09-11-2025, 08:22 PM
I managed to re-wind the coil. Didn't come out too badly. I removed the old winding along with the celluloid material, cleaned it with rubbing alcohol, and baked it in the oven at 200 for about 25 minutes. Then, I used green masking tape as an insulator, and I added roughly 100 turns of AWG 34 copper wire on it, and sprayed it with clear lacquer to protect it.
After reinstalling it in the radio I still had no reception. I used a little Emerson transistor radio to determine the oscillator was running. Trying to feed a 175kc signal into the antenna terminal resulted in a barely audible sound from the radio. I checked the voltages, and figured out that all of the screens in the front end were missing voltages - which they get through a 25k resistor, which, I had connected to the wrong terminal after redoing a bakelite block. Ugh! After fixing that, it plays.
A couple things I noticed - it seems very sensitive and selective for an early radio. Tons of volume, but sound quality is only ok - I'm thinking due to the primitive speaker with a stiff spider. Also, voltages are all high - probably because of the replacement transformer. B+ at the rectifier is 310v, so I need to find a way to reduce that. I also noticed (how I missed this before, I have no idea), all tubes except for the 47 are 6.3v equivalents of the originals, obviously whoever worked on it had trouble finding a transformer with a 2.5v winding. I don't blame them for converting it over.
I tried to adjust the oscillator at 600kc, and found the adjustment didn't do much. I might just leave it, it works ok. I also really need to get grommets for the tuning capacitor, it's completely loose.
After reinstalling it in the radio I still had no reception. I used a little Emerson transistor radio to determine the oscillator was running. Trying to feed a 175kc signal into the antenna terminal resulted in a barely audible sound from the radio. I checked the voltages, and figured out that all of the screens in the front end were missing voltages - which they get through a 25k resistor, which, I had connected to the wrong terminal after redoing a bakelite block. Ugh! After fixing that, it plays.
A couple things I noticed - it seems very sensitive and selective for an early radio. Tons of volume, but sound quality is only ok - I'm thinking due to the primitive speaker with a stiff spider. Also, voltages are all high - probably because of the replacement transformer. B+ at the rectifier is 310v, so I need to find a way to reduce that. I also noticed (how I missed this before, I have no idea), all tubes except for the 47 are 6.3v equivalents of the originals, obviously whoever worked on it had trouble finding a transformer with a 2.5v winding. I don't blame them for converting it over.
I tried to adjust the oscillator at 600kc, and found the adjustment didn't do much. I might just leave it, it works ok. I also really need to get grommets for the tuning capacitor, it's completely loose.




