriver output is routed through contacts 5 and 3 and through the interconnect wiring to the YIG Driver input If the 420 volts is removed from A3Q1 by either turning off the 8555A or disconnecting Auxiliary B interconnect cable W3 relay A3K1 de energizes and
81. ed with Option 005 Description 7 1 2 feet 3 wire Ac Line Cord Rigid Coaxial Cable Connects Preselector RF output to Spectrum Analyzer RF Input Type N connectors 20 inch Control Cable interconnects Preselector with Spectrum Analyzer 0 5A 220 240 Vac Hardware and parts for strapping Preselector to Spectrum Analyzer TM 11 6625 2781 14 6 M ode18445B Figure 1 3 RF Interconnect Cable Table 1 4 RF Interconnect Cable Information Preselector Analyzer With feet on Preselector With feet on Preselector Rack Mounted Rack Mounted With J oining Bracket Kit With J oining Bracket Kit Cable supplied with kit except when Option 005 ordered Cable supplied with Option 001 instruments 1 44 WARRANTY 1 45 The 8445B Automatic Preselector is war ranted and certified as indicated on the inner front cover of this manual and in Appendix A For further information contact the nearest Hewlett Packard office addresses are provided on the last page and 1 6 Connector HP Part Number Dimension of X Figure 1 3 Inches Cm Type 11670C 11670D 11670G 11670H 11670L 11670M office addresses are provided on the last page and rear cover of this manual 1 46 RECOMMENDED TEST EQUIPMENT 1 47 Table 1 5 lists the test equipment and acces series required to check adjust and repair the Pre selector If substitute equipment is used it must meet the Minimum Specification
82. ed with the panel FREQ OFFSET control Linearity Correction The current of the YIG magnet is essentially linear from 1 8 GHz at 70mA to 18 GHz at 700 mA 25 7 mA GHz However above approximately 14 GHz the magnet core starts to saturate To correct for this as the input voltage approaches the 14 7 V zener voltage of VR2 the zener conducts shunting R3 and R8 across the U1 input impedances R21 and R9 increasing the gain of U1 and therefore the YIG current Another similar breakpoint is developed when the input voltage approaches the zener voltage of VR3 The result is a linear input voltage frequency response for the YIG filter The 16 and 18 GHz ADJ resistors R24 and R29 are vernier adjustments on the VR breakdown voltage points q 28 VOLT YIG HEATER SUPPLY When a YIG requiring an internal heater is used the 28 V power supply pro duces the required heater current The unregualted 40 volt source is regulated to approximately 0 7 volts less than the VR6 breakdown diode voltage The circuit is included on all A3 assembly boards even if the YIG supplied requires no heater TROUBLESHOOTING PROCEDURE YIG DRIVER ASSEMBLY A3 When a malfunction has been isolated to the YIG Driver Assembly perform the following procedure Connect Preselector to Analyzer apply power and allow at least 30 minutes for equipment to stabilize Make all voltage measurements in reference to A3TP2 common ground test point EQUIPMENT REQUIRED 8555 A
83. el 8445B 5 12A REMOTE AMPLIFIER ADJUSTMENT Cont d PIO PIO POWER INTERCONNECT PIO YIG SUPPLY ASSY A2 BOARD A5 FILTER ASSY A4 li 4 t Figure 7 2 Partial Schematic correction for Service Sheet 4 P O CHANGE C k m REMOTE CONTROL BUFFER AMPL RESISTOR ARRAY R15 t I i 154 I DPM TE PREDRIVER j OUTPUT lt S 3 203 NULL v 8 Qc TOP VIEW 6 I 1 8 2008 7 1 19 5 4D 2 FROM X 3 56 5 PIN L 4 5 TIERS AN A zr E CLUDES ASSEMBLY NUMBER OF ASSEMBLY Al MEN TT 5 AIRI DESIGNATIONS OF OTHER COMPONENTS ARE ETE AS SHOWN Figure 7 3 Partial schematic correction for Service Sheet 5 P O CHANGE C 7 4 Model 8445B TM 11 6625 2781 14 6 SECTION VIII SERVICE 8 1 INTRODUCTION 8 2 This section provides instructions for trou bleshooting and repair of the HP 8445B Automatic Preselector It indudes general servicing hints and information simple block diagrams with a brief dis cussion of common Preselector systems a Trou bleshooting Block Diagram with an accompanying trouble isolation procedure assembly photographs with component identifications and Service Sheets each with circuit explanations and servicing infor mation Line voltage is always present on termin als induding the power input connector fuse holder power switch etc In add
84. ervoltage protection Provided by breakdown diode 12047 RG TROUBLESHOOTING PROCEDURE When za malfunction has been isolated to ome of the three power supplies or to isolate a malfunction im ome of the supplies use the following procedure Make all voltage measurements in reference to ASTP2 common ground point EQUIPMENT REQUIRED Multi function Mieter o HIP LUE SG CM Li Ge2s 27ea1 14 6 Rodel S4455B VOLT SUPPLY DMiscommect interconnect cable WS COption O02 set to AUTO gt Remove line voltage to Preselector Remove Fuse AZF 1 to isolate 40 WVW from 119 55 V supply fuse open check 19 5 77 supply Remove Al and A3 boards Resistance A 1TPG to AZVTPS should read approximately 59K ohms Remove AZ amd check diodes A 2CRS through 9 amd capacitor 72 4 for shorts or opens Replace AZ apply power to Preselector and make quick check for unloaded voltage AZTFPtes to ASTPS of approximately 55 volts them turn off power If voltage as low check transformer secondary grece and black wires for 27 7 Wrms Replace A 2F 1 Check A2 for short by replacing A 2 reconnecting power and checking for approximately 34 volts from A 2TPG to A x TE Repeat adding Al and checking for approximately 34 volts at A Z IE lt Z 19 5 VOLT SUPPLY Check fuse A2F1 If not open check for required approximate 33 voits from A2TPG to A2 TP S5 Remove line voltage an
85. ess positive resulting in either upward or downward current flow in the coils Reversal of current direction reverses the relay contacts When test point E is highly positive the relays are in the YIG Filter position If any of the four A D or E Band Code bits is positive 1 or 420 V the relays are driven to the YIG Filter position If all four bits are negative 0 or 12 V or if there are no bits A2Q2 is either reverse or zero biased and the relays reverse connecting the Low Pass Filter to the front panel ports manuac CONTROL BUFFER AMPLIFIER The Manual Control Buffer Amplifier A2U2 is not operative in Standard Mod els With Option 002 manual controls are added See If the panel MODE switch S2 is in the MANUAL position the base of A2Q6 is grounded through A2R16 forward biasing A2Q6 and driving the coaxial relays into the YIG Filter position The COARSE and FINE controls feed the required 1 025 GHzN to the YIG Driver to tune the YIG Filter The manual COARSE and FINE potentiometers together control dc bias voltages to amplifier A2U2 to produce the necessary 1 025 GHZ V required to tune the YIG Filter manually The COARSE tune control is calibrated in frequency from to 20 GHz The FINE tune control is calibrated from 500 to 500 MHz The resistive networks composed of A2R7 A2R11 and A2R12 provide a voltage offset that is equal to 500 MHz With the FINE control centered 0 MHz the resulting voltage offset corr
86. ge level at both the inverting terminal pin 2 and the non inverting terminal pin 3 The levels should not dif fer by more than 10 mV If the voltage levels are not within 10 mV check the external circuitry and components If the external circuitry input Amplifier Characteristics CHARACTERISTIC COMMON OMMON OMMO BASE _EMITTER COLLECTOR Input Impedance 302 502 502 500Kn Output E Impeda c 300Ka sOOKQ 30 soa 10000 Voltage Gain 500 1500 300 1 1 2 5 50 2048 30d8 10dB 20dB Emitter Follower Current Gain Power Gain Model 8445B signal operating voltages feedback resistors ap pears normal replace the operational amplifier 8 31 ELECTRICAL MAINTENANCE 8 32 Perform the electrical checks and adjust ments periodically and after repair or component replacement 8 33 MECHANICAL MAINTENANCE 8 34 Inspect the air filter at the rear of the in strument frequently and clean it before air flow is restricted To clean the filter wash thoroughly in warm water and detergent Air dry filter before in stalling it on the instrument Transistor Biasing CUTOFF CONDUCTION V ov V V 0 N CONTROL MAIN CURRENT CURRENT NPN COLLECTOR BASE EMITTER PNP COLLECTOR BASE EMITTER Figure 8 1 Transistor Characteristics and Biasing 8 6 Model 8445B FIELD EFFECT TRANSISTORS BLACK EPOXY META ETAL CASE PLASTIC METAL CASE
87. ges are out of tolerance see Paragraph 5 9 for adjustment procedure Connect voltmeter to 1 1 Select spectrum analyzer BAND 1 550 GHz and SCAN WIDTH to ZERO Adjust analyzer FREQUENCY control for an indicated voltage level of 5 000 1 mV at 1 1 Connect the voltmeter to A1TP2 and check for a level of 2 000 Vde 2 mV Select analyzer bands n 2 and check for a level of 4 000 3 mV then bands 3 for 6 000 Vdc 4 mV and finally bands n 4 for 8 000 Vdc 5 mV Amplifier A1U 1 has a gain of 0 4n with n controlled by Logic Decoder Relay Drivers see Table 8 4 If improper Har monic Number Amplifier action is indicated see Paragraph 8 30 for Opera tional Amplifier Troubleshooting Procedure or AMPLIFIER Set YIG Driver Assembly switch A3S1 to TEST position and check voltage at AITPS5 for a level of 1 mV If test voltages are out of tolerance see Paragraph 5 9 for adjustment procedure Set switch A3S1 to OPR position and select BAND n 1 550 GHz on analyzer RF section Check voltage level at A1TP5 for 9 0 0 3 V Switch analyzer to BAND n 1 550 GHz and check for a 9 0 Vdc 0 3 V level at A1TP5 Switch analyzer from BAND n 1 through n 4 A1TP5 voltage readings should be 9 0 Vdc 0 3V on all bands showing positive polarity on n bands and negative polarity on n bands Amplifier A1US has a gain of 1 at all times
