HP 8970B Option 020 Service Manual Supplement
Contents
1. 6 8p NE02135 5 11k 228 NO LOAD Va Va pen Va Va Va 216 pee ME bend 602 MHz OUT Pe Be 688 MHz OUT 1 8p C17 R13 Va Qu 214 1 Li 2 2p I RIB gt Ik y M 46 4 l Va Va m 2 RP 1192 2 3 VA BFR96 L3 RS CW Va 220n 180k R Cil Va Dn 100K wl 4 7p D 66p cia VA NO LOAD 0 010 Va 15VF1 FLA Va 22258 Va Fa TD 1 R7 TUNE Bis 2 Va KARR VTO TUNE n NO LDAD T Tuo LOAD Dia a ih 4 7p 4 7p NO LOAD NO LOAD 177 A A CIRCUIT GROUND 18 ESTABLISHED THROUGH THE HOUSING i FL2 NO LOAD I E POWER SUPPLIES GND cn Va R19 21 5 FL3 RES nek 1 15 15VF ES 1SVF Era APR eyed N cel cz I BPG 6 8u 77 FLY M zr 1 R21 z Es z 18k U 15VF 15vF n E C23 C24 2 01 9 210 HP 8970B Option 020 Service Manual Supplement 6 3 Board Details for Assembly 08970 60097 ing Component Layout Draw Input Section Figure 6 3 h JLON 445 S3HONI 6527 ANY ZM WOYS NMOG S3HONI 527 ATALVWIXO yog 40 4415 1IN9419 NO lt dW 138V 1 AYLNNOI ATENISSV IVIINVHIIN 904 6009 0 6980 0 OL y 9 3L0N 3332 JaIs LINSUII 50 0 553202. P O 6 INPUT ASSEMBLY 08970 60097 FLL l NOTE PEN TO ADD PHASE LOCK OUTPUT REPLACE R34 WITH A 147 OHM RESISTOR AND LOAD X R35 R36 AND J I a mu EE FL2 l NO LOAD R35 38 3 Je ona PHASE LOCK NO LOAD Y R34 R36 51 1 147 NO LOAD R39 FL3 A Va 100 SOPA I R33 100 X ui 17 dB Y J4 Va LO MONITOR FL4 NO LOAD I J3 R3 R31 HN EOSIN gt gt 100 237 J5 X L __ MIXER LO FLS 35VF1 cre 1SVF ECT cre 15VF1 cas 1SVF1 ren BAS16 BAS16 BASI5 BAS16 BAS16 Y El E2 E3 Eu ES E6 E7 E9 Ela I I I R1 R2 R3 Ru RS R R7 51 1 51 1 51 1 51 1 51 1 51 1 51 1 51 1 51 1 51 1 I Lou pass filter is printed KIA K2A K3A KSA on the PC board 9 1 1 1 1 9 9 3SDS1026A2 38DS1 26A2 3505102682 35261026 2 35061026 2 EM EON EE A Siete ee E A Senn I V dl l 1580 39 7 3 boa 37 5 7 ism Reg 1588 Hs 3SDS1 26A2 3SDS1 26A2 3SDS1 26A2 3SDS1 26A2 3SDS1026A2 3SDS1 26A2 3SDS1 26A2 3SDS1 26A2 3SDS1 26A2 ml 12 1 ne J2 1 2 2 2 2 2 il RE DUT E fre ec D Tres ko f y Tros ws y free LM m s R12 R17 R20 422 422 75 75 75 Va I R11 lt R14 R15 R16 R18 R19 R21 eae 100 5 100 51 1 51 1 100 5 100 100 100 AES DAE usas Va VA Va 15VF2 Va Va Va l FL
3. O EE 923 a oo San O 4 LM CD HLI9N31 ANYI 40 OT B NVHL 5537 38 LON LSNW V JINVLSIA E ONVHH3AO ANZ E M ANYI YO LNINOdWOS JO 00 Q1 NYHL 5531 ONVHYSAG 3415 114714222 Ian gu SNVHYSAO 3018 ON NOILIGNOO 135471 gt SdW Ap 40415 i V 9cdMW 2 4 614 14 G2 di SNHdLIVd NV NINOIWNOD I 9I4 f HP 8970B Option 020 Service Manual Supplement 6 6 Figure 6 6 nput Section Schematic for Assembly 08970 60125 l dB PAD 3 H gt l dB PAD 2 H 20dB OUTPUT H 2 dB INPUT H l dB PAD 1 H RF INPUT GND NOTE 15V my P O 6 INPUT ASSEMBLY 08970 60125 Board Details FLA NOTE fenes TO ADD PHASE LOCK OUTPUT REPLACE R34 WITH 147 OHM RESISTOR AND LOA
4. 5 5 4 5 GHz Low Pass Filter 9135 0169 5 5 Second Convertor 5086 7909 000 0 ELLLER ERE 5 6 600 MHz SAW Oscillator 08970 60093 5 6 Board Details a 6 1 Contents 2 HP 8970B Option 020 Service Manual Supplement Block Diagram and Parts List Block Diagram and Parts List Block Diagram Block Diagram Figure 1 1 HP 8970B Option 020 Front End Schematic 2 05 GHz Low Pass Filter 4 Wl 50 Q w2 DM HARE 14 U a x gt 9 gt 13 gt 1654 PAD 1 mmm 924 lt ta PAD2 w 925 n PAD wm 926 INPUT ASSEMBLY lt 1 W6 ISOLATOR I P 4 5 GHz LPF TO A4 ASSEMBLY 600 MHz SAW Oscillator 1 2 HP 8970B Option 020 Service Manual Supplement Block Diagram and Parts List Front End Front End Fiaure 1 2 HP 8970B Front End Schematic gt E vx 20 dB 10 dB 10 dB Limiter 10 dB INPUT ASSEMBLY 10 2047 MHz Limiter on 08970 60125 Input Assembly only Suppresses externally generated transients YTO Output 3 910 5 947 GHz 2 7 GHZ Isolator 4 5 GHz LPF 3 9 GHz 300MHz To A4 Assy 2nd Convertor HP 8970B Option 020 Service Manual Supplement 1 3
