05-04-2015, 03:56 PM
Hello, all.
Well, I couldn't resist picking up another radio. It's a 42-PT-93. The schematics are located here:
http://www.nostalgiaair.org/PagesByModel...014176.pdf
I did the usual recap and replaced the resistors but I am not getting any sound from it but the tubes and dial lamp light up. The tubes are also good. I tried touching the center tab of the volume control but don't get any hum. I replaced the volume control but still don't get any hum but the speaker makes a pop when I connect it to a 9v battery. When I tried taking ohm readings on the 50L6GT, I accidentally touched both pin 2 and 3 at the same time and got a loud hum from the speaker.
I tried taking readings on the loctals by connecting the negative of my digital multimeter to ground, turning the volume control to full, and touching the positive to each pin but I must be doing something wrong because I don't get readings on any of them.
I measured the oscillator coil from ground with the volume turned all the way up and got these readings (not sure if I have the pins correct, though):
Pin 1 - .7
Pin 2 - no reading (DMM doesn't change if that makes sense)
Pin 3 - no reading
Pin 4 - 7.1
Pin 5 - 6.9
I read somewhere on this forum how to rewind this type of oscillator but I can't find it now. If someone could point me in the right direction, I'd appreciate it. A picture of it is attached.
Finally, the case has a built in loop antenna. The two ends were unattached to anything when I got it and I can't figure out where one end goes. I know one goes to the tuning condenser but where does the other end attach?
Any help is greatly appreciated.
Dave
Well, I couldn't resist picking up another radio. It's a 42-PT-93. The schematics are located here:
http://www.nostalgiaair.org/PagesByModel...014176.pdf
I did the usual recap and replaced the resistors but I am not getting any sound from it but the tubes and dial lamp light up. The tubes are also good. I tried touching the center tab of the volume control but don't get any hum. I replaced the volume control but still don't get any hum but the speaker makes a pop when I connect it to a 9v battery. When I tried taking ohm readings on the 50L6GT, I accidentally touched both pin 2 and 3 at the same time and got a loud hum from the speaker.
I tried taking readings on the loctals by connecting the negative of my digital multimeter to ground, turning the volume control to full, and touching the positive to each pin but I must be doing something wrong because I don't get readings on any of them.
I measured the oscillator coil from ground with the volume turned all the way up and got these readings (not sure if I have the pins correct, though):
Pin 1 - .7
Pin 2 - no reading (DMM doesn't change if that makes sense)
Pin 3 - no reading
Pin 4 - 7.1
Pin 5 - 6.9
I read somewhere on this forum how to rewind this type of oscillator but I can't find it now. If someone could point me in the right direction, I'd appreciate it. A picture of it is attached.
Finally, the case has a built in loop antenna. The two ends were unattached to anything when I got it and I can't figure out where one end goes. I know one goes to the tuning condenser but where does the other end attach?
Any help is greatly appreciated.
Dave