Tektronix P6046 User's Manual
Contents
1. Energize the equipment and depress the PUSH ON OFF button to light the Probe On lamp which is located in the PUSH ON OFF button assembly 2 6 NOTE The Probe On lamp will not light if the VOLTS CM control is at lower sensitivity higher VOLTS CM setting than 0 2 V The Probe is supplied with power whenever it is connected to an energized 1A5 regardless of the condi tion of the Probe On lamp Only the P6046 Probe inputs to the Type 1A5 are interrupted when the Probe On lamp is out ATTEN BAL PROBE STEP ATTEN BAL Adjustment a Connect special ground tips to the Probe and Input tips Wait 5 minutes or more for the equipment oper ating temperature to stablize b Set the CRT controls for optimum display c Check that the vertical deflection factor is set at 20 mV div Using the vertical position control set the oscil loscope trace to graticule vertical center d Change the vertical deflection factor at the Ampli fier For P6046 if used to 1 mV div and adjust the ATTEN BAL PROBE STEP ATTEN BAL control as necessary to re turn the trace to the center of the graticule Some small amount of drift of the trace vertical position can be ex pecled at mV sensitivity especially during warmup Repeat steps c and d until no further adjustment is necessary IMPORTANT The ATTEN BAL PROBE STEP ATTEN BAL ad justment should not be used as a vertical position control The Vertical POSITION2. DC coupled 2 oem ference between 4 and Input tips Gate Leakage Current _ 0 3 nA at 25 C lt 2nA at 50 C Warm up Time With Amplifier For P6046 Maximum Allowable Input 20 minutes for rated accuracies at 25 5 5 90 to 136 V 180 to 272 V 48 to 400 Change power connections for range and Hz voltage within range See Table 4 3 Amplifier For P6046 Operating Voltage Temperature operating 00 40 to 65 __ Operating 0 50 Altitude perature tests at 40 C Non operating 50 000 feet May be tested during Non operating Tem Operating i 15 000 feet dcs E 111 _ o Non operating 5 cycles MIL STD 202C Method 1068 omit _ fing freezing and vibration subeycles _____ Operating 15 minutes each axis at 0 015 inch Fre quency varied from 10 50 10 c s 1 min ute cycles with instrument secured to vibra tion platform Three minutes each axis at 15222 resonant point or at 50 c s 0 Shock Probe Body 400 g s sine 6 shocks along transverse axis at 1 ms and 2ms duration total of 18 shocks 3 additional shocks in longitudinal axis at ms 1 ms and 2ms total of 9 Amplifier 200 g s V sine 3ms or 7 ms duration 3 shocks each direction along t
3. pepunoi5 indu pesnun jo 50 uo annos 9 1 7514 15 8 H prec Gain 1 8 Characteristics P6046 Probe and Amplifier EPEER EH ac 2 100 MHz Input to positive tip negative tip grounded 1 9 FREQUENCY ti 53 e ubiDDdo5 7 P6046 Input capacitance and resistance versus frequency Fig 1 quii Ier a ed gt zw i ED i i ye 5 i 1 i 1 Pod NOTES P6046 Probe and Amplifier SECTION 2 OPERATING INSTRUCTIONS Change information if any affecting this section will be found at the rear of the manual CAUTION Operating the P 046 Differential Probe without a common reference ground between it and the unit under test may destroy components in the Probe input circuitry Connect a ground lead from the probe grounding lug to the equipment to be tested before touching the Probe to the equipment or its test jacks Introduction The P6046 Differential Probe is essentially a differential amplifier wit
4. CMRR 11000701 1 iride prre CZ am pooH aqoid oHuoojJIQ 99094 jo ouonber 2 0345 p i 00834 ZHW 001 ZHW z Hi 01 ZH 001 ee 2 001 CMRR pejdnoo 7 4 25 49 Anuanbesg 8 jojonueuy 274 9094 0941 511 000 01 SEE OR Unt Characteristics P6046 Probe and Amplifier Characteristics P6046 Probe and Amplifier UoISIAIp AU og oinipieduie NHWO 99033 99094 75 1 seejBop Er p puc E E BERN E LEE ______________ Ee ec oo oon 2 Hue E 42 E o o n Hb Bu gud ui 23 ELE aa eo 2 _ E muU cem pg zum or 95 09 oZ Percentage of 259 C CMRR 1 7 Characteristics P6046 Probe and Amplifier