88. i tion when the instrument is on energy available at many points may result in personal injury or death when contacted 8 3 ASSEMBLY SERVICE SHEETS 8 4 The schematics are arranged by service sheets The service sheet numbers appear in the lower righthand corner of schematics large number above assembly number Included in the service sheet is the schematic as well as the accom panying drcuit theory component parts location photo and schematic level troubleshooting A list of foldouts diagrams and service sheets cross referenced to assemblies is given irj Table 8 1 Bold number letter combinations such as indicate Service Sheet and lettered circuit points of inter connection Numbers in black squares such asl indicate circuits discussed in theory of operation and in troubleshooting procedures 8 5 PRINCIPLES OF OPERATION 8 6 Information relative to general principles of Preselector operation with common options is in cluded with the simplified block diagrams of Fig ures 8 4 and 8 5 Additional circuit descriptions in a more detailed form are given in the individual Service Sheets 8 7 TROUBLESHOOTING 8 8 Servicing the Preselector is made easier by the inclusion of general service hints and informa tion plus a simplified block diagram of possible Pre selector systems with test points useful in isolating troubles in a simple step by step method to deter mine a faulty assembly When a faulty assembly is
89. ication of the manufacturer s commercial literature which through usage has been found to cover the data re quired to operate and maintain this equipment The manual was not prepared in accordance with military specifications therefore the for mat has not been structured to consider categories of maintenance TABLE OF CONTENTS Page INTRODUCTION 0 1 MU E 0 2 EDAM SIN RU w Ga E a 0 3 Forms and Records ores erect Puan kaa Bale en eed 0 1 0 2 Administrative Storage ccd ok ee eed I e ERR RR Ex Eee eee 0 1 0 5 Destruction of Army Electronics 1 21 2 2 0 d Reporting Equipment Improvement Recommendations EIR 0 1 Items Comprising an Operable 2 2 m This manual supersedes TM 11 6625 2865 14 amp P 26 J anuary 1978 i ii blank 8445B Section GENERAL INFORMATION Introduction 1 7 Specifications f 5 Safety Considerations General n Operation Service L oeni by 1 24 Option 003 Instruments Only b 1 27 Description ptions 38 Accessories Supplied i nas Required but not Supplied Equipment Available
90. includes a Summing Amplifier and a YIG Current Driver Amplifier The voltage to the Summing Amplifier from the YIG Pre driver is a negative voltage of 1 025 GHz V This linear voltage frequency input in conjunction with FREQ OFFSET controls TRACKING controls and two breakpoint controls process the YIG magnet current to produce an overall linear voltage frequency response of the YIG filter The YIG frequency coil current relationship is approximately 25 7 mA GHz The YIG magnet current flows through R12 and R13 Q4 and the magnet coil Negative tuning voltages from the predriver are inverted to positive by U1 and control the conduction of Q4 The YIG current Q4 allows to flow is partially controlled by the gain of U1 This is basically the ratio of R11 to R9 or approximately 9 1 The panel FREQ OFFSET control feeds a small positive bias to the inverting input of U1 and is used as a manual control for compensation of the YIG current It is used to set the YIG on frequency at 2 GHz when checking tracking The internal COARSE TRACKING and the panel TRACKING controls help to determine the gain of U 1 and also the slope of the YIG magnet current With TRACKING at zero the COARSE TRACKING is adjusted to tune the YIG on frequency at 14 GHz outlined in In normal operation the FREQ OFFSET is used to tune the YIG at 2 GHz and the panel TRACKING control is adjusted to tune the YIG to frequency at 8 GHz Any further trimming that maybe necessary is accomplish
91. ing 0 5 V gate Vertical Input Impedance 75K ohms HP 8755A Swept Ampli tude Analyzer 180D Option 807 Display 11664A Detector 11665A Modulator Swept Frequency Indicator 6 dB Coaxial HP 8491B Coaxial Attenuator Attenuator Option 006 10 dB Coaxial Frequency Range Dc 18 GHz HP 8491B Coaxial A Attenuator Attenuator Option 010 Clip on Dc Current Range 1mA 10A HP 428B Frequency Range Dc 18 GHz Milliammeter Accuracy 3 of full scale A Adjustments T Troubleshooting P Performance 1 8 Model 8445B TM 11 6625 2781 14 6 SECTION INSTALLATION 2 1 INTRODUCTION 2 2 This section includes information on the initial inspection preparation for use and storage shipment instructions for the HP Model 8445B 2 3 INITIAL INSPECTION 2 4 Inspec 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 mechanically and electrically The contents of the shipment should be as shown in Procedures for checking electrical performance are given in Sec tion IV If the contents are incomplete if there is mechanical damage or defect or if the instrument does not pass the electrical performance test notify the nearest Hewlett Packard office If the shipping container is damaged or the cushioning m
92. ire modification for Preselector compatibility Refer to The modification consists of adding a cable assembly to the Display Section This cable connects between the Auxiliary B output con nector on the rear panel of the 8555A RF Section and the rear panel of the Display Section 2 26 8555A RF Section 2 27 Spectrum Analyzer RF Sections with Serial Prefixes 1232A and below must be modified per Service Note 8555A 1 for compatibility with 8445B Option 003 instruments See Appendix B 2 3 TM 11 6625 2781 14 6 Model 8445B 2 28 STORAGE AND instructions should be used for repackaging with commercially available materials 2 29 Environment 2 30 The instrument should be stored in a clean a Wrap the instrument in heavy paper or dry environment The following environmental plastic If shipping to a Hewlett Packard limitations apply to both storage and shipment office or service center attach a tag indicat Temperature 40 to 75 ing the type of service required return ad Humidity lt 95 relative dress model number and full serial Altitude 25 000 feet number 2 31 Packaging b Use a strong shipping container A double wall carton made of 350 pound test 2 32 Original Packaging Containers and mat material is adequte erials identical to those used in factory packaging are available through Hewlett Packard offices If Use enough shock absorbing material 3 to th
93. ition the YIG filter is tuned by a GHzNV voltage applied to the REMOTE input BNC connector on the rear panel of the Preselector n the LOW PASS position the 1 8 GHz low pass filter is connected in place of the YIG filter in the Preselec tor RF line In the MANUAL position the YIG filter can be used as a stand alone 1 8 to 18 GHz filter tuned manually with the COARSE and FINE man ual tuning dials to any selected frequency in this band If a Preselector has both Option 002 and Op tion 003 in the AUTO switch position with the Spec trum Analyzer off or with the interconnect cable W3 disconnected the DPM will read 2050 5 COMPREHENSIVE MODELS The 8445B Automatic Preselector may incorporate both Options 002 and 003 In this case the unshaded DPM circuits of LEigure 8 5l would be added to the circuits shown in Figure 8 6 Such a comprehensive system is diagramed in the Comprehensive Block Diagram of Figure 8 8 8 9 TM 11 6625 2781 14 6 Model 8445B FAN T1 m na v JG np YIG LP SWITCHING RELAYS LP FILTER FREQ COARSE FINE MODE A4 YIG TRACKING OFFSET TUNING TUNING SWITCH INPUT Figure 8 4 Top View of 8445B With Option 002 Panel Switches and Controls Model 8445B M YIG RF i INPUT L8 18 GR 5 YIG FILTER 22 O To QUTPUT E N L 8 GHz LP N LC FILTER dc
94. l interruption of the earth ground is prohibited Servicing this instrument often requires that you work with the instrument s protective cov ers removed and with ac power connected Be very careful the energy at many points in the instrument may if contacted cause personal injury CAUTION BEFORE SWITCHING ON THIS INSTRU MENT make sure the instrument s ac input is TM 11 6625 2781 14 6 set to the voltage of the ac power source BEFORE SWITCHING ON THIS INSTRU MENT make sure that all devices connected to the instrument are connected to the pro tective earth ground BEFORE SWITCHING ON THIS INSTRU MENT make sure the line power mains plug is connected to a three conductor line power outlet that has a protective earth ground Grounding one conductor of a two conductor outlet is not sufficient BEFORE SWITCHING ON THIS INSTRU MENT make sure the ac line fuse is of the re quired current rating and type normal blow slow blow etc 1 19 INSTRUMENTS COVERED BY MANUAL 1 20 Attached to the instrument is a serial number plate The serial number is in two parts 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 all identical in struments it changes only when a change is madeto the instrument The suffix however is assigned sequentially and is different for each instrument The contents of this manual apply to instruments wi
