[Elecraft] K2/100 "muting" by itself?

[kc4kgu@ENTERZONE.NET]

While using my K2/100 last evening, I noticed several times that it would
slowly "mute" RX audio.  The volume would decrease, almost like selective
fade but, that wasn't the case as my TS-2000 did not show this behavior
(switched the antenna over to the TS-2000, audio was there, back to the
K2, no audio) and the K2 hears better than it does to begin with.

During the course of a ragchew session, it would go from normal, down to
nothing (muted) and then pop back to normal again.  I also noticed that a
few times, when I unkeyed the mic, the radio would stop TX but, no RX
audio (no band noise, nada, zilch) would be there for a second or two and
then it would suddenly show up.

I have also noticed that in "test" mode for CW, the sidetone volume will
intermittantly decrease/increase.  It may do this when actually TX CW but,
since I don't operate CW much, I'm not sure.

Has anyone else seen this behavior before or know what I should look
for?  This is the first "real" use that my K2 has seen since arriving back
from Gary.

Note:  I was operating on 160m and _everyone_ I talked to was amazed at
the TX audio of the K2.  I use the "stock" MH2 microphone.  A couple of
people I talked to expressed that they had previously been intrigued by
the ads but, were seriously interested in building one after having talked
with someone using the product.

73 de John - KC4KGU
K2/100 #2490