5. Disconnect the adapter from the tip and remove the ground tip from the tip Attach the probe dual tip to BNC adapter to the Dual Attenuator Head Connect the BNC connector to the amplitude calibrator output jack using 42 inch coaxial cable Set the amplitude calibrator contro to 50 volts Measure the display amplitude and divide it into 50 volts The quotient is the CMRR of the Attenuator Probe Amplifier or 5 combination CAUTION Never exceed 250 V DC peak AC input to either of the Dual Attenuator Head Never exceed 250 V DC peak AC difference between Atten vator Input tips Additional Operating Hints Differential Amplifier Operation Connecting the two inputs fo separate signals will result in d display of the instantaneous phasor and amplitude differences between the two signals NOTE Do not exceed 5 V DC peak AC common mode input or 10 divisions of difference between sig nals for linear operation Never exceed 25 V DC peak AC difference between signals applied to the probe Operating Instructions P6046 Probe and Amplifier External Triggering Use of one of the signal sources to provide external triggering will introduce an apparent common mode dif ference due to the loading caused by the triggering circuit External triggering during differential measurements which require a high CMRR should only be used if identical load ing is provided to the second signal source or if a sign
6. differential amplifier as signals The capacitance of unshielded leads is relatively unpredict able and will vary with the lead location AC signals will be affected by this especially at high frequencies and a difference between the source signal and that delivered to the differential amplifier will occur Unless the introduced difference is equal in both leads the amplifier will again see a differential signal that is not actually present at the sources See Fig 2 2 The capacitance of shielded cables affects signals just as it does in unshielded leads However the capacitance of shielded cables is known and can be kept relatively equal by matching the two signal cables in every respect The cables should normally be short to keep their capacitance as low as possible Signal transporting cables can also affect the source sig nal by causing reflections These reflections can be eliminat ed by terminating the cables in their characteristic imped ance unless prohibitive source loading would result Attenuators Any device such as capacitors or resistors connected between the source and the amplifier unless per fectly matched will also cause additional differences be tween the signals at the amplifier Attenuators therefore normally lower a system s common mode rejection capabil This is illustrated in Fig 2 3 and its accompanying table Ground Connections in addition to providing a com mon reference for safety r
7. with a spring clip on one end intended to snap onto the Probe ground lug machine screw on the other end for attachment to an alli gator clip It should be connected between the Probe ground lug and the equipment being tested before the Probe is connected to the equipment Input inductance of 1 4 inch 22 wire 1 1 No 22 wire lead to input ds inch longer than lead to Input 259 EQUIPMENT UNDER TEST 10 000 1 Operating Instructions P6046 Probe and Amplifier 4 Input immo EQUIPMENT UNDER TEST CMRR resulting from induc five effect of Va inch dif ference between lengths of number 22 wire leads the two sources See Fig 2 2 5 3 resulting from 0 5 pF Ha difference shunt capaci 1 tance between leads coming from otherwise identical 1 7 255 Fig 2 2 Impedance effects upon apparent CMRR Amplifier For P6046 The Amplifier For P6046 is an optional P6046 Probe ac cessory consisting of an Amplifier unit and a Power Supply uni See Fig 2 4 It makes the Probe compatible with any oscilloscope and plug in combination which has 10 mV div deflection capability and appropriate bandwidth Operating it into a less sensitive d
8. with which the Head is shipped No further adjustment should be required unless the Head is used with a different Probe In that event the attenuator calibration procedure contained the Calibration section should be accomplished CAUTION 1 A common ground must always exist between the P6046 Probe and any equipment with which it is being used A ground lug is built into the Probe and ground leads are supplied as stand ard accessories for ground purposes 2 Maximum allowable single ended input is zx25V DC peak AC with respect to Probe ground 3 Maximum allowable difference between volt ages at the two tips is 25 V DC 4 peak AC The Type 1 5 controls associated with the P6046 Differ entia Probe operation are high lighted in Fig 2 5 None Operating Instructions P6046 Probe and Amplifier Fig 2 4 P6046 Differential Probe and Accessories Operating Instructions P6046 Probe and Amplifier of the other controls on the Type 1A5 directly affect the Type 5 operation while the Probe On lamp is on al though the comparison voltage Vc selected by the POLAR and AMPLITUDE controls is still available at the MON ITOR jack Preliminary Procedure For P6046 Differential Probe Amplifier For P6046 Operation The Power Supply Unit shipped with the Amplifier For P6046 is wired for 104 to 126V AC 50 to 400Hz operation Rewire the unit in accordance wi
