09-04-2017, 02:48 PM
You guys are good. Injecting a 470 kc signal into the 6A8 oscillator grid was easy enough, and revealed that - yes indeed, the 470 kc signal comes up gradually followed by the sudden "popping in" of the radio signal.
And it is doing this on all five bands.
So...that means it must be something in common with all five bands.
Let's see...other than the 6A8 tube which has been replaced once already, there is capacitor (31) and resistors (32) and (33). I think cap (30) can be eliminated as a potential problem as it appears to only be used on the upper three bands.
That's my thoughts...unless all five oscillator coils are suffering from the same moisture absorption (possible, I suppose).
Regardless, unless youse guys have any other ideas, it looks like the RF unit is coming out again...ugh...
I hear you already. "Post the schematic!" This will get you started:
http://www.nostalgiaair.org/pagesbymodel...013222.pdf
And it is doing this on all five bands.
So...that means it must be something in common with all five bands.
Let's see...other than the 6A8 tube which has been replaced once already, there is capacitor (31) and resistors (32) and (33). I think cap (30) can be eliminated as a potential problem as it appears to only be used on the upper three bands.
That's my thoughts...unless all five oscillator coils are suffering from the same moisture absorption (possible, I suppose).
Regardless, unless youse guys have any other ideas, it looks like the RF unit is coming out again...ugh...
I hear you already. "Post the schematic!" This will get you started:
http://www.nostalgiaair.org/pagesbymodel...013222.pdf
--
Ron Ramirez
Ferdinand IN
