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Philco model 70 rebuild - by Tim P.
#88

Ok, I dont want to get my hopes up just yet, but, I bypassed (subbed) the 70 ohm bias resistor to ground. I am not getting the flutcuations I had before. I do get fluctuations in the current draw, however, now they are smooth and slight. I reconnected the original resistor, and almost immediatly I noted the erratic fluctuations in current draw and volume. I have the sub back in. I am going to test this off and on for the next week before I shout victory or 'onward'...

I have tapped and swapped tubes. I dont think it is the socket. I dont get any change when I move the tube around. They seem good and tight in the sockets. I am getting the same thing on 2 different sockets, with 2 different tubes. The screen and cathode voltages are the only thing these 2 have in common.

Something else I noted is a wire 'whisker' between the open section of the bias resistor between points F & G. I read aprox 500k on this, and it is not on the diagram. Anyway, I will fire back if this has licked this irritating problem or not. Thanks for the advice.

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44


Messages In This Thread
Philco model 70 rebuild - by Tim P. - by TV MAN - 01-29-2014, 11:46 AM
RE: Philco model 70 rebuild - by Tim P. - by TV MAN - 05-05-2014, 11:03 PM



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