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- From: wa2ise@cbnewsb.cb.att.com (robert.f.casey)
- Newsgroups: rec.radio.amateur.misc
- Subject: TS520 service notes
- Keywords: troubleshoot
- Message-ID: <1991Nov24.170347.29597@cbfsb.att.com>
- Date: 24 Nov 91 17:03:47 GMT
- Sender: news@cbfsb.att.com
- Organization: AT&T Bell Laboratories
- Lines: 137
-
-
- copied from packet:
- Msg# TSF Size #Rd Date Time From MsgID To
- 8166 BF 4244 0 24-Nov 0152 KD2EJ 27230_WB2QJA ALL@ALLBBS ()
- Service notes on TS-520 10-21-77
-
- TRANSMITTER
-
- 1. No switching of final relay: Bad Q8 on X54-0001-00 2SA562Y.
-
- 2. No drive: C3 100pf in final box is cold soldered.
-
- 3. Low output: Check the plate load cap for touching plates.
-
- 4. 3.5 MHz low output: Replace burned 47pf 3KV at load wafer.
-
- 5. No TX: Final choke burned out in final VOX L8.
-
- 6. No RX or TX: Bad common amp. Q1 3SK35GR in IF unit X48-1060-00.
-
- 7. No ACC: No plate current Q2 3SK41 If unit X48-1060-00.
-
- 8. No TX relay: Q8 2SA562Y on VOX unit. Also R18 1K resistor relay
- control.
-
- 9. No TX or RX: Check 9 volt terminal on FIX AVR (X43-1100-00) is loose.
-
- 10. No CW TX: Bad 9 volt regulator. Check D3 WZ061 on X43-1100-00.
-
- 11. No TX: Solder touch between TIF and key terminal on X44-1080-00.
-
- 12. No drive to TX: Check RL1 on GEN unit, small reed relay (X52-0010-
- 01).
- 13. No ALC meter action on 10 meters: This is normal for TS-520.
-
- 14. CW chirp: Q4 2SA606L on Fix channel AVR X43-1100-00.
-
- 15. ALC meter to maximum when TX: RFI terminal at X44-1080-00 is not
- soldered.
-
- 16. No TX output: 82pf 3KV in final is burned.
-
- 17. No TX output: Q3 on RF unit 3SK41 X44-1080-00.
-
- 18. No bias: 10 ohm cathode resistors burned in final VOX.
-
- 19. No drive or TX output: R70-71 RF unit, R5 Rectifier unit.
-
- 20. No VOX: Q8 in VOX unit X54-0001-00.
-
- 21. No TX: 12BY7 is bad. Shorts and burns out. R71 and 70.
-
- 22. No carrier output: Q1 on Carrier X50-0009-01.
-
- 23. No drive - no screen voltage: R5 470 ohm open on rectifier X43-1090-
- 00.
-
- 24. No drive - no ALC: Q2 3SK35Y IF unit. Q3 3SK41L RF unit.
-
- 25. No RF output: C13 0.04uf at pin 1 of S2001A is bad.
-
- 26. Low mic gain: Q1 2SC1000 on Gen unit.
-
- 27. No TX: Misconnection of brown wire after installation of CW filter.
-
- RECEIVER
-
- 1. Low Sensitivity: Touching RLT and 9V at function switch.
-
- 2. Receiver sensitivity: No -6v at AVR: Q8 2SC735 on X43-1100-00 is
- bad.
-
- 3. Frequency Shift: Bad carreir Xtal 3395 on carrier unit.
-
- 4. VFO drift: C6 22pf, VFO unit.
-
- 5. No receive: Bad Q4, 3rd IF amp 3SK35GR on X48-1060-00.
-
- 6. Receiver sensitivity and bias current jump, -6v unstable: T1
- oscillator transformer for -6v is bad on X43-1100-00.
-
- 7. Erratic AGC action: C11 100uf 16Von X431100-00. Fix channel AVR is
- bad.
-
- 8. Frequency shift when warmed up: Q1 in VFO 3SK22GR.
-
- 9. No RX or TX: If unit C59 touch to T12 IF transformer.
-
- 10. Receiver noise: Q5 3SK35Y X44-1080-00.
-
- 11. Receiver sensitivity down: NBI terminal is pulled loose. Receiver at
- IF board.
-
- 12. No S meter reading and RF gain CCW. No meter deflection: Q3 on IF
- unit. Q5 on RF unit.
-
- 13. VFO frequency jumped: There is loose tension inside VFO.
