[Elecraft] Seeking Help Solving KAF2 Problem

[Dennis Payton]

> Are you certain your KAF2 is tuned to your sidetone pitch?  If it is not 
> it
> will severely attenuate your signal.

The trimmers are peaked to the sidetone, but the audio is also just as 
attenuated in the "off" selection.

> I would suggest that you check the components on the KAF2 board for 
> correct
> values and good soldering.  Especially check R9, R10, and C16 because 
> these
> operate a phase shifter to restore the balanced output (the filter 
> sections
> themselves are single ended).

R9, R10, & C16 all tested good, but I ended up removing C16 to test it 
accurately. Then I was afraid the stress may have damaged it so replaced it 
with another 470pf NPO.

VAC measurements between the pins with the filter in were .077 at J1, .005 
at J2, and .000 at the LM380. With the filter switched out it measured .061 
at J1/J2, and .008 at the LM380. I guess that says the problem is in the 
filter?

Thanks for the advice, Don!

Denny    N9JXY.