[Milsurplus] Another BC-348 question

[jcoward5452 at aol.com]

Ralph,
 Not normal.
  Oscillator instability due to mechanical movement can be caused by a 
tube with its internal structure coming undone(probably unlikely but 
similar to microphonic tubes) or one or more air padder condensers 
(APC) on the verge of failure.These air variables have been known to 
fail when the retainer (looks like a nut on the end of the shaft) 
cracks or just gets loose and the cap rotor and stator start to become 
close friends.I've had that happen and it's a bear to get into those RF 
boxes but it is do-able with patience.No coffee!Also I had one -348 
that had a backlash problem in the main tuning cap that I was able to 
improve upon but never got it really fixed.Sold that one at a local 
flea for peanuts(the peanuts were locally grown and delicious!).That 
can cause similar issues with the local oscillator too.
Good luck,
Jay KE6PPF

-----Original Message-----
From: ramcam at magma.ca
To: milsurplus at mailman.qth.net
Sent: Thu, 21 Sep 2006 2:52 PM
Subject: [Milsurplus] Another BC-348 question

Do any list users have experience operating the 348 in an aircraft, on 
cw? Mine
has some decided instability when the chassis is moved even slightly. I 
imagine
this could be very distracting to the opr.

Is this normal? Is there a fix? Voltage regulator seems to be working 
fine.

This may have been asnwered in previous lists but I missed it.

Thanks

Ralph Ve3BBM
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