The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench I have better noise.

I found a bad resistor it is #41 on the Olds schematic It is screen of the RF amp, osc and IF tubes. It is suppose to be 15 meg and was reading less than 3 k. Anyway I now at least can tune in a station. It is very weak but the 6sk7 RF amp tested weak. I may swap it with the IF amp just for kicks. The volume is also still very low. So now I wait a tube.

That is very good news. So, is your B+ a little closer to normal?

Boy Neil, that's really very unusual for a carbon comp resistor to go low, I've never seen that. All of the carbon comp resistors will eventually increase in value due to natural aging.

Although it is not often that I find a bad tube, all those tubes are available NOS at a very reasonable rate from many of the tube vendors like Radio Daze, Antique Electronics Supply, Tube World, Vacuum Tube Valley, Tube Store, Playthings of the Past, if your really in doubt about the tubes why not just re-tube the entire radio then you will have eliminated that as a problem probably for as long as you own the radio.
Denny G

My B+ jumped up to normal and we have radio. I went through and changed out all of the resistors that I could reach with out cussin this morning. These things sound great. Not great reception yet but it sounds pretty good on the local stations.

Denny you are correct I am not sure how a resistor would even go low. There is a good possibility that with my eyesight it was 3 something. It had to be high because my screen voltage was low. I was checking with a radio shack pocket digital meter with little bitty symbols. All of the tubes tested not great but OK except the RF amp that should help with the reception. The tester is an Accurate Instruments model 157. It is a small portable unit. Pretty much good, bad, shorted. The guy I got the tester from is pulling me a set of tubes.

I now have a new set of all but the 6V6GT's. It helped with the reception some on the low end of the dial. The upper end is all but dead. That is with the antenna trimmer wound out fully clockwise. I guess it may be time to find a signal generator. I think my cousins IFR service monitor will do the trick. Unless you guys have some other suggestions. It has been a long time since I have re-tuned a radio. 1973 would be about the last time.

Neilroy,
I don't have the Olds schematic in front of me but I think there may be a trimmer that affects the RF stage response. That may give you some shift in the characteristics.

http://www.nostalgiaair.org/PagesByModel/495/M0022495.pdf I am going to pick up the IFR service monitor Monday. If I remember right it will almost generate a signal from dirt to white light.
I just pulled up the Chevy schematic there are some subtle differences but the same basic stuff. The Chevy manual is much more detailed and has a lot more trouble shooting information. It pretty much looks like electronics for mechanics step by step. It even has pictures of where to hook up the signal generator. This should make things easier. The section on installation is great. I should have printed it off long ago.