5. 44 404 ESCLBE L s 1001 40 4944 1431 eta 7964 UNV SEY 914413 9C 4 01 LO 4398V1 NO 1 4398V1 39V ld SYSHLO NVHL 398v GNNOYS 5 IN 3415 WOLLO HOHJ S4 tM M3 24 M M ZM IVO 3sf 044 qvo 3434 Od 16002 01680 YSqWNON Cyvod 412345 3SIMYSHLO SSFINN S310 113 E T dH 214 E 14 VO ON 913 814 143 hid dH Tan VO ON 6 14 amp 14 351 5 6 HP 8970 Option 020 Service Manual Supplement 6 4 Figure 6 4 Input Section Schematic for Assembly 08970 60097 l dB PAD 3 H5 l dB PAD 2 H 2 dB OUTPUT H 20dB INPUT H l dB PAD 1 H RF INPUT GND NOTE 15V 15V Board Details
6. 1 Microwave Isolator 0960 0638 1 Right Angle SMA F to SMA M Adapter W6 1250 1249 1 4 5 GHz Low Pass Filter 9135 0169 1 SMA M to SMA M Adapter W7 1250 2189 1 Second Convertor 5086 7909 1 600 MHz SAW Oscillator 08970 60093 1 Flexi Cable W8 83711 60035 1 Flexi Cable W9 83711 60035 1 Main Wiring Harness 08970 60046 1 Firmware EPROM s 08970 80071 72 2 20 MHz IF Assembly 08970 60050 1 Driver Board Assembly 08970 60089 1 1 SMA M 50 Termination 0960 0053 1 Replaces 08970 60097 from prefix break 3811 2 This is the same part number as the main instrument but different wires are used The wires that are not used aretied back 3 These replace 08970 80051 52 4 Replaces 08970 60003 5 Replaces 08970 60034 HP 8970B Option 020 Service Manual Supplement 1 5 Block Diagram and Parts List Material List 1 6 HP 8970B Option 020 Service Manual Supplement Theory of Operation Theory of Operation General General The input range of the instrument is 10 MHz to 2047 MHz The input signal is first low pass filtered using the 2050 MHz filter to avoid images The YIG tuned oscillator tunes over the range 3910 MHz to 5947 MHz to mix the incoming signal to a first IF of 3900 MHz The isolator ensures that any rejected signals are absorbed in the isolator and do not interfere with the front end detector circuitry The second convertor mixes 3900 MHz down to 300 MHz There is a cavity tuned bandpass filter which
7. 15VF T AMPL 108 u2 VA 2 SPP90 3068 fes en 7 cw FLO 1 Y Case INPUT men CIRCUIT GROUND IS ESTABLISHED THROUGH THE HOUSING E E T DETECTOR V 470p 2 77 2 A u 2 Va Y gt 1SVF2 15VF aom R25 R26 9 1u 42 2K 120 Va per LE R23 E 18 0 lu FL Li Va i 4 7 en ARE 15VF Bee T fa 51 1 o RTI B 1u 200 Y l E Va Va FLE 12 I 4 7u am m 15VF A6 HP 8970B Option 020 Service Manual Supplement 6 7 Mixer SAW Oscillator Board Details Figure 6 7 HP 8970B Option 20 Hardware Input 8 5 8970B Option 020 Service Manual Supplement 6 8 Reorder No 08970 90115 O Copyright 1998 Hewlett Packard Ltd Printed in UK May 1998 Manufacturing Part No 08970 90115 08970 90115
