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511 series AF transformers
#1

After replacing a burned out 71A tube I was getting one strong channel but no volume control. I figured I'd recap it and see what I got. While waiting for the new caps to arrive I went through the chassis more thoroughly and found that the output choke was taken out of the circuit with the speaker connected directly to the 71A and worse, the 2 AF transformers (#3077) appear to be open... I doubt I'll be able to find replacements and I don't want to put a lot of money into it. Is it possible to rewind these myself or use some modern replacements?
#2

Hi

While these can be rewound, modern replacements are available for the audio interstage transformers from a few sources. You will want transformers with a 1:3 ratio.

Or, you could change the audio interstage transformers to resistance coupling. Details here:
http://www.philcoradio.com/tech/audio.htm
Scroll down to "Modification C."

--
Ron Ramirez
Ferdinand IN
#3

Thanks Ron, I will try the resistance coupling if I can't find an appropriate match. This may be a silly question but, could I use a 110v to 36v power transformer (1:3 ratio) as a substitute? Also what kind of current rating should be used?




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