95. ltage should be 4536 6 2 0 mV 1534 6 4538 6 mV 5 5 TM 11 6625 2781 14 6 Model 8445B ADJUSTMENTS 5 12 YIG OR DPM PRE DRIVER ADJUSTMENT Cont d 12 Set 151 and 152 to OPR A3S1 to TEST and to BAND n 1 1F 550 GHz 13 Adjust Spectrum Analyzer FREQUENCY for 3 000 V at A1TP7 in Preselector 14 Check voltage at A1TP7 versus BAND setting A1TP7 Voltage Lower Limit Upper Limit 1 550 GHz 2 998 n 1 IF 2 05 GHz 2 998 1 2 05 GHz 2 998 n 2 IF 2 05 GHz 5 997 2 2 05 GHz 5 997 n 3 IF 2 05 GHz 8 996 n 3 IF 2 05 GHz 8 996 i 4 2 05 GHz 11 995 4 2 05 GHz 12 005 V 11 995 15 S amp to BAND 1 1 550 GHZ and adjust FREQUENCY control for 3 000V at AITP8 16 Check voltage and A1TP8 versus BAND setting Use same limits as in step 14 17 Set A3S1 to OPR 5 13 YIG DRIVER ADJUSTMENT REFERENCE Service Sheets 4 and 5 DESCRIPTION The YIG Driver is adjusted for linear frequency tracking with voltage Course Tracking and Course Offset controls are adjusted for proper YIG Driver tuning sensitivity The YIG linearity correction breakpoints are adjusted to compensate for saturation in the YIG core at thehigher frequencies 5 6 Model 8445B TM 11 6625 2781 14 6 ADJUSTMENTS 5 13 YIG DRIVER ADJUSTMENT Cont d FREQUENCY METER 00800 o o BER OUTPUT MULTIFUNCTI ON UNIT
96. ly isolate a malfunction to one assembly Operate the Standard Preselector or Option 002 in AUTO mode with both internal assembly test switches at OPR and the 8555A set to BAND n 2 With a dc voltmeter check for the following approximate voltages TM 1 66425 5 84 7 L Test Points 1 2 ATTP5 AT1TP7 A1TP3 AITP6 AITPS 2 AZTP2 to A2TP3 A2TP4 A2TP5 A2TP6 A2TP7 A2TPE A2TPF A2TPG A3TP1 2 4 TB2 9 Model 8445B Normali Voltages 5 0 to 10 0 V 8555A LO tuned from 2 05 to 4 1 GHz 3 8 to 7 8 V when LO tuned from 2 05 to 4 1 GHz 9 V on n X bands 9 V on n X 1 7 to 5 8 V when L O tuned from 2 05 to 4 1 GHz Option 003 6 3 to 15 V when LO tuned 2 05 to 4 1 GHz Option 003 3 8 to 7 8 V when LO tuned 2 05 to 4 1 GHz Option 003 9 V on n bands 9 V on n X bands Option 003 1 7 to 5 8 V when LO tuned 2 05 to 4 1 GHz 19 5 V supply The remote control voltage value With 2 0 V to REMOTE 1 95 V Ground point With COARSE TUNING set to 20 GHz 1 95 V 23 V supply Approx 29 to 48V when switching to BAND n 1 AF 2 05 GHz Approx 2 to 34 V when switching to BAND n 1 2 05 GHz Approx 35 V at 0 GHz 31 V at 18 GHz 19 5 V Reference ground point Approx 0 01 V at 0 GHz 17 V at 18 GHz 1 7 to 5 8 V when L tuned 2 05 to 4 1 GHz Approx
97. mended model s 4 4 TEST RECORD 4 5 Results of the performance tests maybe tabu lated on the Test Record at the end of the procedures The Test Record lists all of the tested specifications and their acceptable limits Test results recorded at incoming inspection can be used for comparison in periodic maintenance and troubleshooting and after repairs or adjustments 4 6 FRONT PANEL CHECKS 4 7 Before proceeding to the performance tests the instrument must be adjusted and all controls set as spedified in the preset adjustment instructions in paragraphs 418 and 4 9 After the instrument con trols are preset proceed with the front panel checks and adjustments The instrument should perform as called out in the preset adjustment procedures be fore going on to the performance tests 4 17 through 4 20 4 8 PRESET ADJUSTMENTS 4 9 Install Preselector with Spectrum Analyzer Ensure that the line voltage selector is set to corres pond with the available line voltage refer to Line Voltage Selection n Section 1 Connect intercon nect cable between AUX B output on the Display Section and TUNING CONTROL SPECTRUM ANALYZER input on the Preselector Connect Pre selector and Spectrum Analyzer to line voltage source and apply power While the instruments are warming up make the following control settings a PRESELECTOR with manual controls Op tion 002 SPECTRUM ANALYZER BAND n 1 I F 2 05 GHz
98. ment is made The square pad indicates the following a The cathode of a diode b Emitter of a transistor C Source of an FET d Pin one of an integrated circuit e Pin one of an integrated circuit socket f Pin one of a cable connector 8 28 Operational Amplifiers 8 29 Operational Amplifiers Function Operational amplifiers are used to provide such functions as summing amplifiers offset amplifiers buffers and power supplies The particular function is determined by the external circuit connections Equivalent circuit and logic diagrams for type 741 operational amplifiers are contained in Figure 83 Circuit A is a non inverting buffer amplifier with a gain of 1 Circuit B is a non inverting amplifier with gain determined by the resistance of R1 and R2 Circuit C is an inverting amplifier with gain deter mined by R1 and R2 Circuit D contains the func tional circuitry and pin connection information along with an operational amplifier review 8 5 TM 11 6625 2781 14 6 NOTE In Circuit D it is assumed that the amp lifier has high gain low output impe dance and high input impedance 8 30 Operational Amplifier Troubleshooting Procedure When operational amplifiers are sus pected one quick check is case temperature which should not be hot to the touch If the output voltage approaches or equals either the negative or positive bias supply values the device should be suspected Measure and record the volta
99. mum input level for lt 1 dB signal compression Burnout Level gt 20 dBm Hysteresis lt 25 MHz Tuning Linearity lt 10 MHz Insertion Loss Insertion Loss except Option 004 Option 004 Table 1 2 Typical Operating Characteristics TYPICAL OPERATING CHARACTERISTICS Tracking Filter 3 dB Bandwidth Typically 20 45 MHz Tracking Filter Skirt Roll off Characteristics of a three pole filter Input VSWR Typically lt 2 0 1 8 18 GHz Typically lt 70 dBm over operating ranges with Spectrum Analyzer input attenuator set to 0 dB See 3 1 VIM Siu requency se e Function YIG filter frequency can be set by externally supplied voltage Differential input utilized to eliminate ac hum or other common mode signals which may be present on remote drive input cable Sensitivity Nominally 1 volt GHz with direction of tuning from low to high frequency Settling Time Typically within 3 MHz of final fre quency after Sms Remote Input Connector BNC female outer con ductor isolated typical versus specification values of insertion loss The typical curve is developed from eleven spot checks See paragraph 5 15 PRESELECTOR INSERTION LOSS Arc L SPECIFICATION 0GHz 2 4 8 YIG NES LP FILTER Typical Insertion Lass The following chart shows x oo Model 8445B the information cautions and warnings in this manual must be followed to
100. n a 9 5 GHz signal is fed to the analyzer RF INPUT re sponses due to the 5 3 4 2 and 3appear on the display see Figure 3 1 Follow the signal fre quency line for 9 5 GHz across the figure noting the intersections with solid lines representing mixing modes The Preselector tracks the selected mixing mode so that responses from other mixing modes are not present on the display 3 6 When the analyzer first LO is tuned to 3 GHz 2050 MHz 1st IF image res occur at different frequencies Refer toLE igure 311 F ollow ing the 3 GHz local oscillator line up the figure note intersections with solid lines representing mixing modes Each of these signals will appear at the same place on the CRT although products of different mixing modes The Preselector eliminates images by allowing only selected frequency band signals to enter the analyzer s RF INPUT and allowing only one mixing mode to be used at one time 3 7 Spurious signal responses are caused when strong signals enter the RF INPUT of the analyzer and are of sufficient amplitude to cause intermodu lation products The narrow bandwidth of the Pre selector YIG filter 30 MHz nominal acts to elimi nate spurious signal responses on the display Input signals that are farther apart than the Pre selector filter bandwidth cannot appear in the analyzer input at the same time 3 8 RECOMMENDED MIXING MODES 3 9 Table 3 1 lists the frequency ranges that the Preselector will
101. n and cor rosion Model 8445B TM 11 6625 2781 14 6 Table 8 2 Schematic Diagram Notes SCHEMATIC DIAGRAM NOTES Refer to ANSI Y32 2 Resistance is in ohms capacitance is in microfarads and inductance in millihenries unless otherwise noted Part Of Asterisk on component denotes a factory selected value Value shown is typical Capacitors may be omitted or resistors jumpered Screwdriver adjustment Panel control Encloses front panel designation pc el Encloses rear panel designation Circuit assembly borderline Other assembly borderline line with arrows indicates path and direction of main signal dashed line with arrows indicates path and direction of main feedback Wiper moves toward CW with clockwise rotation of control as viewed from shaft or knob Numbered test point Measurement terminal provided Lettered Test Point No measurement terminal provided Encloses wire color code Code used MIL STD 681 is the same as the resistor color code First number identifies the base color second number the wider stripe and the third number identifies the narrower stripe e g 947 denotes white base yellow wide stripe violet narrow stripe harmonic number Ist LO fundamental Ist LO above or below 1st IF 550 MHz Ist IF no asterisk 2050 MHz Ist IF Letter off page connection Number Service Sheet location for off page co
102. n this Manual Changes Supplement Page 8 21 Figure 8 17 Service Sheet 4 Add capacitor C4 2 2 uF from A3UI pin 4 to signal ground Show positive side of capacitor connected to signal ground Page 8 23 Service Sheet 5 Replace with Figure 8 18A contained in this Manual Changes Supplement Page 8 23 Figure 8 19 Service Sheet 5 Add capacitor C7 2 2 uF from A2U2 pin 7 to signal ground Show positive side of capacitor connected to pin 7 Page 8 25 Figure 8 20 Service Sheet 6 Replace with Figure 8 20A contained in this Manual Changes Supplement Figure 8 21 Service Sheet 6 Add A2R36 and 2 8 as shown in partial schematic Figure 1 TM 11 6625 2781 14 6 CHANGE Cont d Figure 1 Partial Schematic of Figure 8 10 P 0 Change 1 CHANGE 2 DELETED CHANGE 3 DELETED CHANGE 4 Figure 8 10 Service Sheet 2 Change part number of A1U1 U2 and U5 to 1826 0261 preferred replacement Page 8 19 Figure 8 15 Service Sheet 3 Change part number of A1U3 U4 and U6 to 1826 0261 preferred replacement Page 8 21 Service Sheet 4 Change part number of A3UI to 1826 0261 preferred replacement Service Sheet 5 Change part number of A2U2 and U3 to 1826 0261 preferred replacement E 3 TM 11 6625 2781 14 6 Figure 8 9A A1 Predriver Assembly of 8445B Except Option 003 Change 1 TM 11 6625 2781 14 6 j Figure 8 13A Al Predriver Assembly of 8445B Option 003 Change 1
