01-03-2021, 08:15 PM
Neither the lower sg voltage or the coil resistance would seem to be a fatal fault. Using a 6D6 for the 78 is a bad idea. Electrically they are similar in reality they don't work.
I would try applying a 460kc modulated signal to the grid of the 78 or the plate of the 6A7. This way there won't be any adverse effect from the generator loading the circuit and you can peak the IF trimmer(s) that are downstream. If you really think the 2nd if trans is bad you can use a 455kc can from the junk box to give it a try.
Happy New Year!
I would try applying a 460kc modulated signal to the grid of the 78 or the plate of the 6A7. This way there won't be any adverse effect from the generator loading the circuit and you can peak the IF trimmer(s) that are downstream. If you really think the 2nd if trans is bad you can use a 455kc can from the junk box to give it a try.
Happy New Year!
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry