[Elecraft] KX1 speaker output with superimposed oscillation

[wb2srf at juno.com]

Try changing the value of R21 from 2.7K to 4.7K 

I had a similar problem with load sensitive parasitic oscillation of the
LM386 with a Norcal 40
When this happens it can block the receive signal because of the agc
action.

The (high frequency rolloff) feedback may be causing enough phase shift
to cause the amplifier to oscillate.

Hope this helps

GL 73,
Bob Johansen WB2SRF