-
- 14. VFO frequency shift: Cold solder of VFO output lead to VFO output
- socket.
-
- 15. Blows fuse when first on: Check Q1 and Q2 DC-DC converter transistor.
- One is possibly shorted.
-
- 16. Noise blanker inoperative: R6 4.7K resistor is broken at Q2 on X54-
- 1080-10.
-
- 17. Loud audio squeal: Q4 3SB473 on X49-0008-01 shorted.
-
- 18. Low receiver sensitivity: Diode D4 1S1587 on RF unit.
-
- 19. VFO intermittant: Wire to L1 in VFO is not soldered.
-
- 20. No receive: Q4 3SK35Y, Q5 3SK35GR on RF unit.
-
- 21. No receive: Q9 3SK35GR on IF unit.
-
- 22. Hash noise in receiver: Q3 on RF unit 3SK41.
-
- 23. Blows fuse: C31 power supply is shorted, 100uf 500v. Also check
- associated diode D3, D4.
-
- 24. No RX on all bands: WWV switch is broken or a wire is loose or not
- soldered.
-
- 25. Receiver sensitivity: Q5 on RF amp 3SK35Y.
-
- 26. Receiver sensitivity: NBO terminal on X48-1060-00 is loose.
-
- 27. Low audio: Check for purple wire touch to ground at 12 pin connector
- in rear panel.
-
- (c) 102177TKC
- Copyrighted Kenwood U.S.A. Corp.
- Relayed with permmission from Kenwood U.S.A.
- ---------------------------------------------------------------------------
- I haven't tried or verified this, proceed at your own risk. WA2ISE
-
-
- From: wa2ise@cbnewsb.cb.att.com (robert.f.casey)
- Newsgroups: rec.radio.amateur.misc
- #Subject: TS520S service note: -6v supply
- Message-ID: <1991Nov30.040656.19491@cbfsb.att.com>
- Keywords: ts520
- Sender: news@cbfsb.att.com
- Organization: AT&T Bell Laboratories
- Date: Sat, 30 Nov 1991 04:06:56 GMT
- Lines: 27
-
-
- copied from packet:
- SB-043
-
- TS-520S -6v Supply Failure 8-9-79
-
- When troubleshooting a TS-520S, check all power supply voltages, including
- the -6v DC supply. Symptoms such as dead, blown 2A DC fuse and now dead,
- low RX, no TX, or similar may occur after switching between 80 and 40M.
-
- Cause of failure may be traced to an intermittent shorting between the 14v
- dc and -6 dc supplies as the band switch is rotated between 40 and 80
- meters. This will weaken or destroy D8, a 6v zener on the FIX CH AVR unit.
- To prevent repeat failures, break the White lead and install a 22 K ohm 1/2
- watt resistor at the bandswitch S5-6, between the -6v supply line and
- switch terminal. An of course replace D8 on the FIX CH AVR unit, X43-1100-
- 00
-
- New Part: 22 k ohm 1/2 W carbon resistor
-
- Please annotate your service manual.
-
- JEB/yn
- (c) 8979TKC
- COPYRIGHTED KENWOOD U.S.A.
- ==========================================================================
- Note: I haven't tried or verified this, proceed at your own risk. WA2ISE
-
-
- From: wa2ise@cbnewsb.cb.att.com (robert.f.casey)
- Newsgroups: rec.radio.amateur.misc
- #Subject: TS520/S service note on CW mode
- Keywords: ts520
- Message-ID: <1991Nov30.041026.19604@cbfsb.att.com>
- Date: 30 Nov 91 04:10:26 GMT
- Sender: news@cbfsb.att.com
- Organization: AT&T Bell Laboratories
- Lines: 20
-
-
- copied from packet:
- SB-046
-
- TS-520/520S CW Frequency Shift 8-6-79
-
- Reports of intermittent frequency shift during CW operation, on the order
- of a few hundred cycles, may be traced directly to the Carrier Unit.
-
- On the Carrier unit X50-0009-01, install a ground lead of #18 tinned wire
- or similar, between the cases of T1 transformer and X3, the LSB XTAL.
- Recheck frequencies after installing this ground lead.
-
- Please annotate your service manual.
-
- JEB/yn
- (c) 8679TKC
- COPYRIGHTED KENWOOD U.S.A. CORP.
- ===========================================================================
- Note: I haven't tried or verified this, proceed at your own risk. WA2ISE
-
-
-
- Copied from the QRZ! Windows Ham Radio CDROM
-
-