[Joeztech]

The original Philco audio output transformer in this set was replaced with a Stancor A-3823. This transformer has a center tapped primary and two plate leads for the output tubes. With leads disconnected from the tube sockets and the spike suppression capacitors, I measure from CT to one plate lead 240 ohms. From CT to the other plate lead I measure 450 ohms. That is hardly balanced and it appears that this transformer has problems. Also on the secondary only two connections out of 6 possible taps are used. There are secondary taps labeled from 1 to 6 and the no. 2 tap is grounded to the chassis. The no. 5 tap is connected to the lead going to the speaker voice coil. According to the schematic provided by Philco, there is supposed to be a third secondary tap that connects back to the volume control low end and the center contact of the tone control. This is apparently part of a feedback circuit. In this set this lead to the tone control and the volume control was simply grounded when the transformer was replaced, so whatever feedback that Philco intended has been defeated.

Has anyone out there seen this happen on another 40-195, 40-200 or 40-201?

I have no information on the Stancor transformer to get any idea how the secondary should really be connected, but I suspect that tap no. 1 should have been grounded and tap 2 should have gone to the feedback through the volume and tone controls.

It appears I will need to obtain a new replacement transformer since the two primary circuits are not balanced. One side must have some shorted turns.

Is there a recommended replacement for the output transformer that is currently available? If not, then I will have to do more research before ordering a replacement.

Joe