Today's Mystery Guest (RCA CTC-4)

[Phil Nelson]

Originally Posted by old_coot88

see if you can locate the mixer plate adjustment. It may be a slug or a trimmer.

The schematic shows trimmers and adjustable coils connected to pin3 of the 6X8 oscillator/mixer:



Some (maybe all) of those three trimmers may be accessible through holes in the tuner cage. I haven't found a diagram that shows all of that clearly. The Sams schematic does not show the adjustable coils (L42, L56)at all, and my photos of the tuner taken while cleaning don't show the internals clearly enough to guess whether they exist in my set.

Originally Posted by Username1

Take off the rca plug from the tuner into the if strip, parallel it to feed both sets

I was ready to run out and try this, when I remembered that the CTC-11 cable unplugs, but the CTC-4 cable is soldered on. I'm debating whether I want to unsolder it yet another time. It has already come off twice -- once for cleaning the tuner and again to lubricate the fine tuner when it got sticky.

Phil Nelson

[old_coot88]

Phil,
There is no mixer plate coil as there is in later tuners. Please scratch that whole idea. I should not have brought it up. Please don't mess with any of the trimmers or slugs, as they are strictly oscillator related.