9. INSTRUCTION MAN UAL P6046 Tektronix Inc S W Millikan Way 9 P Box 500 Beaverton Oregon 97005 Phone 644 0161 Cables Tektronix 070 0756 00 22229 OE is NS 2 x RE os 9522 5 5 2 de 2 23 55 20 2 io eS m idm um 2022 CSS MEN VU ee NS es 5 TE ORUM 2 VEU SUE d 555 gt uem 5224 is Ss is PIT P6046 Probe and Amplifier SECTION 1 CHARACTERISTICS Change information if any affecting this section will be found at the rear of the manual General Information The P6046 Differential Probe is an active dual input probe designed for use with the Tektronix Type 1A5 Differential Amplifier or the Amplifier For P6046 High common mode rejection ratios are provided at high frequencies by per forming the common mode rejection within the probe body Calibrated vertical deflection factors of from 1 mV through 200 mV division in 1 2 5 sequence can be selected switching at the Type 5 or at the Amplifier for P6046 These deflection factors can be increased to times the indicated amount throug
10. al associated source is available which will not affect the signal being observed Differential Comparotor Operation Any adjustable DC voltage source of 5V or less can be used for differential comparator operation COMPARISON VOLTAGE makes 0 to 5 volt DC output available which can be connected to one side of the Probe DC coupled while a signal is connected to the other side This enables common mode cancellation of an equivalent DC or instantaneous level of AC permit ting the observation of specific amplitude points on sig nals up to 5 V DC peak AC using a much more sensi tive VOLTS CM setting than would otherwise be possible Use a comparison voltage of the same amplitude and polar ity as that existing at the point being checked A 001 uF capacitor must be close coupled between the Probe tip and ground to bypass voltages induced in the Vc lead which would otherwise be accepted as signals io 21 Aem ek 1 3 H 1 remet Petra tin arat a A MIRI E a a e ee e A
11. control at the oscilloscope should be used for this purpose An occasional check of the ATTEN BAL adjust ment is recommended Single Ended Operation Gain Check NOTE The single ended linear operation limit of the Probe with or without the Amplifier For P6046 is or 10 divisions of DC peak AC deflec tion from 0 reference position The oscilloscope and vertical plug in limit must also be considered in determining the limit of the complete system CAUTION Breakdown voltage is 25 25 V DC peak and extends to 250 V when the Probe Dual udtor Head is installed a Connect a special ground tip P6046 accessory to the Input of the P6046 Probe Connect a probe tip to GR adapter to the Probe Input tip b The habit of ALWAYS connecting a ground lead before connecting the Probe tips should be developed Therefore connect ground lead and alligator clip 6046 Operating Instructions P6046 Probe and Amplifier Probe On Fig 2 5 Type 1 5 front panel high lighting controls directly associated with ihe P6046 Differential Probe operation Operating Instructions P6046 Probe and Amplifier Probe accessories from the P6046 Probe ground lug to a ground terminal at the oscilloscope Check that the oscilloscope s amplitude calibrator is off Set the Probe AC DC switch to DC Then connect the Probe fip to the oscilloscope calibrator outpu
