[AMRadio] R-388 PTO info needed

John Lawson jpl15 at panix.com
Sun Dec 25 16:47:15 EST 2005

   Further to my Xmas Eve Scrooge Radio Post - I have discovered that no 
signals of any kind appear on the PTO output cable when isolated from the 
mixer tube, and injecting the correct frequency into that pin of the mixer 
(from my bench oscillator) restores the radio to operation.

  So, of course, the PTO has quit, and the tubes (AFAIK) are good - but 
next I'll replace them with a couple that test out at better than 70% Gm - 
somehow I think that's not going to be the Problem.

   If anyone within the sound of my keyboard has any experience actually 
repairing this series of PTO - it's a Collins 70E-15 ser. M1751 - I'm 
trying to guage whether I should spend the time to dredge it out and fix 
it - or (since the front panel needs to be refinished) I would be better 
served by just bundling it off to someone and letting an expert refurb the 
radio. I do plan to keep it, it's my Fave Reciever - for Ham and SWL -

  Also: if you have a quote to perform the above, lemme know ASAP - I'm 
'motivated' as they say in Real Estate.

  Cheers and Best of the Season!

John  KB6SCO

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