05-03-2013, 10:20 PM
When you had the radio powered up, did you do any voltage checks on the RF, osc/det or IF tubes? If you have plate voltage ( around 200V-250V) on the plate socket pin of each of these tubes, then you can assume that the primary windings of their respective coils are ok. The plate voltage is fed through the coil, so if it is open there will be no plate voltage on that tube.
Typically the coil resistances will be on the order of a few ohms up to 50 or so for an IF transformer coil. Anything much higher than that would be suspect.
The det/osc circuit is a bit complicated because a single tube is used as both a mixer and oscillator, called an Autodyne circuit. The plate circuit contains both an oscillator coil and an IF coil. If either has an open winding you will get no reception at all. This is where I would first look.
http://www.nostalgiaair.org/PagesByModel...013837.pdf
Typically the coil resistances will be on the order of a few ohms up to 50 or so for an IF transformer coil. Anything much higher than that would be suspect.
The det/osc circuit is a bit complicated because a single tube is used as both a mixer and oscillator, called an Autodyne circuit. The plate circuit contains both an oscillator coil and an IF coil. If either has an open winding you will get no reception at all. This is where I would first look.
http://www.nostalgiaair.org/PagesByModel...013837.pdf
