12-11-2023, 03:56 AM
So as if to taunt me, shortly after typing the above post, I had another volume drop issue. I checked the second RF and oscillator transformers - all windings are good including the pesky tickler coil. I had already reduced the 15k resistor in the oscillator circuit to 10k and replaced the 700 pf cap in the bakelite block with 750 pf (three 250 pf silver micas in parallel).
I did two things to try to resolve the issue (not the best approach to diagnose an issue, but I was getting a bit annoyed).
-Swapped in another 36 tube in case it was an oscillator issue (doesn't seem to be the case as I can still hear stations).
-I noticed the rivet for the antenna Fahnestock clip was a little loose. I warmed up the gun and soldered both sides of the rivet (above and below the chassis) to ensure a good connection.
In earlier stages of the restoration, the volume control was replaced with a correct tapped unit from Mark Oppat and the tone control and bandswitch were thoroughly cleaned.
Anything that I am missing?
I did two things to try to resolve the issue (not the best approach to diagnose an issue, but I was getting a bit annoyed).
-Swapped in another 36 tube in case it was an oscillator issue (doesn't seem to be the case as I can still hear stations).
-I noticed the rivet for the antenna Fahnestock clip was a little loose. I warmed up the gun and soldered both sides of the rivet (above and below the chassis) to ensure a good connection.
In earlier stages of the restoration, the volume control was replaced with a correct tapped unit from Mark Oppat and the tone control and bandswitch were thoroughly cleaned.
Anything that I am missing?
