[Elecraft] K3 has internal noise with high compression settings

[goldtr8 at charter.net]

Gents,

Last night I disconnected all the antennas and started to look at basics 
within the shack because of my antenna problem, I decided that I should 
check the basics with my dummy load and found an interesting thing 
happening inside my K3.

What I found is that when directly connected to a dummy load and I run 
the k3 at full power 110 watts, as I dial up the compression above 35 on 
the settings , I hear a hum inside the K3 and it shows RF out power in 
SSB when I am not speaking into the microphone.  Basically key up the 
mike in a quite environment in SSB mode and it goes into TX where there 
is output.

I made a coax choke with snap on ferrites between the dummy load and the 
K3 to see if I could kill it but it made no difference.  Also power 
settings below 110 did make some difference and mike gain had little to 
no effect.  This happens on all frequencies, does not matter if on 160m 
or 10m.

I then connected the amp between the K3 and dummy load and this noise 
starts at about a compression setting of 30 to 33.  This is with a drive 
power of 40 watts into an SGC powercube, and when the humming started 
there was TX power on my meter.

The internal noise sounds like a ferrite vibrating.

Other items, power is supplied via 12v batteries using a floated battery 
charger, existing antennas were disconnected from the system.

Is this something that others have seen or should I call Elecraft 
support.  I am hoping I don't also have a K3 problem.

Thanks
Don


~73
Don
KD8NNU