[R-390] Help! R-390 Meltdown

[Rick Popovich]

Good morning all,

I'm having a problem that I hope someone out there has also encountered and
can share their knowledge and experience and hopefully the fix.

I have been working on an R-390 that I acquired as a "parts rig". It was
only missing a power supply so I substituted a P/S that I had in my pile and
fired it up just the see what would happen. To my surprise it actually
worked.

After using it off and on as a test mule it quit working and luckily I was
right around the corner and was able to shut it off as smoke started to come
out of the RF deck. While I had never removed an RF deck before I dusted off
the manual and pulled it out of the receiver.
Since I saw where the smoke was coming from it was easy to spot the failed
component - it was R 220 which I've traced to part of the 3rd IF circuit.

Assuming it was probably just a resistor that was tired & out of tolerance I
replaced it and put her back together. No sooner did I get it back together
and fire her up when up in smoke she went - same problem.

I have stated to check voltages etc. and have yet to find what is causing
this. HELP!

Any experience/insight or solution would be appreciated.

Tnx, Rick

rickp at fndmail.csus.edu