12-18-2014, 08:05 PM
I'm working on a Delco 32 volt 4049 farm radio. I've successfully repaired the power supply (vibrator) and have slowly worked my through the chassis replacing all caps. The vibrator gets the voltage up to around 100 v in the chassis.
I actually got it to receive a station for a short period of time, sounded like it was underwater, then slowly came in and sounded OK before I lost it, and still have no reception again as of yet. The Audio output is OK, and all tubes are good, with all filaments up. It uses 2 78's, a 75, a 35, a 6B7 and a 43 output. The 78's and 6B7 are NOS. THe chassis was rusty, so cleaned it up, polished the sockets and shields. Any thoughts or suggestions would be helpful.
The issue I ran into is a broken wirewound resistor from fumbling fingers. It is very fragile, looks like a red cloth wire, but is actually fine wound wire like a long spring. I had to look this up to figure out what it was. I had no experience with it before. It is a 275 Ohm unit in the B+ from the RF 78 tube at 3 volts. If I did the calculation right, I get .14 watt, as its 2X3VX3V/125V
I can find so far a 270Ohm 1/4 watt.. Would this work correctly?
I am a newbie, and have so far done OK, my first fix being a 42-380. THanks for your patience!!
Mike
I actually got it to receive a station for a short period of time, sounded like it was underwater, then slowly came in and sounded OK before I lost it, and still have no reception again as of yet. The Audio output is OK, and all tubes are good, with all filaments up. It uses 2 78's, a 75, a 35, a 6B7 and a 43 output. The 78's and 6B7 are NOS. THe chassis was rusty, so cleaned it up, polished the sockets and shields. Any thoughts or suggestions would be helpful.
The issue I ran into is a broken wirewound resistor from fumbling fingers. It is very fragile, looks like a red cloth wire, but is actually fine wound wire like a long spring. I had to look this up to figure out what it was. I had no experience with it before. It is a 275 Ohm unit in the B+ from the RF 78 tube at 3 volts. If I did the calculation right, I get .14 watt, as its 2X3VX3V/125V
I can find so far a 270Ohm 1/4 watt.. Would this work correctly?
I am a newbie, and have so far done OK, my first fix being a 42-380. THanks for your patience!!
Mike