12. de re jection ratio CMRR This ratio and associated terms are defined as follows Common Mode Refers to signals fhat are identical both amplitude and time lt is also used to identfy the respeclive paris of two signals that are identical am plitude and time Common Mode Rejection Ratio A ratio which expresses the efficiency of a device in preventing common mode sig nals from affecting its output A differential amplifier like all other things cannot be a perfect device Some output signal however small always occurs in response fo com mon mode signals applied to the two inputs In any spe cific instance an output resulting from application of com mon mode signals can be duplicated by grounding one input and applying a specific size signal to the second input The comparison of the common mode signal to the single ended signal is the Common Mode Rejection Ratio of the device See Fig 2 1 0 5 mV peak to peak 5V peak to peak signal Output caused by inability to completely reject common mode signals 0 5 mV 0 5 mV peak to peak peak to peak signal B Equivalent output caused by single ended signal 10 000 1 CMRR C CMRR ratio of amplitude of common mode signal to amplitude of single ended signal B which produces equivalent results Fig 2 1 Common mode rejection ratio NOTE Since the differential amplifier is part of an oscil loscope the output sig
13. div Accuracy Source impedance effect on Characteristics P6046 Probe and Amplifier Performance Requirement Ringing Rounding Over shoot and Tilt With Type 1A5 249 lt 6 peak to in first 70 ns 1 5 lt 2 peak to peak thereafter With Amplifier For P6046 lt 42 lt 2 peak to peak after the Percent of deviation specification increases irst 70 ns by 4 within the first 105 at 09 and 210 200mV DIV ____ 4 lt 5 peak fo in first 70 ns 50 1 mV DIV lt 59 lt 695 peak to peak in first 70 ns At 70 Voltage point 3 dB Basic 1 With 10X Dual Attenuator Head Deflection Factor uU i Basic 1X mV div to 200 mV div calibrated in 1 2 1 mV div through 2500 mV div uncali 5 steps brated with 1A5 With 10X Dual Attenuator 10mV div to 2 V div calibrated 1 2 5 10mV div through gt 5 V div uncalibrated Head steps with 1A5 With Type 1 5 1 mV CM to 20 0 Within 4 With Amplifier For P6046 Dual Attenuator Head Probe and Type 1A5 or Probe and Ampli fier For P6046 accuracy must also be con sidered gain as a function of frequency Basic 1 With 10X Dual Attenuator Head Common Mode Operating i Range DC to 10 MHz iypically within 1 5 5 DC peak from average sig nal level not exceeding i 5 V with re s
14. easons proper ground connec tions are essential for eliminating signal interference caused by ground loop currents Ground leads should be as short as possible in all instances ground lead should accom pany each signal lead to the proximity of the test jack The shield of the signal s coaxial cable is usually used for this purpose 2 2 Probe input tips very often are accidentally touched to equipment ground during insertion into test jacks suf ficient difference exists between the differential amplifier reference and reference for the equipment being tested valuable input components can be destroyed Proper ground ing will also eliminate this problem P6046 DIFFERENTIAL PROBE CONTROLS CONNECTORS AND ACCESSORIES The P6046 Probe and accessories are shown in Fig 2 4 The P6046 Probe has an Amphenol power and signal con nector dual signal input tips and AC DC Input Cov pling switch which controls the mode of coupling for both tips Accessories and their uses are as follows 1 Dual Attenuator Head Provides 10X attenuation of signals applied to its inputs Attaches directly to P6046 Probe tips Has same tip configuration as the Probe 2 Swivel Tips Sleeve type connectors which fit individu ally over probe tip input connectors Not equipped with coaxial ground connectors They adapt the probe tips to terminals whose spacings are between 3 and 1 inches 3 Spring Ground Clip Clips to coaxial ground at pr
15. eference The second result is that the time constant introduced by the coupling capacitor causes a tilt in the 1 kHz square wave presentation Return the Probe switch io DC and then turn the amplitude calibrator control off 2 8 Common Mode Rejection Check NOTE linear common mode operation with or without the Amplifier For 6046 can be obtained up to 5 V DC peak AC provided that the difference between the two signals does not exceed or 10 divisions of vertical deflection linear common mode operation is extended to 50 V DC peak AC when the Probe Dual vator Head is installed CAUTION The applied voltage must never exceed 25 V with respect to Probe ground The difference between the voltages applied to the two tips of the Probe must never exceed 25 V DC peak AC These values increase to 250 V when the Probe Dual Attenuator Head is installed Disconnect the Probe and adapter the calibrator Remove the adapter from the one tip and the ground tip from the other Connect the calibrator signal to both tips using a probe dual 4 female adapter and a 42 inch 500 coaxial cable equipped with BNC male con nectors Set the amplitude calibrator control to 5 V and the vertical deflection factor to 1 mV Set the oscilloscope trig gering controls to stabilize the presentation if possible The CMRR may be so high that insufficient signal exists to trigger the oscilloscope Divide the peak
