[MRCA] A surprise when I opened my R-392

[David Olean]

Hello J. McVey

I think you missed the F.T.A. part, but that's OK.  The audio, IF and 
Calibrator assy came out quite easily.  I started checking some 
capacitors in the audio assy. A coupe of Vitamin Q caps tested 100%. 
Then I got to some GE 0.1 MFD ones. Out of five units, all were leaky. 
My ESR tester said 42 ohms ESR and about 6% loss. I hooked them up to a 
DC supply and huge amounts of DC leaked thru. With 100 VDC on one side 
of the cap, I saw 45 volts on the opposite side with my Fluke DVM.  I 
chucked em all, and now the audio stage is quiet and working just fine.

Dave

On 12/19/2019 12:10 AM, J Mcvey wrote:
> Yeah, they call them "modules" . Modules are supposed to make 
> servicing easier. It's just not the case with the R392.
> You have disassemble the whole radio to get them out!
> No wonder your brain hurt.
> Mine did too after pulling the oscillator "module".
>
> Did what I had to do and put it back together, I decided that pulling 
> the others "just to check them" would be more work that it was worth.
>
>
>
>
> On Wednesday, December 18, 2019, 6:38:48 PM EST, David Olean 
> <k1whs at metrocast.net> wrote:
>
>
> See the photo attached. I had an audio section in my R-392 that needed
> work. (The whole thing needed work!)  I was getting leaky capacitor
> sounds in the audio, so I took the modules out of the R-392 and was very
> surprised to see the "note" written in blue magic marker. Obviously the
> repair was done during the Vietnam war.  It brought back a lot of
> memories from my time in the draftee Army during the late 60's . (I was
> not a draftee)
>
> As for the R-392, it is getting better. Someone had messed up the
> synchronization of the gear train, Veeder Root counter, the PTO etc.  I
> went back to the beginning and  re set the counter, checked all the cams
> and tweaked them back. Then I adjusted the Oldham coupler so that the
> PTO would read correctly.  When I was done, my brain hurt!
>
> Dave K1WHS
>
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