103. nce Chart e pi E bifference Data Sheets E 1 ILLUSTRATIONS Figure Page Figure Page 1 1 Model8445B and Accessories ee 1 0 82 Examples of Diode and Transistor 2 Serial Number Plate 2 2 LI Marking Methods 3 RF Interconnect Cable r6 ER Operational Amplifier Eduvalent Cit 8 8 me Line Voltage Selection L23 8 41 View of 8445B With Option 002 Panel Power Cable HP Part Numbers Versus Mains Plugs Available 2 2 Preparation for Rack Mounting 2 3 Spectrum Analyzer Tuning Curves and Responses E 3 2 3 2 Typical 3 dB Yig Filter Passband Display at 4 GHz and with a 10 MHz DIV sweep 8445B Controls Connectors and Indicators 3 4 Low Pass Filter Operation 10 MHz to 1 8 GHz 3 5 1 8 to 18 GHz YIG Tuned Filter Operation 3 6 Power Lamp Replacement PEN 53 13 41 Out of Band Rejection Test Setup 4 3 4 2 Insertion Loss Test Setup Dc 1 8 GHz 4 5 Insertion Loss Test Setup 1 8 18 GHz 4 7 YIG Filter Signal Compression Test Setup 4 10 Power Supply Adjustment Test Setup 52 5 2 Pre Driver Adjustment Test Setup 5 4 YIG Driver Adjustment Test Setup 577 5 4 Digital Panel Meter Adjustment Test Setup 5 9 Remote Amplifier Adjustment Test Setup Figure 5 3 PIOCHANGEC 72 Partial Schematic correction for Service Sheet 4 P O CHANGE C 7 4 7 31 Partial schematic co
104. ncludes interconnections for a Stan dard Model incorporating Options 002 003 and 004 malfunction in the Preselector or interconnecting cable can af fect operation of the Spectrum analyzer or a malfunction in the Spectrum Analyzer can affect Preselector operation Before trou bleshooting either instrument make sure the analyzer is operating correctly If the Preselector does not appear to function properly when connected to the Spectrum Analyzer take the following pre liminary corrective steps Remove interconnect cable replace firmly and lock into position Remove IF and RF Sections decouple from each other then recouple carefuliy Mate sections into main frame firmly and lock into position Make sure the 102 120 220 240 V power module printed circuit card is in the proper posi tion for the line voltage being used If proper operation does not now result a logical trouble isolation procedure should be employed Usually malfunction isolation should utilize the opera tion capability of the Preselector as far as possible Preselectors can be checked with the 2nd LO OUTPUT of the 8555A and har monics of this 1 5 GHz signal Units may be checked by remotely tuning the Preselector with a positive dc voltage of 1 GHz V applied to the REMOTE input Units with manual controls can be switched to MANUAL operating mode to tune them over the same range with front panel controls simple check for normal test point voltages may quick
105. ncy display or with an incorrect display To correct for a malfunction in the DPM circuitry use the following procedure E with the 8555A RF Section operating and coupled to the 8445B set the 8555A to BAND n 1 550 GHz and tune FREQUENCY to zero GHz Check for 7 5 V from AITP3 to ground A3TP2 With FREQUENCY tuned to 2 GHz check for 15 volts at Lack of these voltages indicates a malfunction in the 8555A RF Section or in the cabling between the 8555A and the 8445B If these voltages are obtained repeat the zero GHz check Indication should be zero volts reading at 8 Then set to BAND n 4 with FREQUENCY tuned to 18 450 GHz for a reading of 18 000 volts If these voltages are not obtained the malfunction is in the DPM Predriver Refer to Troubleshooting Procedure for Service Sheet 2 or Predriver Adjustment Paragraph 5 9 If voltages are correct incorrect frequency displays indicate malfunction in the digital panel meter itself Refer to Operating and Service Manual for the Model 34740A Measurement System part of the Option 003 Manual Supplement H If display voltage is present at 1 8 but not at input to the DPM orifrelay K11 does not close or open check for Band Code C voltages when switching between BAND 4 and BAND 6 Check for an open or shorted Q7 Q8 or K11 relay coil Figure 8 I1 Top View of 8445B With Option 003 Including Digital Display 7 TOP VIEW A 1003
106. nd Driver circuitry are 11 6625 2781 14 6 retained on the A2 Power Supply assembly for pos sible future use 3 OPTION 003 MODELS When Option 003 is ordered the Al Predriver shown shaded in Figure 8 5 is replaced with one containing both the shaded and unshaded circuits In addition a complete digial panel meter circuit is mounted behind a window on the front panel of the Preselector Figure 8 11 The 8555A supplies a 7 5 V to 15 V TUNE voltage from its YIG tuned LO Driver This voltge is processed in a manner similar to the SWEEP TUNE voltge in the Stan dard Model except that the output of the DPM sec tion Summing Amplifier converts the TUNE vol tage to 1 025 GHz level fed to the DPM The digital meter is a voltmeter with a resistive voltage divider input to convert the 1 025 GHz V to a 1GHzN level When the 8555A is tuned to a fre quency of 3 GHz for example the Summing Amp lifier output is 3 x 0 976 or 2 927 V resulting in a display reading of 3 000 GHz If the Preselector is tracking properly the frequency being displayed is also the center frequency of the YIG filter pass band 4 OPTION 002 MODELS Option 002 adds a MODE switch with AUTOmatic REMOTE LOW PASS and MANUAL positions plus COARSE and FINE manual tuning controls on the front panel of the Preselector Figure 8 4 and unshaded circuitry of Figure 8 6 In the AUTO posi tion the Preselector operates as a Standard Model In the REMOTE pos
107. nnect input cable when using REMOTE input to tune YIG filter Figure 3 3 8445B Controls Connectors and Indicators 3 of 3 Model 8445B 11 6625 2781 14 6 OPERATOR S CHECKS USING LOW PASS FILTER FRONT VIEW dni tiir ori EE BERE Ta Figure 3 4 Low Pass Filter Operation 10 MHz to 1 8 GHz 1 of 3 TM 11 6625 2781 14 6 Model 8445B OPERATOR S CHECKS USING LOW PASS FILTER Check that the Line Voltage Selection Card is positioned to correspond to the available line voltage Refer to the information on Line Voltage Selection in Section 11 Connect interconnect cable beween AUX B output on Spectrum Analyzer Display Section and TUNING CONTROL SPECTRUM ANALYZER input on Preselector Connect Preselector and Spectrum Analyzer to line voltage source and apply power Perform Spectrum Analyzer Operational Adjustments ir Section III of Spectrum Analyzer RF Section 8555A Operating and Service Manual NOTE The information below does not apply to Automatic Preselectors with Op tion 004 which have no low pass filters Adjustments for such instruments are outlined in Set analyzer LOG LINEAR switch to LINEAR and rotate LOG REF LEVEL control until 1 mV DIV is matched with the lighted index lamp Connect Analyzer CAL OUTPUT to INPUT of Preselector Connect rigid coaxial cable between Preselector OUTPUT and Analyzer INPUT Note and record low pass filter insertion loss at
108. nnection Chassis ground Assembly ground TM 11 6625 2781 14 6 Model 8445B Table 8 3 Etched Circuit Soldering Equipment Specification Item Recommended Soldering Soldering tip De soldering aid Soldering Unsoldering Soldering Unsoldering To remove molten solder from connection Wattage rating 472 56 Tip Temp 850 900 degrees Shape pointed Ungar No 776 handle with Ungar No 4037 Heating Unit Ungar No PL111 Suction device Soldapult by Edsyn Co Arleta California Resin flux Remove excess flux from soldered area before ap plication of protective coating Must not dissolve etched base board material or conductor bonding agent Freon Aceton Lacquer Thinner Isopropyl Alcohol 10096 dry Component replacement Circuit board repair Wiring Resin flux core high tin content 60 40 tin lead 18 gauge SWG preferred Protective coating Contamination corro sion protection Good electrical insulation corrosion prevention pro perti es Silicone Resin such as GE DRI FILM 88 For working on etched boards for general purpose work use Ungar No 1237 Heating Unit 37 5W tip temperature of 750 800 degrees and Ungar No PL113 1 8 inch chisel tip General Electric Co Silicone Products Dept Waterford New York U S A 8 19 Component Replacement holes sharp lead ends may damage the plated through conductor
109. nput Figure 1 3 The power cable supplied with the instrument is selected at time of shipment Selection is based on shipping destination Figure 2 2 illustrates the dif ferent power cable connectors that are currently available TM 11 6625 2781 14 6 1 40 EQUIPMENT REQUIRED BUT NOT SUPPLIED 1 41 The Automatic Preselector is intended for use with the 8555A Spectrum Analyzer System This includes an 8555A RF Section an 8552 series IF Section and a 140 or 141 series Display Section 1 42 EQUIPMENT AVAILABLE 1 43 The rigid RF Interconnect cable used to cou ple a Preselector to a Spectrum Analyzer is illus trated in Figure 1 3 Standard Preselectors are made to operate above the Spectrum Analyzer The possible mounting configurations connector types dimensions and part numbers are indicated ir Table 1 4 For information regarding RF Interconnect ca bles used when the Preselector is mounted BELOW the Spectrum Analyzer contact your local Hewlett Packard Sales Office Rack Mounting Kit is available to install the instru ment In a 19 inch rack Rack Mounting Kits may be obtained through your nearest Hewlett Packard Office by ordering HP Part Number 5060 8739 Table 1 3 Accessories Supplied HP Part Number Line Power Cable 116701 RF Interconnec Cable 08445 60007 Interconnect Cable 2110 0012 Fuse 5060 8543 J oining Bracket Kit See paragraph 2210 end Figure 2 2 5 and Figure 1 3 item not suppli