16. evice higher mV div will provide unreliable results because of overdriving the Probe and Amplifier Operating it into a more sensitive device can produce some usable results if proper consideration is given to the signal to noise ratio The Power Supply unit attached to the Amplifier P6046 must be wired to conform with the source voltage Three ranges are available in the vicinity of 115 V AC and three are available in the vicinity of 230 V AC Connection instructions are contained in the Maintenance section The Amplifier For P6046 comes equipped with the fol lowing accessories 18 inch 500 coaxial cable with which to couple its output fo an oscilloscope input connector 2 3 Operating Instructions P6046 Probe and Amplifier X10 Probe A AAT 9 i 1 resistors X10 Probe B Differential amplifier Worst case CMRR difference limitation between introduced Probe A and by probes Probe B 0 5 resistors 2 1 resistors 5583 10 5 resistors Fig 2 3 Simplified circuit showing the limitation CMRR that a difference between attenuator probes can introduce Differences between probe capacitances add to the effect signals A 500 BNC termination with which to terminate the Amplifier output A hanger bracket which can be mounted at a convenient location on the side cover
17. h unity gain Proper operation of it is de pendent upon a basic knowledge of differential principles summary of these principles therefore precedes the op erating instructions GENERAL DIFFERENTIAL AMPLIFIER INFORMATION oscilloscope with a differential amplifier is device that amplifies and displays a voltage difference which exists at every instant between signals applied to its two input connectors The following conclusions can be drawn from this definition 1 the two signals are in phase and of equal ampli tude hereafter called common mode the output will be zero 2 If the two signals are in phase but of different ampli tudes the output will equal the amplitude difference 3 If the two signals are out of phase and of equal am plitude the output will be the phasor difference between the two signals sinusoidal signals 4 If the two signals are out of phase and of different amplitudes the output signal will be a complex quantity derived from both amplitude and phase differences Common Mode Rejection The definition of the term differential amplifier implies rejection of equal amplitude coincident signals This implication is correct However the degree of rejection de pends primarily on the symmetry of the amplifier inputs The amount of difference signal contributed by a particular amplifier at a specific frequency is documented with a math ematical relationship that is called the common mo
18. h use of a calibrated Dual Atten vator Head which is a standard accessory to the P6046 Probe The Probe and Type 5 combination has 45 MHz bandwidth when used with an appropriate oscilloscope The Probe and Amplifier For P6046 combination has a 100 MHz bandwidth This provides a 70 MHz overall system bandwidth when the Probe and Amplifier are operated into the single ended input of any 100 MHz oscilloscope having a vertical deflection factor of 10 mV division The Probe has 5 common mode operating range and a 25 V maximum input which can be extended by a factor of ten through use of the Dual Attenuator Head Characteristics summary of the P6046 Differential Probe electrical char acteristics and pertinent mechanical and environmental characteristics are contained in Table 1 1 Specifications per tain to operation with both the Type 1A5 and the Amplifier For P6046 except where noted otherwise Fig 1 2 1 3 and 1 4 contain graphs of common mode rejection ratios CMRR under different equipment setups at 25 MINIMUM refers to the values required to meet spec ifications TYPICAL indicates the approximate values which most probes will obtain Fig 1 5 shows how CMRR varies as temperature deviates from 25 C For example if the Probe is to be operated at 20 C to test a 50 MHz circuit the specified CMRR should be multiplied by 0 95 to determine the minimum CMRR value which may be expected Fig 1 6 displays t
