Hello everyone.

I have a President Mckinley export CB radio with the Uniden PC-893 board (identical to the Teaberry Stalker 9 Fdx) with AM-FM-SSB modes. It has the AN612 balanced modulator, and a transistor labeled TR27 (2SC2945AQ) for the unbalance switch.

I would like to make the direct injection modification to improve audio quality. I have a Behringer mixer with mic compressor, a Samson mic, and a passive box (impedance match).

I have read about this procedure in the forum for Cobra and other President radios. For what I have read, it seems that in most CB radios the balanced modulator is only used for SSB, and that for AM mode they use a transistor that series-modulates the final.

My question is, where should I drive the audio that comes from the mixer into the CB radio for the AM mode? And for the SSB mode?

Any help is appreciated, thanks in advance

Alessb