110. nter Signal Generator signal on CRT display 10 Reduce Spectrum Analyzer BANDWIDTH to 30 kHz and SCAN WIDTH PER DIVISION to 0 5 MHz Center signal on CRT display with FINE TUNE control 4 4 Model 8445B TM 11 6625 2781 14 6 PERFORMANCE TESTS 4 17 OUT OF BAND REJECTION TEST Cont d 1l Reconnect Signal Generator output to Preselector input and interconnect cable to Spectrum Analyzer input and Prelector output 12 Note and record signal level Signal should be at least 70 dB below the reference level set in step 5 Out of Band dB 4 18 LOW PASS FILTER INSERTION LOSS TEST Omit for Instruments with Option 004 SPECIFICATION Low Pass Filter Insertion Loss Dc 1 8 GHz 2 5 dB At 2 05 GHz gt 50 dB DESCRIPTION Insertion loss is measured at the high end of the filter s operating range 1 8 GHz by applying a known input power level and measuring the output power level Filter rejection at 2 05 GHz is measured in the same manner 8445B SIGNAL GENERATOR W3 CABLE TO AUX B CONNECTORS AT BACK Figure 4 2 Insertion Loss Test Seup Dc 1 8 GHz EQUIPMENT Spectrum HP 8555A 8552 141T Signal Generator ost udo kel saves ia a eet a ULIS HP 8616A 4 5 TM 11 6625 2781 14 6 PERFORMANCE TESTS 4 18 LOW PASS FILTER INSERTION LOSS TEST Cont d 1 4 6 Connect test setup as indicated in Figure 4 2 and make the following co
111. ntrol settings PRESELECTOR ANALYZER LINE OFF ON ON BAND L M n 1 I F 2 05GHz FREQUENCY S ics vie aM Sp 1 8 GHz BANDWIDTH yras pis acd RC CR RNC rt 300 kHz SCAN WIDTH PER DIVISION 10 MHZ INPUT ATTENUATION ise sasa i bake cei Rer tee eere s 10 dB BASE LINE CLIPPER j pam Ed d kaq pa 9 o dock SCAN TIME PER 1 10 MILLISECONDS LOG 424559 kai race ed REA eh di kisiki 20 dBm LOGLLINEAR asss ERROR RE RR TEE ERE EEG CRY E RERO 10 dB LOG VIDEO FILTER secet ei rib d ce bed a n at te a 10 kHz SCAN MODE 5 ctincrneGitivees Gea AURA E RR ee RETE VERI hes Chae aber INT SCAN TRIGGER ia acida aote Man po cta Rap pO a fra pola AUTO POWER utasa tei eben es ON SIGNAL GENERATOR SI Aem rcc On pie pedis EM On FREQUENCY Ed 1800 MHz ATTENUATION eee ce eer arae sol eer eee 10 dB Connect Signal Generator output to Preselector INPUT Connect Preselector OUTPUT to Analyzer INPUT Note and record insertion loss Insertion loss should not exceed 2
112. oltage drop across R19 is approximately 1 volt With the heater circuit open the voltage drop should be less than 0 1 volt When operating normally the voltage across R20 is approximately 1 volt less than that across VR6 and the voltage across R18 is 0 6 volt Variations of any of these voltages should indicate which component is faulty 8 20 Model 8445B TM 11 6625 2781 14 6 PIO A5 PIO A2 POWER INTERCONNECT PIO M YIG PIO A5 INTERCONNECT BOARD YIG DRIVER ASSY 08445 60103 SUPPLY ASSY BOARD FILTER ASSY A3 OUTPUT i a 10 F na W TaA 110 DRIVER vr OFFSET SUPPLY DRIVER AMPL tA l I 19 5V NE i 24 a R14 l 0 49 5 80 lt 31 6K x pel 8 oe TOP VIEW 04 f SUMMING 9Vde REFERENCE o g POWER GROUND se 1 R SIGNAL GROUND 2 lt ee 28 COURSE 19 5V TRACKING R10 XA5 BOTTOM VIEW YIG DRIVER 110 EFHJIJKLMNPRS B C D 4 1234567 8 9101112131415 FREQ OFFSET REFERENCE DESIGNATIONS PREFIX PREFIX R1 2 16 GHz ADJ OPTION 003 ONLY gt REFERENCE DESIGNATIONS WITHIN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER e g OF ASSEMBLY 1 15 AIRI DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN NOTES 1
113. olts 18 GHz Note Items in italics and underlined are used in Option 003 instruments Factory selected component 5 1 TM 11 6625 2781 14 6 5 4 Each adjustment procedure contains a list of test equipment for that particular test Table 1 4 contains a list of test equipment and accessories re quired in the adjustment procedures In addition the table contains the required minimum specifications and a suggested manufacturer s model number 5 5 FACTORY SELECTED COMPONENTS 5 6 Table 5 1 contains a list of adjustable controls and factory selected components by reference desig nation name and function Approximate location of a component can be determined by its assembly letter number as A1 designation preceding its component number Factory selected components are designated by an asterisk in the table and on the schematic diagrams if Section VIII 5 7 RELATED ADJUSTMENTS 5 8 The adjustment procedures of this section are arranged in numerical order For best results this order should be followed All data taken during ad Model 8445B justments should be recorded in the spaces provided Comparison of initial data with that taken during subsequent periodic adjustments assists in preven tive maintenance and troubleshooting 5 9 LOCATION OF ADJUSTMENTS 5 10 The locations of all components used in mak ing adjustment tests are illustrated on photographs adjacent to related Service Sheets or on
114. or 1 GHz frequency separation DC POWER SUPPLY SIGNAL GENERATOR TO REMOTE BNC OUTPUT WI RF CABLE SPECTRUM ANALYZER Figure 4 1 Out of Band Reection Test Setup EQUIPMENT Spectrum HP 8555A 8552 141T Signal Generato cii L L ul Ce pu sae dao HP 8616A Power 5 ede Boe ae Orbe Ro P EA de HP 6205B Coaxial Cable BNC to alligator lt HP10501A Required for Preselectors without manual controls 1 Connect test setup as indicated in Figure 41 and make the following control settings PRESELECTOR without manual controls LINE OFF ON zione e ayaq e aan unqun xt b e oy ORI e ON Interconnect able oii iid ues cea Xon ko REP ed Disconnected PRESELECTOR with manual controls EINE OBRE ON deu a ce Sh d ee ace ict EX eco Pix Ec ec E dede ion etg ON MODE gd pr MANUAL MANUAL TUNE COARSE 3GHz MANUAL 0 GHZ 4 3 11 6625 2781 14 6 Model 8445B PERFORMANCE TESTS 4 17 OUT OF BAND REJECTION TEST Cont d POWER SUPPLY Output Voltage zu l u Lau en a RR EROR OD RUE 3Vdc ANALYZER BAND maa tuia bct decl cat n 2 FREQUENCY 5 gee utes pleure T t Ete Th
115. or 240 V dosest to the voltage you measured in step a Line voltage must be within 5 or 1096 of the voltage setting c Make sure the correct fuse is installed in the fuse holder The required fuse rating for each line voltage selection is indicated at the power module d Connect the ac power cord to the instru ment ac power receptacle 2 10 Power Cable 2 11 In accordance with international safety stan dards this instrument is equipped with a three wire power cable When connected to an appropriate power line outlet this cable grounds the instru ment cabinet Figure 2 2 shows the styles of mains plugs available on power cables supplied with HP instruments The numbers under the plugs are part numbers for complete power cables WARNING The protection provided by grounding the instrument cabinet may be lost if any power cable other than the 3 pronged type is used to couple the ac line voltage to the instrument Figure 2 2 Power Cable HP Part Numbers Versus Mains Plugs Available Model 8445B 2 12 Mating Connectors 2 13 A list of possible connectors on the front and rear panels of the Model 8445B is given i 2 1 2 14 Operating Environment 2 15 The operating environment should be within the following limitations to 55 C Humidity lt 95 relative Altitude 15 000 feet 2 16 A forced air cooling system is used to main
116. periodically It is recommended that it be checked every three months and if necessary washed in warm water and detergent After washing allow the filter to dry for a few minutes before reinstallation 3 26 Fan 3 27 The fan in this instrument is a self lubricating unit and does not require maintenance 3 28 Lamp Replacement 3 29 The lamp is contained in the white plastic lens which doubles as a pushbutton for the LINE switch When the switch is ON the lamp should be illuminated illustrates how to remove and install thelamp Thelamp DS1 maybe ordered under HP part number 2140 0244 3 3 Model 8445B TM 11 663 2781 14 6 i Y Figure 3 3 8445B Controls Connectors and Indicators 1 of 3 Model 8445B TM 11 6625 2781 14 6 8445B FRONT PANEL FEATURES LINE ON OFF Controls primary power Light glows when switch is energized Type A1H bulb PRESELECTOR INSERTION LOSS Chart Indicates insertion loss versus fre quency Calibration chart extrapolated from point to point measurements of YIG filter inser tion loss FREQ OFFSET control adjusted for minimum insertion loss at each test point Dur ing power level measurement Spectrum OUTPUT coaxial connector normally Analyzer LOG REF LEVEL Vernier control be adjusted to compensate for the indicated inser tion loss FREQ OFFSET Adjusts YIG driver to corn O pensate for offset in YIG filter tuning due to re si
117. propriate item in section column 6 b Remarks This column provides the required ex planatory information necessary to clarify items appearing i TM 11 6625 2781 14 6 SECTION MAINTENANCE ALLOCATION CHART FOR FILTER VARIABLE F 1hi U 8 445B 2 3 N GROUP COMPONENT ASSEMBLY MAINTENANCE NUMBER FUNCTION FILTER VARIABLE F 12414 U HP 8445B Inspect Test Service Align Adjust Install Replace Repair Repair Overhaul ZIRCUIT CARD ASSEMBLY PREDRIVER Al Inspect Adjust Replace Repair ZIRCUIT CARD ASSEMBLY POWER SUPPLY A2 Inspect Adjust Replace Repair ZIRCUIT CARD ASSEMBLY YIG DRIVER Inspect Adjust Replace Repair IG FILTER Inspect Replace Repair D 4 INTENANCE CATEGORY oo Mw 4 F H oooo A Ew oo Ww QU FU 0 3 0 4 2h Ow ow ou 6 REMARKS OOL OR TES EQUIPMENT REF CODE MAINTENANCE CATEGORY SECTION TOOL AND TEST EQUIPMENT REQUIREMENTS FOR FILTER VARIABLE F 1h1h U HP 8445B NOMENCLATURE TEST SET METER TS 682 GSM 1 VOLTMETER ELECTRONIC AN URM 145 3ENERATOR SIGNAL AN URM 127 JSCILLOSCOPE AN USM 281C TRANSISTOR TEST SET TS 1836C U MULTIMETER ME 26D U TOOLS AND TEST EQUIPMENT USED BY THE TECHNICIAN FOR THE ASSIGNED MISSION TM 11 6625 2781 14 6 IATIONAL NATO STOCK NUMBER 625 00 669 0747 625 00 973 3986 625 00 783 5965 625 00 106 9622 625 00 159 2263 62