8. Block Diagram and Parts List Front End Figure 1 3 Schematic Representation of Input Assembly 3GHz PAD LPF Limiter 10 dB 20 dB 10 dB 10 dB en PAD AMP PAD PAD Detector Limiter on 08970 60125 Input Assembly only This is a schematic representation of the RF input assembly The amplifier section and each and each of the attenuator sections are switchable by the control lines On units using the Input Assembly 08970 60125 the Limiter suppresses externally generated transients In Figure 1 1 the numbers in brackets inside the input assembly refer to the wire colors The numbers at the side of the second convertor refer to the wire colors attached to the connector which connects up to the second convertor 1 4 HP 8970B Option 020 Service Manual Supplement Block Diagram and Parts List Material List Material List Table 1 1 HP 8970B Option 020 Material List main differences for Option 020 Description Part Number Quantity 2 05 GHz Low Pass Filter 0955 0634 1 Semi rigid cable W1 08970 20082 1 Input Assembly 08970 60097 1 Input Assembly 08970 60125 1 2 to 8 GHz YIG Tuned Oscillator 0955 0630 1 YIG Tuned Oscillator Interface Board 08970 60045 1 YIG Tuned Oscillator Shield 08590 00047 1 Semi rigid cable W2 08970 20081 1 Semi rigid cable W3 08970 20083 1 Semi rigid cable W4 08970 20085 1 Microwave Mixer 0955 0635 1 Semi rigid cable W5 08970 20084
9. GHz The best way to measure this part is to use a network analyzer An alternate way is to use a spectrum analyzer e g 8593E with a tracking generator or a separate sweeper Verify over the frequency ranges above that the insertion losses are correct 5 2 HP 8970B Option 020 Service Manual Supplement Fault Finding Tips Input Assembly 08970 60097 or 08970 60125 Input Assembly 08970 60097 or 08970 60125 Figure 5 1 Input Assembly je 5 Limiter 10dB A PAD Ede EM Se 10 dB 10 dB PAD PAD LPF Detector Limiter on 08970 60125 Input Assembly only The easiest way to determine any problems with this section is to use a signal generator or sweeper which can cover the frequency range 10 MHz to 2047 MHz and can output 20 dB m The main source of problem with this assembly is that the pads are not switching or the amplifier has been blown up The common error when this is the case is error 27 The philosophy of repair for this assembly is board level repair sothese diagnostics are intended to prove that the assembly is defective or not and replace it From the functionality viewpoint it is possible to check that pads and amplifier are working individually by using Special 63 X To verify the pads and amplifiers of with the 8970B completely boxed up use the procedure RF Attenuator Checks in the Service Sheet BD1 section of the standard 8970B manual The voltages will be approximately correct
10. 6 NO LOAD u f BE R32 R37 10k AAA i 5 6 8 15 p22 TIME 15VF t AMPL 100 TS SPP9D 3868 ems 7 cw FLO Y Va d 3 vM Ense R38 a INPUT E C2 mn CIRCUIT GROUND IS ESTABLISHED THROUGH THE HOUSING 92 5 pm T DETECTOR Va 246 Va Y 4 gt 1SVF2 15VF an R25 R26 ee 42 2k 100k Va uw I I R23 I gt 15VF1 10 0 1u FLT Li Va i men rom 1SVF R24 I hol 51 1 RTI 1 3 8 1u Y Va Va FLO I L2 4 7u wen A 15VF 3 1 Va ES 2 2 ae ae iam __ __ Be E 2 A6 HP 8970B Option 020 Service Manual Supplement 6 5 for Assembly 08970 60125 ing Component Layout Draw ion Input Sect Board Details Figure 6 5 SINVNIWYINOO 40 3333 Nv319 SI 39V8L 0 33NSN3 S CI 914 3135 NXJLLYd ANYI 434909 OL 1934534 HLIM 319V901 ATIV8LN39 NV ayvoa OL HSNI4 3QY01 34 OL 899 NV 37 SLYVd h ges ANY SEH QVO 1 LON 04 e dvd NO dvi 4494Y 39V ld SHYSHLO NYHL 3394Hv dvi 0 010849 JNO 5 IN 2 S 62102 0 680 YJJWNAN MYY JSN I ON 031412395 3SIMH3HIO SSIANN SJ
