[NJARC] Advice Needed:

[TrainBee at aol.com]

Happy New Year Joe,
 
    I have not seen this condition, yet.  I  rebuilt a 41-295 several years 
ago for a friend.  It had a great full  sound.  It was like having your own 
voice of the theatre in your  home.  A thought I had regarding the transformer 
would be to put in a small  pancake fan.  I don't see how it would hurt to help 
dissipate some of the  heat.  
 
Joe Devonshire - KC2FIQ
 
 
 
In a message dated 1/1/2008 7:56:34 A.M. Eastern Standard Time,  
n3ibx at verizon.net writes:
Visit our web site - See  http://www.njarc.org
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Happy  New Year and Hello to  All,
I finally got a "roundtuit" and worked on one of the forgotten orpans of a  
console radio, namely a Philco 41-290 I picked up at one of our club auctions  
sometime ago. Besides doing a complete recap, needed tube replacement, even  
replaced the audio output transformer, etc etc I noticed the power transformer  
coughed up most of it's original insulating tar on the wooden base it sits 
on.  Having previously read somewhere that Philco's are notorious for having bad 
 power transformers, I approached powering the set up with a bit of caution. 
I  first pulled the rectifier (#84 tube) and powered the set up on a variac to 
see  if teh transformer, or anything else would smoke up. Nothing. Good, on 
to the  next step. I then ramped up the AC voltage again with the rectifier 
tube  installed. (as a sidenote, the original rectifier tube didn't have filament 
 continuity - a bad sign that it may have been taken out by the transformer 
or  other components) and still no smoke. I then went through and did a total 
paper  and electrolytic capacitor replacement, etc etc, and the set came to 
life.  

Needless to say I was very pleased to now have another good player in my  
stable of old consoles. I'd like to add that the audio sounds terrific from it's  
push-pull 41 output into a 14" speaker and correct replacement audio output  
transformer. 
My question is what do I dfo with the power transformer? It  does run warm 
after playing it for an hour or so. I suspect some of the heat  being generated 
is by convection from the tubes that surround it. I'm just  concerned that 
it's inevitable that it'll eventually short out or become  defective; unless I 
"re-pot" the transformer with some sort of insulating  material. 

Has anyone else in our group come across a situation like  this? If so, what 
did you use to repot the transformer? I was thinking of  silicone RTV, but due 
to it's curing properties I don't know if it would be a  suitable medium to 
use. Should I just leave it alone and hope for the best?  Again, any advice 
will be greatly appreciated.

Many thanks in advance for  any advice, and a very Happy new year to all. May 
2008 bring you more radio that  glow in the dark!

Joe Cro  N3IBX

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