118. requires test equipment has a test setup draw ing and a list of required equipment Step 1 of each procedure gives control settings required for that particular test 4 14 Required minimum specifications for test equipment are detailed ir Table 1 8 If substitute test equipment is used it must meet the specifica tions listed in order to performance test the Pre selector 4 15 ABBREVIATED PERFORMANCE TEST 4 16 To assure that the Preselector is performing properly without testing all of the specifications listed in the following procedure is sug gested as an abbreviated performance test a Perform OPERATORS CHECK in Figure 3 4 and Figure 3 5 as applicable b Perform only the following performance tests 11 Paragraph 4 18 Low Pass Filter Inser tion Loss Test 2 Paragraph 4 19 YIG Filter Insertion Loss Test PERFORMANCE TESTS 4 17 OUT OF BAND REJECTION TEST SPECIFICATION For YIG tuned filter 1 GHz from center of passband gt 70 dB 4 2 Model 8445B TM 11 6625 2781 14 6 PERFORMANCE TESTS 4 17 OUT OF BAND REJECTION TEST Cont d DESCRIPTION The YIG filter is tuned to a GHz fixed frequency either manually or remotely by a 3 Vdc to the REMOTE input A 3 GHz signal is applied through the filter and the power output level measured The signal source is then shifted 1 GHz and the power output level is again measured The difference between the two power levels is the out of band rejection f
119. riel Readiness Command ATTN DRSEL ME MQ Fort Mon mouth NJ 07703 A reply will be furnished direct to you 0 7 Items Comprising an Operable Equipment Filter Variable F 1414 U comprises an operable equipment 0 1 11 6625 2781 14 6 Mode18445B RF INTERCONNECT CABLE LINE POWER CABLE E See ACCESSORIES SUPPLIED in Table 1 3 for part number information Figure 1 1 Model 8445B and Accessories Supplied 1 0 Model 8445B 11 6625 2781 14 6 SECTION 1 GENERAL 1 1 INTRODUCTION 1 2 This manual contains all information re quired to install operate test adjust and service the Hewlett P ackard Model 8445B Automatic Preselec tor This section covers instrument identification description options accessories specifications and other basic information 1 3 Figure 1 1 shows the Hewlett Packard Model 8445B Automatic Preselector with Option 002 manual tuning controls and Option 003 digital readout of center frequency 1 4 The various sections in this manual provide information as follows SECTION INSTALLATION provides in formation relative to incoming inspection power requirements mounting packing and shipping etc SECTION OPERATION provides infor mation relative to operating the instrument SECTION IV PERFORMANCE TESTS pro vides information required to ascertain that instrument is performing in accordance with published specifications SECTION V ADJUSTMEN
120. rop less than 10 dB on CRT YES Reconnect cable to 84458 Shift to BAND 4 Tune to 15 GHz Set 8555A INPUT ATTENUATION to 10 dB Is 10th harmonic of 2nd L visible when FREQ OFFSET is varied If voltage at ATTP7 equal to 0 976 of the FRE QUENCY setting of the 85554 dial YES Is voltage at A3TP4 equal to 0 976 of the FRE QUENCY setting af the 8555A dial YES Using a clip on ammeter does the YIG tuning coll NO current read 26 mA GHz when the 85554 FRE QUENCY dial is varied YES If loss gt 10 dB refer to YtG FILTER INSERTION LOSS test paragraph 4 19 ro determine true loss Refer tu paragraph 5 13 for YIG DRIVER ABJUSTMENT Refer to SS for YIG Predriver Troubleshooting Refer ta 555 for Automatic Switchiny Control Troubleshooting Is YIG circuit fuse A3F1 open Check for YIG cail to graund short Thea refer 10 594 for troubleshooting of YIG driver circuits CAUTION Set ohmmeter ta 1000X scale when checking fine wire coil af YIG filter NO Remove rigid cables from YIG Is there continuity to ground at input and output connectors Check for opens or shorts in rigid cables coaxial switch contacts and INPUT and GUTPUT connectors Replace faulty components With ohmmeter is there continuity across coil Replace YIG Filter YES Refer to SS4 for troubleshooting of YIG Driver Circuits Replace YIG filter NO 1i 6625 27 51 14 6 MANUAL
121. rouble isolation procedures 5 12 YIG OR DPM PRE DRIVER ADJUSTMENT REFERENCE Service Sheets 2 3 and 4 TM 11 6625 2781 14 6 Model 8445B ADJUSTMENTS 5 12 YIG OR DPM PRE DRIVER ADJUSTMENT Cont d DESCRIPTION With the Preselector connected to the Spectrum Analyzer the Predriver Assembly A6 is checked and adjusted for an output voltage that tracks the tuned frequency of the Spectrum Analyzer All operational amplifiers amplifiers are adjusted for balance and checked for correct gain Voltage offset is adjusted to correspond to the 550 MHz or 2050 MHz IF of the Spectrum Analyzer NOTE Instructions in italics and underlined refer to Option 003 instruments only SPECTRUM DIGITAL MULTIFUNCTION ANALYZER VOLTMETER UNIT TO 1 2 amp A3TP2 AUXILLARY B INTERCONNECT CABLE Figure 5 2 PreDriver Adjustment Test Seup EQUIPMENT Spectrum Analyzer em HP 8555A 8552 141T Digital Voltmeter with Multifunction Unit HP 3480B 3484A NOTE For Option 003 instruments the A7 Digital Display Assembly must be removed prior to any Pre Driver adjustments Remove A7 by disconnecting the input cable on the rear of the assembly and by removing two screws from the mounting bracket adjacent to the P1 marking on the main deck 1 Connect test setup as shown in 2 Apply power to both Preselector and Spectrum Analyzer Allow at least 30 minutes for equipment to stabilize 5 4 Model 8445B TM 11 6625 27
122. rrection for Service Sheet 5 P O CHANGE 74 8 l Transistor Characteristics and Biasing 8 8 iv Switches and Controls 8 10 Block Diagram of Standard 8445B With Option 003 Circuits Unshaded 8 11 8 6 Block Diagram of 8445B With Option 002 Circuits Unshaded 8 11 8 7 Troubleshooting Flow Diagram 8 13 8 8 Comprehensive Block Diagram Including Options 002 and 003 8 15 Al Predriver Assembly of 8445B Except Option 003 L 8 17 8 10 YIG Predriver Schematic Diagram 8 17 Top View of 8445B With Option 003 Including Digital Display A7 8 18 8 12 Top View of 8445B Option 003 With 7 Removed 8 13 Al Predriver Assembly of 8445B Option 003 8 18 8 14 A7 Display Board See Option 003 Supplement For Details A7 8445B 8 15 DPM Predriver Schematic Diagram 8 16 YIG Driver Assembly L 8 21 8 17 P O YIG Driver Schematic Diagram 8 21 A2 Power Supply and Filter Switching Assembly 8 23 8 19 Remote and Manual Control Switching Circuit Schematic Diagram 8 23 8 20 A2 Power Supply and Filter Switching Assembly 8 21 Power Supply and Power Line Module Schematic Diagram 8 23 8 22 lAdjustment Controls 827 8 23 Option 003 Al Adjustment Controls 108271 8 24 Over all Schematic Diagram L 8 29 Model 8445B Table
123. rting insertion loss values for the additional frequencies listed 3 Send a copy of the data induding Option number of instrument if any to your local Hewlett Packard office Arrangements will be made with the factory to produce a replacement front panel Insertion Loss Chart The Insertion Loss Chart curve for the original YIG filter was developed from data taken at these same frequencies Table 5 2 Insertion Loss Table Frequency Loss Frequency GHz dB GHz E Model 8445B 11 6625 2781 14 6 SECTION VII MANUAL CHANGES 7 1 INTRODUCTION 7 2 This section contains information for adapt ing this manual to instruments for which the con tent does not apply directly 7 3 To adapt this manual to your instrument re fer to Table 7 1 make all of the manual changes listed opposite your instrument serial number Perform these changes in the sequence listed 7 4 If your instrument serial number is not listed on the title page of this manual or irj Table 7 1 below it maybe documented in a yellow MAN UAL CHANGES supplement For additional im portant information about serial number coverage refer to INSTRUMENTS COVERED BY MANUAL in Section Table 7 1 Serial Number Change History Sarial Prefix or Number Make Manual Changes 7 5 MANUAL CHANGE INSTRUCTIONS CHANGE A Page 8 19 Figure 8 8 Service Sheet 4 Change A3R6 to 100 ohms CHANGE B Page 8 19 Service Sheet
124. s listed Model 8445B 11 6625 2781 14 6 Table 1 5 Test Equipment and Accessories 1 of 2 mm Minumum Specifications Frequency Comb Frequency markers spaced 1 10 100 MHz apart Generator usable to 8 GHz Frequency Accuracy 0 01 Output Amplitude gt 40 dBm to 2 GHz Suggested Model HP 8406A Comb Generator Frequency Range 1 8 4 0 GHz Frequency Accuracy 1 Output Amplitude gt 5 dBm Output Impedance 50 ohms Signal Generator HP 8616A Signal Generator Sweep Oscillator HP 8620A Sweep Oscil lator with 86290A RF Unit Frequency Range 2 0 18 GHz Output Amplitude gt 5 dBm Output Impedance 50 ohms Digital Voltmeter Voltage Accuracy 0 01 of reading 0 01 of range Resolution 1 mV 10 volts Overrange 50 Input Impedance 10 megohms HP 3480B Digital Multimeter with HP 3484A Multi Function Unit Frequency Range DC to 50 MHz Time Base 1 us div to 10 ms div Time Base Accuracy 3 Dual Channel Alternate Operation Ac or de Coupling External Sweep Mode Voltage Accuracy 3 Sensitivity 0 005 V div HP 180A with HP 1801A Vertical Amplifier and HP 1821A Horizontal Amplifier HP 10004 10 1 Divider Probes 2 Oscilloscope HP 435A Power Meter with HP 8481A Power Sensor Power Meter Frequency Range 0 01 18 0 GHz Accurac