11. B 6300 to 8400 MHz gt 60 dB HP 8970B Option 020 Service Manual Supplement 5 5 Fault Finding Tips Second Convertor 5086 7909 Second Convertor 5086 7909 This part contains a X6 multiplier a bandpass filter a mixer and a lowpass filter The 3900 MHz is mixed with the 600 MHz multiplied by 6 to give a 300 MHz IF Internally the 3900 MHz is bandpass filtered and the 300 MHz is lowpass filter to prevent the generation of images Under no circumstances should the bandpass filter be adjusted as this is a very complicated process and will impair the performance of the microcircuit 1 J Listhe RF input at 3900 MHz 2 J2isthelF output at 300 MHz 3 J 3is not used 4 J 4isthe LO input at 600 MHz Power should be between 1 and 4 dBm 5 J 5isthe LO monitor at 3600 MHz This is about 30 dBm with the above input range for the 600 M Hz The conversion loss between the 3900 MHz input at J 1 and the 300 MHz output at J 2 is about 6 dB With a 25 dBm input signal at J 1 the output at J 2 would be approximately 31 dBm It is possible to verify these levels by using a signal generator and a spectrum analyzer The supply connections are shown in Figure 1 1 600 MHz SAW Oscillator 08970 60093 This board delivers the 600 MHz to the second convertor Figure 3 2 shows the adjustment procedure The frequency should be 600 MHz 50 KHz The power should be gt 3 dBm 5 6 HP 8970B Option 020 Service Manual Suppl
12. D X I R35 R36 AND J6 I ws E FL2 l NO LOAD R35 38 3 l COR PHASE LOCK NO LOAD X R34 R36 51 1 147 NO LOAD R39 FL3 A Vi 100 AR I R33 100 Y 1 17 dB Ju VA LO MONITOR FLu NO LOAD J3 R30 R31 nee COIN gt gt 108 237 JS Y RER MIXER LO FLS 1SVF1 cre 1SVF 15V cRy 1SVF1 crs 1SVF1 en BAS16 BAS16 516 516 BAS16 Y El E2 Ez Eu ES E6 E7 EB E9 Eig R1 R2 R3 RS R R7 Re R9 Rig 51 1 51 1 51 1 51 1 51 1 51 1 51 1 51 1 51 1 51 1 I Low pass filter is printed KIA K2A K3A KUA on the PC board 9 1 1 9 9 1 1 9 1 3505102642 3505102642 12 2 0 70 12 2 0470 12 2 0 70 S L 32 2 EE ME AE RUE RM I V Ci ce J1 LE 7 7 R28 15088 3505102652 73 3SDS1 26A2 3SDS1 26A2 EZ 3SDS1B26A2 KE 2 5 12 21 n E 5 12 1 42 1 2 8 8 2 1 1 1 a TERMES EE 1 lI 11 RF DUT 412YZ B47B Ay fr 412Y2 B478 412YZ 47 L L T KIE fip pee Hees ERR t5 18X 5 10 5 185 t5 18 6 R27 R29 R12 A A A R17 A A R20 4 422 422 75 75 y zyz au7zo 75 412 2 0 70 I I 01 963 101 983 n R11 R13 R14 R15 R16 lt R18 R19 R21 cre Va Va 100 100 51 1 51 1 198 100 100 100 cV pne usa2n Va Va Va 15VF2 Va Va Va A A l FL6 LOAD ul n EE R32 R37 18k XGA i 3 6 8 2 pee
13. HP 8970B Option 020 Service Manual Supplement Service Manual Supplement HP 8970B Option 020 U Y HEWLETT PACKARD HP Part no 08970 90115 Edition 1 May 1998 UNIX is a registered trademark of AT amp T in the USA and other countries OSF Motif is a trademark of the Open Software Foundation Inc in the USA and other countries Copyright Hewlett Packard Company M ay 1998 All rights reserved Reproduction adaptation or translation without prior written permission is prohibited except as allowed under the copyright laws Printed in theUK ii HP 8970B Option 020 Service Manual Supplement Printing History Printing History Manual Date Edition Notes May 1998 08970 90115 HP 8970B Option 020 Service Manual Supplement iii List of Related Publications List of Related Publications HP Part Number Title 08970 90054 HP 8970B Noise Figure Meter Service Manual About this Manual This document is a supplement to the HP 8970B Noise Figure Meter Service M anual 08970 90054 and provides information useful for operating the HP 8970B Option 020 It also gives some troubleshooting tips iv HP 8970B Option 020 Service Manual Supplement Table of Contents Page Printing een ER edu ree bi pe Hine Raus eh de dE iii List of Related Publications eere t t eer a tee frg cu iv About this Manuala Sa his ed Gd ER da Ecl iv Block Diagram and P
