[ARC5] Working on the AN/ARC-2

[Kenneth G. Gordon]

On 16 Mar 2014 at 9:05, David Stinson wrote:

> Having a problem with the Collins AN/ARC-2 transceiver.

I have one of those too. I would be very glad to hear your experiences with 
yours.

> On transmit, the PTO would drift up 1 KC+ over a few seconds.
> First theory was that one or more caps on the various power 
> busses
> were leaking, dragging the buss down.
> 
>  Finally was able to get it on the bench last night and did find 
> some.
> The 260V buss that feeds the PTO is filtered by a large 5.5 uFd
> oil-filled cap.  This tested "open" on my ZM-11, until I 
> accidently
> "popped" it with about 750V from the tester.   Now it tests Good
> and I can't make it fail again, so I put it back in the circuit.
> Anyone got a idea on that?

Hmmm....poorly soldered or otherwise poorly connected internal connection? 
Corroded terminals?
 
> I also found two very familiar and very bad 5 uFd electrolytics
> that were in the hash filter for the A+ buss into the dynamotor 
> primary.

Ah! Thanks for the pointer.

> A bit surprised to see Collins using an A.R.C. Type-12 part:
> http://home.netcom.com/~arc5/IMG_2904.JPG
> 
> All the other filter caps on the 260V buss check OK.
> After "fixing" the 5.5 uFd, the PTO only drifts about 400 cycles
> on key-down, so that was part of it.
> Going to disable each stage on that buss one-by-one
> until I find the "bad boy."
> 
> Working well enough now that I was able to work
> W1AW/7 on 3885 KC AM with it last night.
> And I beat-out a local friend in the pile-up
> with his Ground-Pounder BC-610E... heh heh!

Hee hee! Good on ya! :-)

Ken W7EKB