125. tenance allocation chart Subcolumns of column 4 are as follows C Operator Crew O Organizational F Direct Support H General Support D Depot e Column 5 Tools and Equipment Column 5 specifies by code those common tool sets not in dividual tools and special tools test and support equipment required to perform the designated func tion f Column 6 Remarks Column 6 contains an alphabetic code which leads to the remark in section IV Remarks which is pertinent to the item opposite the particular code D 4 Tool and Test Equipment Requirements See III Tool or Test Equipment Reference Code The numbers in this column coincide with the numbers used in the tools and equipment column of the MAC The numbers indicate the applicable tool or test equipment for the maintenance functions b Maintenance Category The codes in this column indicate the maintenance category allocated the tool or test equipment c Nomenclature This column lists the noun name and nomenclature of the tools and test equipment required to perform the maintenance functions d National NATO Stock Number This column lists the National NATO stock number of the specific tool or test equipment e Tool Number This column lists the manufac turer s part number of the tool followed by the Federal Supply Code for manufacturers 5 digit in parentheses D 5 Remarks See IV a Reference Code This code refers to the ap
126. th the serial number prefix es listed under SER IAL NUMBERS on the title page 1 21 An instrument manufactured after the printing of this manual may have a serial number prefix that is not listed on the title page This un listed serial number prefix indicates the instrument is different from those described in this manual The manual for this newer instrument is accompanied by a yellow Manual Changes supplement This sup plement contains change information which tells you how to adapt the manual to the newer instru ment 1 22 In addition to change information the sup plement may contain information for correcting er rors in the manual To keep this manual as current and accurate as possible Hewlett Packard recom mends that you periodically request the latest Man ual Changes supplement The supplement for this manual is identified with this manual s print date and part number both of which appear on the man ual title page Complimentary copies of the supple ment are available from Hewlett Packard 1 3 TM 11 6625 2781 14 6 1 23 Forinformation concerning a serial number prefix that is not listed on the title page or in the Manual Changes supplement contact your nearest Hewlett Packard office Figure 1 2 Serial Number Plate 1 24 Option 003 Instruments Only 1 25 When an 8445B Option 003 instrument is ordered paragraph 1 B3 this manual an Op tion 003 Supplement and an A7 Digital Panel Meter
127. the Remote Amplifier output is fed to the YIG Driver input through relay contacts 1 and 6 Option 003 When a digital panel meter is added A3K1 connects the DPM Predriver output to the DPM drive circuitry as long as A3K1 is energized In Standard Models the jumper between TB1 terminals 5 and 7 feeds the DPM In Option 002 models this jumper is removed to allow feed through the MODE switch to the DPM TROUBLESHOOTING PROCEDURE When a malfunction has been isolated to the Coaxial Switch Driver the Manual Control Buffer Amplifier the Remote Control Buffer Amplifier or the Automa tic Switching Control circuit perform the following test procedure Connect the Preselector to the Analyzer apply power and allow instruments to stabilize Warmup time required only for measurements associated with amplifiers A2U2 and A2U3 Make all voltage measurements in reference to A3TP2 common ground point EQUIPMENT REQUIRED 8555A Spectrum HP 8555A 8552 140 Digital HP 3480A Power S pply iiis bee eei x CR Ad bee hated HP 6205B TM 11 6625 2781 14 6 Model 8445B SWITCH DRIVER Set Analyzer controls as follows BAND no AF 550 GHz FREQUENCY to 1 5 GHz and SCAN WIDTH to ZERO On Preselectors with Option 002 set MODE switch to AUTO Connect voltmeter to test point A Shift BAND Lever on the 8555A RF Section to select
128. the last fold out page in Section VIII Figures 8 20 and 8 21 Table amp Tllists all of the controls used in making adjustment tests as well as all factory selected com ponents WARNING Line voltage is always present on termi nals induding the power input connector fuse holder power switch power trans former etc addition when the instru ment is on energy available at many points may result in personal injury or death when contacted ADJUSTMENTS 5 11 POWER SUPPLIES ADJUSTMENT REFERENCE Service Sheets 4 and 6 DESCRIPTION Power supplies in the Preselector provide regulated outputs of 19 5 28 and 23 volts and an unregulated output of 40 volts Only the 19 5 voit supply is adjustable These checks verify proper operation of the power supplies DIGITAL VOLTMETER MULTIFUNCTION UNIT TO A3TP2 amp A TP1 VARIABLE VOLTAGE TRANSFORMER AC VOLTMETER TO REAR PANEL LINE INPUT TO Tl TERMINALS 1 amp 3 Figure 5 1 Power Supply Adjustment Test Seup Model 8445B TM 11 6625 2781 14 6 ADJUSTMENTS 5 11 POWER SUPPLIES ADJUSTMENT EQUIPMENT Digital Voltmeter with Multifunction Unit HP 3480B 3484A Dub n cB 427 Variable Voltage General Radio W5MT3A Connect test setup as indicated in Figure 5 1 Assure line voltage Po
129. tion is indicated see Paragraph 8 30 for Oper ational Amplifier Troubleshooting Procedure Model 64405 IM 11 6625 2781 14 6 5 BOTTOM VIEW ABCDEFHJKLMNPRS 23456782911120DMI5 SPECTRUM ANALYZER PO 5 INTERCONNECT BOARD AlYIG PREDRIVER ASSY 0845 60101 ALSO P O Al DPM PREDRIVER ASSY FOR OPTION 003 10845 60102 _ _ _ Ico RU RP R d EN 2 wv de os NEN e M e BUE NEN R 100 RF SECTION NK i we E pF 350 GHz 2 05 GHz NETW0RK lt R RB i R25 Xn 89 i I 117 5 AP 8 40 5 Tod i gi DEMNM MN i es nt ee ee J I 1 1 19 SV k5 1 2 5 1 8 Q1 6 9 10 LOGEC DECODERIRELAY DRIVERS TP1 2 5 7 1 2 5 1 4 NOTES 1 SEE SCHEMATIC DIAGRAM NOTES TABLE 8 3 2 THE OFF PAGE CONNECTIONS SERVICE SHEET 3 ARE APPLICABLE ONLY IF THE INSTRUMENT HAS OPTION 003 SW POWER GROUND SIGNAL GROUND REFERENCE DESIGNATIONS WITHIN OUTLINED T ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION CLUDES ASSEMBLY NUMBER e g OF ASSEMBLY e Dn I AIRI DESIGNATIONS OF OTHER COMPONENTS ARE ae 1 COMPLETE 45 SHOWN ee Figure 8 9 A1 Predriver Assembly of 8445B Except Option 003 Figure 8 10 YIG Predriver Schematic Diagram 8 11 I SERVIC
130. tor and the signal disappears from the CRT display j Select BAND 1 550 GHz Connect a 2 0 GHz 30 dBm signal to pre selector INPUT 1 Tune Spectrum Analyzer to center the 2 0 GHz signal on CRT display m Adjust Preselector FREQ OFFSET to peak the 2 0 GHz signal n Select BAND n 3 and connect a 12 GHz 30 dBm signal to Preselector input o Tune Spectrum Analyzer FREQUENCY con trol to center signal on CRT display p Adjust Preselector TRACKING control to maximize signal level on CRT display q Repeat steps j though p for optimum adjust ment 4 10 PERFORMANCE TESTS 4 11 The performance tests given in this section are suitable for incoming inspection troubleshoot ing or preventive maintenance During any perfor mance test all shields and connecting hardware must be in place The tests are designed to verify published instrument specifications Perform the tests in the order given and record data on test card and or in the data spaces provided in each test Model 8445B 4 12 The tests are arranged in the following order Paragraph Test Description Out of Band Rejection Low Pass Filter Insertion Loss YIG Filter Insertion Loss 4 20 Limiting Level Signal Compression 4 13 Each test is arranged so that the specification is written as it appears in Table 1 1 Specifications Next a description of the test and any special in structions or problem areas are included Each test that
131. truc tions for preparing the instrument to be mounted on a rack of 19 inch spacing Installation instructions med nin Model 8445B 11 6625 2781 14 6 Table 2 1 Modd 8445 Mating Connectors Connector Industry identification Alternate HP Part No Sources J1 INPUT Type N male connector UG 21G U Option 001 Type APC 7 connector Amphenol Bendix Specialty Connector 1250 0882 1250 1183 Amphenol Type N male connector UG 21G U Option 001 Type APC 7 connector J2 OUTPUT J4 REMOTE input J5 Interconnect cable connector TILT STAND Type BNC male connector UG 88 U R amp P Series 17 contact female connector FOOT RELEASE BUTTON LARGER NOTCH TRIM STRIP ADHESIVE BACKED FILLER STRIP BOTTOM COVER INSTRUCTIONS 1 REMOVE TILT STAND PLASTIC FEET AND TRIM STRIPS 2 ATTACH FILLER STRIP AND RACK MOUNTING FLANGES KEEPING LARGE NOTCH ON FLANGES TO INSTRUMENT BOTTOM Figure 2 3 Preparation for Rack Mounting Amphenol Bendix Specialty Connector 1250 088 1250 1183 Amphenol Amphenol Bendix Specialty Connector 1250 0256 1250 1286 2 23 MODIFICATIONS REQUIRED 2 24 Display Sections 2 25 HP Model 140T Display Sections with serial prefix 1105A and below HP Model 141T Display Sections with serial prefix 1047A and below all HP Model 140S 141S Display Sections and all HP Model 140 series Oscilloscope Mainframes requ
