SB-104A help with the carrier generator board ("E" board)

[Ron Manfredi]

Hello to the group.

I need some help troubleshooting the "E"  board (Carrier Generator) on
my SB -104A.  I don't have the extender board, so testing has been
interesting.  The CW filter is installed on the board, which is a
greenish material, with film resistors, which I think means it is one of
the later models. (?)

It appears that the USB oscillator is not working.  I can receive well
in LSB, but in USB or CW signals sound very weak, and garbled, as if
there is no BFO running.  WWV on 15 Mc does not have a heterodyne when
tuning across it in USB or CW.  From what I can test, the switching
diodes appear to be good;  passing voltage when the appropriate switch
is pushed in.   Voltages at Q612 and Q613 check out OK.  I did find that
I do not have any RF voltage on the collector of Q613 when in USB.