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RCI-2990 problems with balanced modulator/10.695 circuit?

Posted: Thursday 20th Sep 2018, 10:13
by timrim
I have an RCI-2990 that I am trying to repair. I have a complete test bench with everything.

The radio has a very high dead key on USB and LSB.
The AM works, except the frequency is unstable, like it it out of lock. Also, when I vary the power on AM, the transmit frequency changes.
If I remove D-45, the AM frequency is good, and the AM works perfectly, but the SSB is still off frequency and with a very high dead key.

I have replaced the balanced modulator and the variable for the balanced modulator and it still is acting up.
When D-45 is in circuit, the 10.696 does not show up on frequency counter like it is supposed to when connected to D-45.

I have been going in circles trying to pinpoint the problem.
Please give me some ideas as to where to look.