Re: No receive or transmit
Looks like there is no data from the cpu. Check folowing points:
- Check Q2026 for 5 volt on pin 4, on HF on reception,
- Check Q2033 for 5 volt on pin 4, on HF on transmision,
- Check Q2023 for 5 volt on pin 4, on UHF on reception,
- Check Q2024 for 5 volt on pin 4, on UHF on transmision,
- Check Q2032 for 5 volt on pin 4, on VHF on reception,
- Check Q2025 for 5 volt on pin 4, on VHF on transmision,
Check the connection between J2003 PLL board, and J1025 AF-CTRL-UNIT,
Check if ic Q1119 (BU4081BF) is oke
?
> Check the "VHF-VCO VCV check" and the "UHF-VCO VCV check". If they check ok, then your REF is ok.
> Otherwise check REF, and check if you have output of both PLL's Q2040 and Q2044 pin9.
>?
> 108.000 ? ? ? ? .004 vDC
> 134.995 ? ? ? ?.011 ? vDC
> 140.000 ? ? ? ?.011 ? vDC
> 173.995 ? ? ? ?.011 ? vDC
>?
> I could not locate Q2040 and Q2044 on the PLL board to check them. I located them on the block diagram and schematic. Looking at the block diagram I can only assume they are under one of the four anodized covers on the PLL > > board.?
>?
> Check the voltages on J2001:
> 1 gnd <Ground is good>
> 2 8V. ?<7.90 v DC>
> 3 5V ? <4.95 v DC>
?>?
> J2002:
> 1 gnd ?<Ground is good>
> 2 HR8 8V on reception HF <0>
> 3 HT8 8V on transmit HF ? <.004 vDC>
> 4 VR8 8V on reception VHF <0>
> 5 VT8 8V on transmit VHF. <.004 vDC>
> 6 UR8 8V on reception UHF <0>
> 7 UT8 8V on transmit UHF. ?<0>
>?
> I very much appreciate the guidance on this issue and am certainly going further in depth on this radio attempting to solve this issue. It is a great learning experience for me actually troubleshooting a problem of this > > > level. ?I have replaced components on my other radios but usually something straightforward such as a filter on my Kenwood mobile radio. ?
>?
> 73,
>?
> David AL5M
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
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Re: No receive or transmit
I would continue there will only be one fault.
73
Andrew
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On 25 Aug 2024, 04:38, at 04:38, "David A Rutledge via groups.io" <al5m@...> wrote: I recently picked up a non-working 847 to replace the display on mine.
The numbers on my 847 were losing some of the segments but the
inoperable 847 had a good display. It was an easy swap and now my 847
has a good display. The OP I bought the salvage 847 from told me he had
purchased it from an estate sale but the rig was 'deaf' when he
connected an antenna and powered it up. ?I hooked it up to a watt meter
and dummy load and the rig will not transmit on any band. I started the
alignment procedure and discovered the PLL adjustments showed minimal
voltage (.022 volts) at TP20001 and would only change a few thousands
when I adjusted T2001 through T2005.
I am wondering where to go at this point to start troubleshooting this
issue. Is it worth pursuing trying to repair this non-working rig or
put it on the shelf to salvage parts from in the future?
73,
--
David Rutledge
AL5M
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Re: No receive or transmit
Check the voltages on J2001:
1 gnd
2 8V
3 5V
?
J2002:
1 gnd
2 HR8 8V on reception HF
3 HT8 8V on transmit HF
4 VR8 8V on reception VHF
5 VT8 8V on transmit VHF
6 UR8 8V on reception UHF?
7 UT8 8V on transmit UHF
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
|
Re: No receive or transmit
Check the "VHF-VCO VCV check" and the "UHF-VCO VCV check". If they check ok, then your REF is ok.
Otherwise check REF, and check if you have output of both PLL's Q2040 and Q2044 pin9.
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
|
I recently picked up a non-working 847 to replace the display on mine. The numbers on my 847 were losing some of the segments but the inoperable 847 had a good display. It was an easy swap and now my 847 has a good display. The OP I bought the salvage 847 from told me he had purchased it from an estate sale but the rig was 'deaf' when he connected an antenna and powered it up. ?I hooked it up to a watt meter and dummy load and the rig will not transmit on any band. I started the alignment procedure and discovered the PLL adjustments showed minimal voltage (.022 volts) at TP20001 and would only change a few thousands when I adjusted T2001 through T2005. ?
