开云体育

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

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.

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.

Looks like there is no data from the cpu. Check folowing points:

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.