19. he 3 major axes for a total of 18 shocks 22112 EDI Transportation DEED Package Vibration 1 hour at m Package Drop 30 inches on 1 corner all edges radiating from that corner and all flat surfaces for a total of 10 drops e 2411 2 IRR Dimensions inches 00 ee NEM TORNA Probe Body 2 um _ ese tee Amplifier 777 936 Power Supply 1212 5100 235 0295 26 Power ver Cable uu D 1 3 3 266 19 OG Asuonbos YYW 99094 76 751 lt HW ZHW 001 065 ZHW OL zHW ZH 001 ZW 01 ZH ZH 001 7H 01 1 001 pejdno 1 005 0001 56 19 6 9 Au d Kouenbei SA YYWD 97094 9 17000701 2 lt E 1 000 001 5 3 2 D 2 1 28 5 5 5 5 sr 1 8 pem peutojeuy Au OZ puo 01 o segddo 2 84 10 UOISIAIP 000 nodu 06 10 529 YYWD 9 094 6 1 Ei 1 5 ZHW 001 ZMW OL ZHW 1 ZW OGL ZH 01 1 zH 901 ed jo 9 09 io 4 SA 98094 pad s i 12000 Characteristics P6046 Probe and Amplifier
20. he effect that source Impedance has on the gain of the Probe as a function of frequency If can be ap plied to differential operation as follows Relate the upper graph fo the display amplitude input signal when the signal source impedances are matched to 5 1 source impedance ratio Relate the lower graph to the display amplitude input amplitude when the signal source imped ances are greatly mis matched Accessories A number of accessories which extend operating capabil ities are supplied with the P6046 Probe and the Amplifier For P6046 as Standard Accessories These are listed on the last page of the Mechanical Parts List An optional accessory which must be used during Probe calibration is listed in the Calibration section Additional miscellaneous accessories are listed in the Tektronix catalog All accessories be purchased through the Tektronix Field Office TABLE 1 1 CHARACTERISTICS Characteristic Step Response With 1A5 5 to 200 mV CM Bandwidth gt 45 MHz 2mV CM and 20mV 243 CM Retained Range Performance Requirement at 25 Supplemental Information 1 mV CM and 10 mV CM Retained Range With Amplifier For P6046 1 mV DIV through 200 mV DIV e decreases to 90 MHz at 50 1 1 AC Low Frequency Response mV
21. nal used to calculate the CMRR is measured from the CRT display and VOLTS CM switch setting 2 1 Operating 1 5 5 6046 Probe and Amplifier Factors Which Affect CMRR Frequency Since the common mode rejection ratio is affected by the gain and phase shift introduced by the two sides of the amplifier the frequency of the input common mode signal has a direct bearing on the CMRR General ly as the frequency of the input signal increases the CMRR decredses Exception with AC coupled inputs the CMRR will become higher as frequency is increased from DC to over 1 kHz Source Impedance obtain optimum CMRR points being measured must have identical source impedance The source impedance and the amplifier input impedance form an RC divider which determines the portion of the signal that appears across the amplifier input Unequal source impedances show up as an apparent decrease in CMRR Signal Transporting Leads The input connectors of a differential amplifier are usually remote from the actual signal source Even with a portable amplifier such as the P6046 Probe some transporting of the signal is required from the source to connectors which are compatible with the Probe inputs Several undesirable effects can be introduced by trans porting leads they are unshielded stray pickup will occur Differences between the stray pickup in the two leads will be accepted by the
22. obe tip Equipped with wire soldering lug 4 Special Ground Tip Sleeve type adapter Internally short tip to coaxial ground connection Adapts Probe for single ended operation common ground connection be tween the Probe and the equipment under test is still re quired 5 Test Jacks Coaxial female connectors normally in stalled permanently into or near the equipment being tested Spacing should conform to the 1 inch tip spacing If the swivel tips are used with the probe additional spacings are possible should be noted that no coaxial ground con tact accompanies the swivel tip The test jacks can be in stalled by drilling holes through the selected mounting plate inserting the threaded end through