Look for VR9 in the service manual to turn down the side tone output.

Its the only way that I can see to accomplish what you want.

Thanks for the info - right after I posted it, I found that myself as well.
That
indeed will do the trick - now to find pot VR9 on the IF board.... hopefully
it isn't too well hidden (why didn't they bring a Sidetone volume out to the
front or rear panel? I can't be the only one who doesn't like the sound of
the Kenwood sidetone!)

Dave WB7AWK