Today's Mystery Guest (RCA CTC-4)

[Phil Nelson]

Originally Posted by Phil Nelson

Sure I can measure. The parts are supposed to arrive in a few days.

Here's the data sheet for the 4.5-MHz trap:



The sheet identifies that as a 47-mmf cap. Two of my traps have a 47-mmf cap and the third has a 45-mmf cap. They all measure 2.2 ohms across the coil:



I put one of them on a scope with a 4.5-MHz signal and was able to peak the amplitude by turning the adjuster. I don't know if that's where you want the adjustment to be in the preamp, but I was curious.



Haven't done much beyond that inspection, except to collect the needed parts. Perhaps I will create a new thread about building the preamp.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html