[Milsurplus] Test your repair skills

Mon, 23 Jun 2003 12:08:23 -0600

I had an APC type cap fail in the RF "box" of a BC-348.The little retaining "nut" on the shaft split so the rotor shorted to the stator due to the spring on the other end of the rotor.It wasn't too difficult to track down but was I surprised by the failure mode.
 Jay

-----Original Message-----
From: Kenneth G. Gordon [mailto:[email protected]]
Sent: Monday, June 23, 2003 10:44 AM
To: [email protected]
Cc: [email protected]
Subject: Re: [Milsurplus] Test your repair skills

1) Hidden corrosion in and/or around the VFO tuning capacitor.

2) A bad silver mica shunting capacitor.

3) A bad NPO frequency-set tuning capacitor.

I had the indentical problem which you are having with a 
Heathkit VF-1. It would jump frequency periodically for no 
apparent reason. Tapping on the case, or twisting the chassis 
momentarily fixed it. It took me a year to track it down. It was a 
defective NPO silver mica or ceramic frequency-set tuning 
capacitor, one of those screwdriver adjusted 3 -30 pfd types,  
which was in parallel with the main-tuning cap.

After I replaced it, I had no further problems....and, to my mind, 
it was the last thing I would have suspected.

Ken Gordon W7EKB
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