from the front of the plate and fastening the test jack in place with a nut and star washer A soldering lug can be fastened between the nut and the back of the plate to facilitate the making of ground connections 6 Alligator Clip Threaded for use with ground leads 7 Hook Tips Sleeve type connectors which fit individu ally over probe tip input connectors Facilitates hanging the Probe into circuitry 8 Insulating Tube Sleeve type adapter for insulating the tip s coaxial ground Permits use of tip in close quarters with minimum danger of causing a short circuit 9 12 inch Ground Lead Same 5 inch except that it should be used only when the 5 inch will not reach 10 5 inch Ground Lead Equipped
23. of the oscilloscope with which it is used HANDLING THE PROBE The P6046 Differential Probe is made as rugged as sible without sacrificing performance or portability How ever ifs sensitive circuitry small size and mobility make necessary the use of some caution in its handling Use normal care to avoid severe mechanical shocks to the de vice and do not subject the circuitry to voltages in excess of its breakdown values t is suggested that points to be checked be tested with another device to insure that volt ages do not exceed the P6046 Probe capabilities OPERATING PROCEDURE The P6046 Probe is designed to operate either with a Type Differential Amplifier Plug in Unit or with an Amplifier For P6046 whose output is connected to an os having 10 mV div vertical sensitivity and appropriate bandwidth This procedure covers both situa tions it includes setting up the equipment performing operator adjustments checking gain through single ended operation checking common mode rejection observing AC coupled operation and attenuator operation Differential operation and external triggering operation information is also included Pertinent precautions are contained along with techniques to improve operating results 2 4 Equipment Required The following equipment is recommended for use in this operating procedure Oscilloscope Tektronix Type 544 546 547 or 556 580 Oscill
24. oscope may be used if it is equipped with a Type Plug In Adapter If the Amplifier For P6046 is to be used with the P6046 Probe any oscilloscope and plug in combination having a vertical deflection factor of 10 mV div and an appropriate bandwidth can be substituted Differential Amplifier Plug In Unit Not re quired if the Amplifier For P6046 is to be used with the P6046 Probe Amplifier For P6046 and Standard Accessories Tektronix Part 015 0106 00 Not required if a Type 1A5 Differential Amplifier Plug In Unit is used P6046 Differential Probe Dual Attenuator Head and Standard Accessories Probe Tip to GR Adapter Tektronix Part No 017 0076 00 GR to BNC Male Adapter Tektronix Part No 017 0064 00 50Q Termination Tektronix Part No 011 0049 00 Not required if the Type 1A5 is to be used Probe Dual Tip to BNC Female Adapter Tektronix Part No 067 0562 00 42 inch Coaxial Cable Tektronix Part 012 0057 01 GR to BNC Male Adapter Tektronix Part No 017 0064 00 Operator Adjustments No adjustments at the Probe are associated with routine operation attenuator balance adjustment is available at both the Amplifier For P6046 ATTEN BAL and the Type 1A5 PROBE STEP ATTEN BAL to eliminate trace shifts which might otherwise accompany switching from one deflection factor to another The exposed adjustments in the Dual Attenuator Head have been factory calibrated to the Probe
25. pect to ground Decreasing 5V DC peak at 10 MHz to 62 at 50 MHz 10 div Linear Differential Input Range Common Mode Rejection Ratio 25 C Typically 100 1 at 100 MHz when used with Amplifier For P6046 See Fig 1 200 lt 2121 See Fig 1 5 for temperature effects 00 50 mV div through 200 See Fig 1 3 Also pertains to 10 and 20 mV Retained _______ Range positions of 1 5 In combination with 10 See Fig 1 4 _ Dual Attenuator Head MEE RENDERE 1 251 See Fig 1 7 10 pF or less see Fig 1 7 _ NEUEN 3 pF less DC Thermal Drift Pobe __ _ Equivalent to 55250 nV C at Probe head Amplifer _ lt 450 combined drift of Probe and Amplifier 1 2 Characteristics P6046 Probe and Amplifier Characters _ Performance Requirement Supplemental Information Displayed Noise 1 A With Type 5 B With Amplifier For P6046 280 nV tangentially measured RMS value is approximately of the tan gentially measured value Peak to peak value is approximately 5 1 times RMS Overdrive Recovery Time With Type 1A5 5V Input 0 15 us or less to within 10 mV of DC shifted level 0 1 ps or less to within 10 mV of DC shifted level 25 V total DC Peak AC 25 total dif
