[Elecraft] KSB2 ALC question

[akern@haverford.edu]

Just installed the KSB2 module into K2 S/N 3547 and got it up and
running.  I notice that when on USB with the ALC enabled the S-meter
registers one or two LED's and the receive audio seems slightly
attenuated.  Switching to LSB or CW returns reception to normal insofar
as the ALC is concerned.  After experimentation (all the while with the
antenna disconnected) I discovered that, under any circumstances, turning 
off ALC solves the problem while in USB mode.  Interestingly, the ALC
triggers only when I have FL2 (OP1) or FL3 (1.8 kHz) enabled.  When I use 
FL1 (i.e. the SSB transmit filter) for receive the ALC behaves normally
regardless of its setting.  When I connect the antenna I can certainly
copy signals and make QSO's in USB using any of the filters, it's just
that the receive audio gets attenuated due to ALC response with FL2/3.
Any ideas?

Could this simply mean that I need to readjust the R1 carrier balance
control on the KSB2 board?  When I peaked it with an external receiver
during setup (per the instructions) I noticed that the minimum carrier
signal amplitude was much more pronounced on USB than LSB, and I think
that I tuned R1 to be closer to the carrier minimum experienced in USB
than in LSB.

Otherwise, the radio is playing FB.  Will keep building later this week.  
Thanks for the help!

-Adam, N1KO