New person here. I had a radio repair business in the 50's when I was in HS and worked my way through college as an electronics tech. All of this indicates that I should be able to solve this myself, but then I'm always ready to learn from others especially if it saves me time. 
I bought this 38-12 at a garage sale and it worked initially then one day I turned it on and there were no signals. I verified that the LO was working by listening for it with another radio. Then poking around with a scope I found the oscillation at the plate of the IF stage. This oscillation is at 470 KHz and is tuneable with the first IF transformer. Touching the grid cap of the IF amplifier stops the oscillation.
I verified the voltages at the tube sockets and they all were ok. I wiggled the tubes in case there was corrosion on the pins. All of the coils measure ok resistance wise and weren't shorted to somewhere they shouldn't be. I bridged all of the bypass caps with a cap of the same value and that didn't help. I intend to replace the caps but won't be able to get enough of the right values until next week.
I googled this a bit and didn't come up with anything.
Is this a common problem with a known fix?
Any suggestions will be appreciated.
I bought this 38-12 at a garage sale and it worked initially then one day I turned it on and there were no signals. I verified that the LO was working by listening for it with another radio. Then poking around with a scope I found the oscillation at the plate of the IF stage. This oscillation is at 470 KHz and is tuneable with the first IF transformer. Touching the grid cap of the IF amplifier stops the oscillation.
I verified the voltages at the tube sockets and they all were ok. I wiggled the tubes in case there was corrosion on the pins. All of the coils measure ok resistance wise and weren't shorted to somewhere they shouldn't be. I bridged all of the bypass caps with a cap of the same value and that didn't help. I intend to replace the caps but won't be able to get enough of the right values until next week.
I googled this a bit and didn't come up with anything.
Is this a common problem with a known fix?
Any suggestions will be appreciated.
