12-22-2013, 11:49 AM
I decided to add the negative feedback circuit similar to what Philco used in their late 1940 sets. That approach involves adding a 4.7ohm resistor and a 68 ohm resistor in series across the secondary of the audio output transformer. I did not have a 4.7 ohm resistor, but I did have over 100 10 ohm resistors, so I paralleled two of them to make a 5 ohm resistor. I soldered a 68 ohm resistor in series with the 5 ohm resistor across the secondary of the output transformer. I added a terminal strip alongside the transformer to hold these two resistors at their junction. Then I added a yellow wire back to the terminal strip where the black wire from the volume-tone control circuits came from the top of the chassis to a terminal strip underneath. At the same time, I removed the wire that was added that grounded that point. Now the negative feedback will be restored and keep distortion to a minimum as the designers intended.
Joe
Joe