Transformer resistance tables for T3

T3 is the last in the 455 kc IF chain and feeds a rather substantial signal to the demodulator circuits. It seems to be a simple 1:1 transformer with each side consisting of a tunable capacitor/inductor pair.

Either they had a hard time getting it right or it doesn't make much difference what they use.

I noted that the wire colors were consistent across all the part numbers. I don't think this is the case with the other transformers.

Of the five radios I've examined:

1. Late radio. Had p/n 50B083. Variable caps plus fixed caps.
2. Late radio. Had p/n 50B083. It was sold before any of this work was started. Pictures indicate it was identical to #1.
3. Late radio. Had p/n 50C136. Fixed caps only. Variable coils.
4. Early radio. Had p/n 50-083. Variable caps only.
5. Early radio. Had p/n 50B132. Variable caps only.

Note that p/n 50-083 and 50B083 are not the same thing.

Radio #1

Has 80 pf fixed caps in addition to variable caps. Variable is 7-45 pf (or was manufactured in August 1945).

            Red - blue: 10.26 ohm
            Black - green: 8.75 ohm
        

Radio #3

Fixed caps and tuneable coils. Cap value not known at the moment.

            Red - blue: 6.83 ohm
            Black - green: 6.84 ohm
        

Radio #4

Variable caps only. Nothing printed on them. They're much thinner than the others.

            Black - blue: 6.51 ohm
            Red - green: 8.75 ohm
        

Radio #5

Variable caps only. Marked 70-90 mmf (pf)

            Black - blue: 6.45 ohm
            Red - green: 6.19 ohm
        

Page: /T3/Resis_tbl.shtml

Last modified: Friday, 24 Apr 2026