132. trument is tested against A list of typical operat ing characteristics is provided ir Table 1 2 They are included as additional information only they are not specifications 1 9 SAFETY CONSIDERATIONS 1 10 General 1 11 This is an International Electrotechnical Commission IEC Safety Class instrument de signed and tested according to IEC Publication 348 Safety Requirements for Electronic Measuring Apparatus It has been supplied in safe conditon 1 12 Operation 1 13 BEFORE APPLYING POWER make sure the ac input to the instrument is set for the available ac line voltage that the correct fuse is installed Figure 2 1 and that all normal safety precautions have been taken 1 14 Service 1 15 Although the instrument has been designed in accordance with international safety standards 1 1 TM 11 6625 2781 14 6 M ode18445B Table 1 1 8445B Specifications SPECIFICATIONS Frequency Range Dc to 1 8 GHz Low Pass Filter 1 8 to 18 GHz Tracking Filter Digital Frequency Readout Option 003 Resolution 1 MHz Accuracy 0 01 to 1 0 GHz 6 MHz 1 0 to 4 0 GHz 8 MHz 4 0 to 18 0 GHz 0 2 96 Insertion Loss Frequency De 1 8 GHz 2 05 GHz Low Pass Filter 1 8 12 GHz 12 18 GHz Tracking Filter YIG Low Pass Filter deleted with Option 004 Out of Band Rejection For YIG tuned filterl GHz from center of passband gt 70 dB Limiting Level gt 5 dBm Maxi
133. ts 12 o clock ANALYZER BAND an besa 2 FREQUENCY i ences ccr IR CER RICH US 4 0 GHz SCAN WIDTH PER DIVISION 24223 pida arra ede 10 MHZ INPUT ATTENUATION 35d 3 iR be t ri Re el keene hae Rc C lr Rat 10 dB BASE LINE CLIPPER vee tesa Abra ds Sed abd 9 o dock SCAN TIME PER DIVISION 54553 m ma ns 10 MILLISECONDS LOG REF LEVEL d TAREA 20dBm LOG LINEAR SWITCH 10 dB LOG VIDEO FILTER dA REL S qub E uid SCAN MODE ERREUR IER RR LACE a Q aaye atat INT SCAN TRIGGER qe Tc T AUTO POWER MERECE ON Connect BNC fitting of coaxial cable to REMOTE input on Preselector Connect center conductor of coaxial cable to terminal on Power Supply Connect outer conductor of coaxial cable to terminal on Power Supply Connect Sweep Oscillator RF Output to Spectrum Analyzer INPUT Model 8445B Reduce Spectrum Analyzer SCAN WIDTH PER DIVISION to 1 MHz Centersignal on CRT display with FREQUENCY control Model 8445B TM 11 6625 2781 14 6 PERFORMANCE TESTS 4 19 YIG FILTER INSERTION LOSS TEST Cont d 7 10 11 12 13 14 15 16 17 Set SIGNAL IDENTIFIER swith to ON Perform signal identification see
134. u Inches 1 Kilogram 1000 Grams 2 2 lb 1 Cu Meter 1 000 000 Cu Centimeters 35 31 Cu Feet 1 Metric Ton 1000 Kilograms 1 Megagram 1 1 Short Tons TEMPERATURE OCF 32 C LIQUID MEASURE 212 Fahrenheit is evuivalent to 100 Celsius 1 Milliliter 0 001 Liters 0 0338 Fluid Ounces 90 Fahrenheit is equivalent to 32 2 Celsius 1 Liter 1000 Milliliters 33 82 Fluid Ounces 32 Fahrenheit is equivalent to 0 Celsius 9 5C 32 F APPROXIMATE CONVERSION FACTORS TO CHANGE TO MULTIPLY BY Inches ead he raat Centimeters 2 540 i 4L puan hana tet Met T8 pp PAS 0 305 Yards sequ UA da weeks Meters yagua RET UN 0 914 Miles iv br ees Kilometers 1 609 Square Inches Square Centimeters 6 451 Square Feet Square Meters 0 093 Square Yards Square Meters 0 836 Square Miles Square Kilometers 2 590 E Square Hectometers 0 405 Cubic Cubic Meters 0 028 Cubic Yards Cubic Meters 0 765 Fluid Ounces Milliliters 29 573 MSs oro NEEDS EIS cea e aa 0 473 BIiS liters ra erg x ed 0 946 s pAlONS lll ege itu Ditet Sio eeina 3 785 O nce Sooden ee eee od
135. ual 3 12 PRESELECTOR BANDWIDTH 3 13 The YIG filter has a 3 dB bandwidth that is typically 20 to 45 MHz depending on the portion of the frequency spectrum in which it is being used illustrates a typical 3 dB YIG filter pass band display at 4 GHz using a 10 MHz Div analyzer sweep The Preselector is fixed tuned to 4 GHz The input signal is tuned through the passband Figure 3 2 Typical 3 dB Yig Filter Pass band Display at 4 GHz and with a 10 MHz DIV sweep 3 14 PANEL FEATURES 3 15 Front and rear panel features of the Stan dard Option 002 and Option_003 8445B Automatic Preselectors are described in Figure 3 3 Front and rear panel views of a Preselector connected to the HP 8555A 8552 141T Spectrum Analyzer are shown Figures 3 4 and 3 5 For a detailed description of the Spectrum Analyzer controls and indicators refer to the appropriate operating and service manuals for those instruments Interconnection wiring bet ween the Preselector and the Spectrum Analyzer is contained in Section VIII df this manual Model 8445B 11 6625 2781 14 6 Table 3 1 8555 Frequency Ranges and Recommended Mixing Modes Signal Frequency GHz Recommended Mixing Modes n Analyzer Frequency Range GHz 1 1 1 2 1 3 2 4 3 4 E 0 01 2 05 1 50 3 55 2 60 4 65 2 07 6 15 4 11 6 15 4 13 10 25 6 17 10 25 6 19 14 35 8 23 14 35 10 29 18 00
136. volts If not the Remote Control Buffer Amplifier described in Service Sheet 5 should be checked Adjust signal source to 4 GHz and vary the dc voltage The signal should peak on the CRT at 4 volts NOTE When switching the 8555A INPUT ATTENUATION from 10 dB to dB signal level displayed on CRT may not change by 10 dB This is dueto the high mismatch error between the 8445B OUTPUT port and the 8555A INPUT port Figure 3 5 1 8 to 18 GHz YIG Tuned Filter Operation 3 of 3 3 12 Model 8445B TM 11 6625 2781 14 6 LAMP DS1 KNURLED 2140 0244 PANEL NUT PUSHBUTTON 2 PLASTIC LENS POWER LAMP REPLACEMENT 1 Remove lens by pulling straight out 2 Replace lamp 3 To replace lens align guide with notch in receptacle Push straight in Figure 3 6 Power Lamp Replacement 3 13 3 14 Model 8445B TM 11 6625 2781 14 6 SECTION IV PERFORMANCE TESTS 4 1 INTRODUCTION 4 2 The procedures in this section test the instrument s ability to operate in accordance with the electrical specifications given in Table 1 1 All of the tests can be performed without access to the in side of the instrument A simpler operational test is included in Section Ill under Operator s Checks 4 3 Equipment required for the performance tests is listed in the Recommended Test Equipment table in Section I Any equipment that satisfies the criti cal specificaions given in the table may be substi tuted for the recom
137. wer Module printed circuit card is set for the nominal voltage value closest to the existing line rg phe l to 2 9 Nominal voltage used Vac With power line switch OFF connect the variable voltage transformer between power line and Preselector Adjust ac input to Preselector to the nominal line voltage value as indicated on ac Voltmeter Turn power line switch and voltmeter ON Allow 30 minutes for instruments to stabilize Remove Preselector top cover and connect the dc digital voltmeter test leads to the 19 5 V test point A2TP1 and to the common ground point A3TP2 Adjust A2R5 419 5 V ADJ for 19 500 Vdc on the dc digital voltmeter With the variable voltage transformer increase the ac line voltage to the Preselector 596 Record any dc voltage variation should not exceed 20 m Vdc Change noted Vde Decrease the ac input 1096 below the nominal line voltage level and record any change should not exceed 20 m Vdc Change noted Vdc Adjust to nominal ac line voltage input Measure and record the three other power supply levels at the test points listed 40 V x2 V at pin 4 on YIG TEK YIGs or at the pin on VARIAN YIGs b 28 V 1 4V at whitewire connection on the 2 terminal tie point adjacent to the YIG YIG heater supply not used with VARIAN 5 Vdc C 23V x12V at test point 2 7 Op Amp bias If dc supplies are out of tolerance refer to Service Sheets 4 and 6 for t
138. y 1 Power Range 20 to 10 dBm Power Supply Output Voltage Variable 0 20 Vdc Dual Dc Output Current 0 300 mA Meter Accuracy 3 Control Fine adjustment HP 6205B Power Supply Dc Volt ohm Voltmeter Ammeter Voltage Range 1 mV 300 V Accuracy 1 Input Resistance 10 megohms Ammeter Current Range 1 pA 1A Accuracy 2 Ohmmeter Resistance range 1 ohm 100 megohm Accuracy 5 reading at center scale HP 412A Volt Ohm Ammeter A Adjustments T Troubleshooting P Performance 11 6625 2781 14 6 Model 8445B Table 1 5 Test Equipment and Accessories 2 of 2 Minumum Specifications Suggested Model Frequency Range 0 01 18 GHz HP 8555A Spectrum Frequency Response 2 0 dB Analyzer with HP 8552 IF Section and HP 141T Display Section Spectrum Analyzer AC Voltmeter HP 427A Multifunction Voltmeter Voltage Accuracy 2 of full scale Voltage Range 300 Vac full scale Input Impedance 10 megohms General Radio W5MT3A or Superior Electric UC1M Variable Voltage Transformer Coaxial Cable Male BNC Connectors 44 inches long with alligator clips Frequency Range 2 18 GHz Overall Accuracy 0 2 Voltage Range 102 127 Vac HP 10501A Cable Assy w alligator clips HP 536A 537A P532A Frequency Meters Frequency Meter Sensitivity 5 dB div Blank
139. y applying a 5 dBm signal to the filter input the power level at the filter output is measured to establish a reference level The input power level is increased by 10 dB and the output level is checked for a corresponding increase the actual test a 10 dB fixed attenuator is switched from between the signal source and filter to the filter output Using this procedure any change in output level would be due to compression and not to errors in the measurement test setup DC POWER SUPPLY TO REMOTE BNC POWER METER bx B o SIGNAL GENERATOR POWER SENSOR 10 dB ATTENUATOR Figure 4 4 YIG Filter Signal Compression Test Setup EQUIPMENT Power Meter amp Power HP 435A 8481A Power SUDA ores doe ee Fei RF maana Mean Yan HP 6205B Signal Generator 5 MMC HP 8616A Coaxial Attenuator 100 HP 8491B Option 010 1 Connect test setup as indicated in Figure 4 4 and make the following control settings PRESELECTOR LINE ORF ION aeuo asus uate dca AC dea ad Arai erac es ON POWER SUPPLY Output Vollage ei 19 4 10 Model 8445B TM 11 6625 2781 14 6 PERFORMANCE TESTS 4 20 LIMITING LEVEL TEST Cont d 10 SIGNAL GENERATOR euch iE ha a tae gee sana mU waa ta erede gn Re On IAE

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