?
I am wondering where to go at this point to start troubleshooting this issue. Is it worth pursuing trying to repair this non-working rig or put it on the shelf to salvage parts from in the future?
73,?
--
David Rutledge
AL5M
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Will do this saturday, I'll let you know. Thanks
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--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
|
Put the transmitter in SSB.
Mic gain 12 o clock position.
Inject a 1KHz tone at 3mv level to the MIC jack (pin 8 = mic input, pin 7 = ground)
Use a old amplified computer speaker, to trace the 1KHz tone, at the points below:
- Q1053 (M5207L01) pin 4,
- With a DC voltmeter, Q1053 pin 3, must be around 2.5 Volts, and changing when rotating MIC Gain,
- Q1053 pin 2, amplitude changes when rotating MIC Gain,
- Q1081 (BU4053BCF) pin 14,
- Q1038 (NJM2902M) pin 7,
- Q1038 (NJM2902M) pin 8,
- Q1081 (BU4053BCF) pin 15,
Please let us know your findings.
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
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Thank you. I also notice that at the ssb there is no signal, of course im only using a osciloscope
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The ic is a m5207L01 that is a stereo volume controller. PIN2 = output, PIN3 = control 0-5 volt, PIN4 = input.
The datasheet can be found here
?
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
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These chips were are current mirrors, you will not see the mic signal around here, look upstream towards the modulator and SSB filter.
73
Andrew
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On 21 Aug 2024, 03:57, at 03:57, "HI8RMQ via groups.io" <rafael_mota@...> wrote: This is the preamp area, the left top ic manages audio input into
hf,vhf,and uhf.
Part is not clearly readable, but I think is Q1063 or Q1053.
Yellow line is the traced path from 1Khz audio input from mic.
Blue is the command data to control the audio to be output in the red
line.
Red line measures noise, not the 1Khz signal as I think it should.
Maybe a more experienced mate could observer something from this.
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This is the preamp area, the left top ic manages audio input into hf,vhf,and uhf.
Part is not clearly readable, but I think is Q1063 or Q1053.
?
Yellow line is the traced path from 1Khz audio input from mic.
Blue is the command data to control the audio to be output in the red line.
Red line measures noise, not the 1Khz signal as I think it should.
Maybe a more experienced mate could observer something from this.
?
?
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HI8RMQ if you want us to point you at the possible fault. You have to gif answers to our questions consistently. And gif answers to what you are asked.?
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Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
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Please just make a video and post it as private on YouTube. Folks can then see exactly what’s going on and broach a comment.
De Spence G5STO Sent while portable! please excuse typos.
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On 20 Aug 2024, at 12:30, Andy Bosworth via groups.io <sidthepop@...> wrote:
? Great, if power output is ok on FM and CW then your PA is working. Do you have the same low SSB on VHF? Where were you feeding audio in to the rear? Which port on the back? Finally, what test equipment do you have? Very low audio, so SSB on HF is at much 3W.
Powers on other modes all fine, AM, FM, CW, but theres no audio noticeable on FM or AM.
Just happens on HF.
?
?
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Great, if power output is ok on FM and CW then your PA is working. Do you have the same low SSB on VHF? Where were you feeding audio in to the rear? Which port on the back? Finally, what test equipment do you have?
Very low audio, so SSB on HF is at much 3W.
Powers on other modes all fine, AM, FM, CW, but theres no audio noticeable on FM or AM.
Just happens on HF.
?
?
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Very low audio, so SSB on HF is at much 3W.
Powers on other modes all fine, AM, FM, CW, but theres no audio noticeable on FM or AM.
Just happens on HF.
?
?
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Further up the discussion he stated 100 watts FM on HF, so PA is fine. Perhaps the OP could clarify if any power on AM, CW and FM on HF, just so we are not getting confused.
So no power in HF in FM mode? Then the fault is in the HF PA section, Q3002, or the preceding BPF.
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
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So no power in HF in FM mode? Then the fault is in the HF PA section, Q3002, or the preceding BPF.
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
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Correct. The modulation in HF is very very low, talking very loud may give 3 or 4 w
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Correct me please if i am wrong.
The TS says that there is no modulation in phone and in digital mode, on HF?
There is modulation on 2 meter, and 70 centimeter, in all modulation modes, digital and phone?
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Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
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Andrew Lenton
Spence G5STO
Andy Bosworth