Today's Mystery Guest (RCA CTC-4)

[Phil Nelson]

Sorry, I've been flipping back & forth between the Sams & RCA schematics and jumbled some numbers.

The 10.8 ohms reading was across L127, the reactance coil. That is with everything connected on that coil.

Resistance from pin 3 to ground is 2.1 ohms. That's across L42 with everything connected. The RCA manual has no resistance chart, but for what it's worth, Sams says resistance at pin 3 should be .4 ohms, where I now measure 2.1 ohms.

I did some checking of T115, the CW transformer. Resistance across the primary (from B to E) is 7.0 ohms. Resistance from F to A (F to ground) is .1 ohms. Resistance from D to C (D to ground) is .1 ohms. This is with everything connected to T115.

Someone has worked in this area before. C202, the 120-pf cap on pin 6, looked like a replacement, attached hook-and-loop style to a stub left on the terminal. R246, 22K, is another obvious hook-and-loop replacement. The crystal may also have been replaced; one of its leads was much too long, and with strange bends -- not neatly dressed as you'd expect from the factory.

Phil Nelson