14. It is also possible to measure the pads switching with the input section removed Using a 30 MHz signal at 20 dBm measure at J 2 using a spectrum analyzer 1 Select Special 63 0 and take a reference on the Spectrum Analyzer straight through 2 Select Special 63 1 The level should go down by 10 dB from 1 PAD 1 3 Select Special 63 2 The level should increase by 20 dB from 1 AMP 4 Select Special 63 4 The level should decrease by 10 dB from 1 PAD 2 5 Select Special 63 5 The level should decrease by 10 dB from 1 PAD 3 If itis necessary to look for power holes in any of the components then sweep the input and monitor the output over the desired frequency range The detector can be checked by going through the detector check as indicated in I nput power detector Gain and Offset Adjustment on page 3 2 HP 8970B Option 020 Service Manual Supplement 5 3 Fault Finding Tips YIG Tuned Oscillator 0955 0630 The3 GHz LPF is board etched and there should be no reason why this would fail If thereis low signal in the through path with Special Function 63 0 then it is either the coupling capacitors or the 2 dB pad is damaged The supply and control connections are shown in Figure 1 1 YIG Tuned Oscillator 0955 0630 The YTO has a range of 4 to 7 GHz but we use over the range 3 910 to 5 947 GHz Check pins 1 2 7 8 and 9 for correct supply voltages Disconnect the Y TO cable from J on the input assem
15. arts List sss 1 1 Block Diagram cce ERR ere a Lee 1 2 Front 970 i dis nies eer ee ede e tee SSS nd Rear 1 3 Material E E isti AA A t e 1 5 Theory of Operation n nn n 2 1 General aao pc ad 2 2 Adjustments aaa a Aaa bat 3 1 General uo a 3 2 Input power detector Gain and Offset Adjustment 3 2 600 MHz SAW Oscillator Frequency 3 3 Board Differences out a e 4 1 Generals 4 2 Microprocessor Board iisas 4 2 20 MHZ IF Assembly 08970 60050 22 4 3 Driver Assembly 08970 60089 4 4 Fault Finding n 5 1 General laicas aaa 5 2 Filter 0953 0024 ii i id 5 2 Input Assembly 08970 60097 or 08970 60125 5 3 YIG Tuned Oscillator 0955 0630 0 2 2 0 0 0 0 66 5 4 Mixer 0955 0635 0 0 0 1 1 ae cnn nn rn asi huq 5 4 ISolator 0960 0638 ironic tenni ETE dari ORT rm
16. bly and connect this to a spectrum analyzer Set the HP 8970B to l Start Frequency 10 MHz 2 Stop Frequency 2047 MHz 3 Step Frequency 20MHz Set the Spectrum Analyzer to l Start Frequency 3 9 GHz 2 Stop Frequency 6 GHz 3 Reference Level 20 dBm 4 Scale 2 dB division Ensure that the signal level measured on the spectrum analyzer is between 14 and 18 5 dB m Note You can monitor the YTO from 4 which is the unused side of the splitter However if you usethis alternative be aware that the levels will be approximately 3 dB lower than when monitoring at J 3 Mixer 0955 0635 The labelling on the schematic in figure 1 may be a little confusing but that is due tothe configuration that the mixer is being used in Theinput signal 10 MHz to 2047 MHz is mixed up to a frequency of 3900 MHz Lower Sideband by and L O varying between 3910 MHz and 5947 MHz The LO port is connected to the YTO 3910 MHz to 5947 MHz ThelF port is connected to the RF input 10 MHz to 2047 MHz TheRF port is a fixed frequency output at 3900 MHz In order for the mixer to work correctly the input level to the L O port should be greater than 10 dBm This can be tested over the frequency range by carrying out the test in section 5 3 but measured at J 5 rather than the YTO output 5 4 HP 8970B Option 020 Service Manual Supplement Fault Finding Tips Isolator 0960 0638 Note J 5 should bethe same level as 4 the other side of the sp
