[Radioroslyn]

Was looking over the diagram for my 116X and noticed that it uses a hum balance pot to null the 60cy AC on the directly heated output tubes (6A3's). This is a common practice with audio tubes that don't have a cathode. But wait. One of the 6A3's is tied across the pot and the driver tube heater and the RF tubes. The other 6A3 filament is tied across the IF amps,det,and 1st audio. It's filament winding has a ct which is grounded. Pretty Odd!!

http://www.nostalgiaair.org/PagesByModel...013123.pdf
Terry