08-22-2015, 07:45 PM
I went ahead with the signal generator and no dim bulb, and the results were encouraging. I was able to produce tone through the oscillator and finally through the antenna. Nice and clear with plenty of volume. Still no signal and noticeable hum, so I put a ground on the set and about 25' of antenna wire and got clear signal on both SW and Broadcast. The hum is still there which I guess explains why the guy in the 50s placed an 8uf e-cap between the chassis and the output.
Voltages with the line running at 115vac are still a bit off: the voltage at the CT is -17vdc and the voltage at the output plate is 270vdc. They should be -25vdc and 285vdc. Could having a 300ohm resistor instead of 270 ohm at the CT affect that voltage?
Correct me if I'm wrong, but the hum shouldn't be there. The reason it's hard to tell is that I have bad electrical interference at my house. Just about all of my radios have bad hum between 1100 and 1600. I'll try again later after the washing machine is done and the televisions are turned off, but I might call this one sort of fixed?
I have to do something more permanent for the antenna and ground. As of now, they are two wires with the black one soldered to the chassis and the white one soldered to a lug on the band switch. I think they had a terminal on the fiberboard back the radio used to have, but I've never seen a picture, so I don't know.
Voltages with the line running at 115vac are still a bit off: the voltage at the CT is -17vdc and the voltage at the output plate is 270vdc. They should be -25vdc and 285vdc. Could having a 300ohm resistor instead of 270 ohm at the CT affect that voltage?
Correct me if I'm wrong, but the hum shouldn't be there. The reason it's hard to tell is that I have bad electrical interference at my house. Just about all of my radios have bad hum between 1100 and 1600. I'll try again later after the washing machine is done and the televisions are turned off, but I might call this one sort of fixed?
I have to do something more permanent for the antenna and ground. As of now, they are two wires with the black one soldered to the chassis and the white one soldered to a lug on the band switch. I think they had a terminal on the fiberboard back the radio used to have, but I've never seen a picture, so I don't know.
Charlie in San Antonio