17. e 8568A RF Input 4 Adjust R6 until the signal on the screen is 600 MHz 50 KHz HP 8970B Option 020 Service Manual Supplement 3 3 Adjustments 600 MHz SAW Oscillator Frequency Adjustment 3 4 HP 8970B Option 020 Service Manual Supplement Board Differences Board Differences General General As well as the complete front end being changed there are a number of board differences that need to be documented here Microprocessor Board Thesame part number 08970 60033 is used in both instruments However the firmware is different for the option 20 compared tothe standard Table 4 1 Firmware Part Numbers Options ROM 1 ROM 72 STD 08970 80050 08970 80051 Option 20 08970 80070 08970 80071 4 2 HP 8970B Option 020 Service Manual Supplement Board Differences 20 MHz IF Assembly 08970 60050 20 MHz IF Assembly 08970 60050 The 08970 60050 assembly has been created from the 08970 60003 assembly with the following changes 1 C83 changes from 7 5 pF 0160 3029 to 4 7 pF 0160 3873 2 R8 changes from 110 Q 0757 0402 to 162 2 0757 0405 Figure 4 1 Schematic differences in 08970 60050 15V F1 17 20 MHz BANDPASS FILTEI 15V F1 1 Differences are highlighted with a shaded background HP 8970B Option 020 Service Manual Supplement 4 3 Board Differences Driver Assembly 08970 60089 Driver Assembly 08970 60089 The 08970 60089 assembly has been creat
18. ed from the 08970 60034 assembly with the following changes 1 R25 26 27 R39 R40 and R41 change from 214 2 Q 0699 1911 to 121 0699 3460 2 Q2is deleted and a wireis place between U 33 pin 14 and the base of Q3 Figure 4 2 Schematic differences in 08970 60089 VR2 13V C55 pu 1ST LO DRIVE R24 19 L 30600 1 C28 R25 R26 gt R27 R39 2840 41 1uF 1210 21210 51210 gt 1219 21210 21210 1STLO GND 7 Mi NA MVM NA R57 SEE NOTE 9 3 1000 V F1 C58 6 8 uF 5 VOLT REGULATOR 1 Differences are highlighted with a shaded background 4 4 HP 8970B Option 020 Service Manual Supplement Fault Finding Tips Fault Finding Tips General General The Option 20 front end is relatively easy to fault find because it is a combination of defined RF components Instead of using the noise source it is possible to use a signal generator to inject a signal and then tracethe signal levels through the RF paths to the 300 MHz second IF using a spectrum analyzer It is much easier to do it this way because the signals can be seen on the spectrum analyzer display Filter 0955 0634 The specifications on this part are Table 5 1 2050 MHz Low PassFilter Specifications Frequency Insertion Loss 10 MHz to 2050 MHz 0 5 dB 2 35 GHz to 3 85GHz gt 35 dB 3 85 GHZ to 13 0 GHz 13 0 GHz to 26 5
