11-29-2010, 10:33 PM
Hello Philco collector friends !!
I am new here at the Philco Phorum, and I have a peculiar probelm with a Philco 39 - 55 radio set! The radio did not play originally and needed a lot of new parts like capacitors and resistors that that were either leaky or migrated way out of 20 percent tolarance (resistors). The set did not have an original output transformer when I acquired the set, I temporarily installed a transformer that matched the impedance values of the 42 output tubes to get the set going,
I was succesfull at this part, now here comes the problem, I have just installed an original type output transformer with the feedback tap (I think) connected to the bottom of the volume control.
The set plays BUT when i turn the tone control to max treble I get a high pitch feedback, then as I go toward BASS the feedback disappears and set sounds normal, then when the control is at max BASS a low frequency feed back occurs!!
My question is does someone have the color code of the transformer wires on both primary and secondary sides? What wire exactly, is the negative feedback wire on the secondary? I assume it is the wire that has a green tracer on it? and what two wires go to the speaker? is it the white colored one and the solid green one? If i ground out the bottom connection of the volume control the set works O.K. but at a little louder setting of the volume control ! the remote control section was reworked also and seems to work O.K. including the stepper relays and contact wiper assemblies after a little cleaning and light relubing. I think my problem is somewhere in the wiring of the original type output transformer somewhere along the line !! Thanks for any help in advance -------------- John A Bellas
I am new here at the Philco Phorum, and I have a peculiar probelm with a Philco 39 - 55 radio set! The radio did not play originally and needed a lot of new parts like capacitors and resistors that that were either leaky or migrated way out of 20 percent tolarance (resistors). The set did not have an original output transformer when I acquired the set, I temporarily installed a transformer that matched the impedance values of the 42 output tubes to get the set going,
I was succesfull at this part, now here comes the problem, I have just installed an original type output transformer with the feedback tap (I think) connected to the bottom of the volume control.
The set plays BUT when i turn the tone control to max treble I get a high pitch feedback, then as I go toward BASS the feedback disappears and set sounds normal, then when the control is at max BASS a low frequency feed back occurs!!
My question is does someone have the color code of the transformer wires on both primary and secondary sides? What wire exactly, is the negative feedback wire on the secondary? I assume it is the wire that has a green tracer on it? and what two wires go to the speaker? is it the white colored one and the solid green one? If i ground out the bottom connection of the volume control the set works O.K. but at a little louder setting of the volume control ! the remote control section was reworked also and seems to work O.K. including the stepper relays and contact wiper assemblies after a little cleaning and light relubing. I think my problem is somewhere in the wiring of the original type output transformer somewhere along the line !! Thanks for any help in advance -------------- John A Bellas
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