26. t jack via the probe tip to GR adapter and the GR to BNC male adapter CAUTION The output from the amplitude calibrator must never exceed 25V while is applied to the P6046 Probe d Set the vertical deflection factor and the amplitude calibrator output to the values given in Table 2 1 Set the triggering and position controls to obtain a centered stable display Check the display for the specified amplitude at each setting NOTE Although the gain can be adjusted to obtain exact results adjustment is not recommended if the gain has been previously set with a standard amplitude calibrator Most standard amplitude calibrators have a higher accuracy than calibra tors which are built into oscilloscopes TABLE 2 1 P6046 GAIN CHECK Vertical AMPLITUDE Deflection CALIBRATOR Factor Amplitude Tolerance _ 200 5 TmV 5cm 10 25mV 5mV cm 59V ud AV mete See 50 mV Retained i erformance _ Range 20 Check AV Retained Sem e Range 2 2 50 4 __ 100 200 2 only VOLTS CM knob placed 50 mV then pulled out and rotated clockwise e Switch the P6046 AC DC control to AC Two effects are obvious The 0 DC reference supplied with the cali brator signal is blocked by the coupling capacitor and the waveform shifts down 2V divisions to operate above and be low the Probe DC r
27. th table 4 3 located in the maintenance section if the unit is to be used with voltages outside this range Then connect the Power Supply Unit to the voltage source b Connect the P 046 Probe Amphenol connector to the Amplifier For P6046 Connect the output of the Amplifier For P6046 to the vertical input of the oscilloscope if the oscilloscope has 500 input impedance the connection may be made directly through the 50 coaxial cable If the oscilloscope has a high input impedance the 500 cable must be connected to a 500 termination Amplifier For P6046 standard accessory at the oscilloscope input con C Preset equipment controls as follows Oscilloscope Sweep Rate 0 2 ms div Triggering Automatic Internal Amplitude Calibrator Off Vertical Deflection Factor 10 mV div Calibrated Amplifier For P6046 mVOLTS DIV 20 d Do not change the calibrated vertical deflection fac tor at the oscilloscope for the remainder of this procedure All vertical deflection factor changes must be made at the Amplifier For P6046 Preliminary Procedure for P6046 Probe Type 5 Operation a Insert the Type 1A5 into an appropriate oscilloscope and preset the controls as follows Oscilloscope Sweep Rate 0 2 ms div Triggering Automatic Internal Amplitude Calibrator Off Type 1A5 POSITION Midrange VOLTS CM 20 VARIABLE CAL b Connect the P6046 Differential Probe Amphenol plug to the DIFFERENTIAL PROBE jack on the Type 1A5
28. to peak value of the presentation into 5V to determine the CMRR which is in effec LACK OF IDENTICAL SIGNAL CONNECTIONS TO THE TWO TIPS WILL DECREASE THE APPARENT CMRR If the two tips were connected to two separate signals the common mode portions would be almost totally rejected with the difference between the two being processed for display b Switch the P6046 AC DC control to AC and again cal culate the CMRR slight increase in display amplitude and a change in the shape of the presentation will possi bly be noted Both are caused by the lack of total identity between the matched input coupling capacitors c Turn the oscilloscope amplitude calibrator off and disconnect the Probe and adapter from the calibrator out put jack Remove the adapter from the Probe Attenuator Operation a Attach the Dual Attenuator Head to the Probe At tach a special ground tip to the Input Connect the Probe Input tip to the oscilloscope amplitude calibrator jack using the probe tip to GR adapter and a male adapter Set the vertical deflection factor to 20 mV and the amplitude calibrator to 1 volt Set the triggering and position controls as necessary to obtain a centered square wave 5 cm square wave with sharp corners should be observed indicating X10 attenuation of the amplitude calibrator signal and proper compensation adjustment Re move the adapter from the amplitude calibrator output jack b
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