19. ement Board Details Board Details ing 600 MHz SAW Oscillator Component Layout Draw YSN NI 30H 4 39V Id NI XN 1a d3voa OL HSN14 38 15 sdv31 ANY 0089 JAVNOS FHL OLNI ang 319NV HLIM 1 435 750 39V3 15 20 NO ONILISM 780 40 1 31 SNOT SILVIIONI 100 JHL STYVMdN 22 4 LSAW HO NO SNILISM ANY N33ML3E CNMOG SdW ga JHL HLIM SdW 4 01 NV hO 20 21 1 01 UNVH 919 ANY SIM Z3 IP 212 69 SLAVd QVO Figure 6 1 0313519345 3SIMJ3HIO SSA INN S310N HP 8970B Option 020 Service Manual Supplement 6 2 Board Details Figure 6 2 600 MHz Schematic A18 SAW OSCILLATOR ASSEMBLY 08970 60093 A 608 MHz SAW OSCILLATOR 600 MHz BUFFER 15VF1 T 15VF1 Ton Ik rede RB VA 619 619 01 c2 i 12p los 2N3799 3 an VA m TP a Va Su m mu T ok 5 11k C16 R15 Va CO Va 02 cu 242799 12 162 u ES 1009 fe 1p L2 EDT AUX OUT 33n Va NO LOAD n ND LOAD Ls New R12 3 Lu 46 4
20. is tuned for 3900 MHz This is set at the factory and should not be adjusted TheLO input is 600 MHz but this is multiplied up to 3600 MHz by a X6 circuit The 3600 MHz can be monitored at the LO Monitor port The 600 MHz supplied to the second convertor comes from a 600 MHz SAW Oscillator The frequency is adjusted for 600 MHz 50 KHz The power should be gt 3 dBm 2 2 HP 8970B Option 020 Service Manual Supplement Adjustments Adjustments General General There are 2 adjustments that need to be made 1 Input power detector gain and offset 2 The 600 MHz SAW oscillator frequency adjustment Input power detector Gain and Offset Adjustment Follow the adjustment procedure in section 5 13 of the Adjustments Chapter in the 8970B Service Manual with the following exceptions Figure 3 1 Input detector gain and offset adjustment RF Input Assembly R2GO O R32 1 The input level must be 21 dBm 0 1 dB 2 R32isthe offset adjustment 3 R26is the gain adjustment 3 2 HP 8970B Option 020 Service Manual Supplement Adjustments 600 MHz SAW Oscillator Frequency Adjustment 600 MHz SAW Oscillator Frequency Adjustment Figure 3 2 600 MHz SAW Oscillator Frequency Adjustment 8568A 600 MHZ SAW Oscillator 1 Disconnect the 600 MHz SAW Resonator from the second convertor 600 MHz input 2 On the 8568A Press PRESET CENTRE FREQUENCY 600 MHz SPAN 500 KHz 3 Connect the 600 MHz SAW Resonator to th
21. litter Therefore you can make both YTO and Mixer measurements from J 4 The conversion loss is lt 7dB This is the loss between the IF port and the RF port with the LO gt 10 dBm The best way to dothis is at spot frequencies say 100 MHz steps or if the problem is at a known frequency then doit there The example is for 100 MHz Setup the 8970B Preset Frequency 100 MHz Special 63 0 Set the source for 20 dBm 100 MHz Measure the signal level at J 2 and record it Connect the mixer in place and measurethe signal at the RF port This will be at 3900 MHz The difference between the 2 signal levels should beless than 7 dB Isolator 0960 0638 This device will improve the match looking back from the 4 GHz low pass filter Theinsertion loss will be between 1 dB and 1 2 dB depending on the temperature This can be measured with a network analyzer a spectrum analyzer and tracking generator or a spectrum analyzer and sweeper The operating frequency of the isolator is 2 to 7 GH but we need only check it 50 MHz either side of 3900 M Hz 4 5 GHz Low Pass Filter 9135 0169 The specifications on this part are shown in Table 5 2 These specifications can be verified by using a network analyzer a spectrum analyzer with a tracking generator or a spectrum analyzer with a sweeper Table 5 2 4500 MHz Filter Specifications Frequency Insertion Loss DC to 4050 MHz 0 5 dB DC to 4500 MHz lt 1 d
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