[Elecraft] K3/P3 communication

[Bill Schwantes]

About 30 days ago I noticed that the K3 randomly keyed up and briefly
transmitted full power CW every few seconds while listening. This happened
with no action from me. I unplugged the paddle, mic, and headphones.  None
of these had any effect on this behavior. Tuning the K3 made this
uncommanded keying speed up and occur at a rate porportional to the tuning
rate.  This problem occurred abruptly.  The station had been working fine
for months before this occurred.

This behaviour stopped when I powered down the P3.

In the days following I went through the K3 menus, certain that I had
unintentionally selected something that cause this behaviour.  I found that
my transmit power setting for transverters was set below 1 miliwatt;
sometimes as low as  0.1 milliwatt. When I restored the XV drive power
setting to zero dB the uncommanded keying stopped, even with the P3 powered
up. Hmmmmm........

Now there's a different problem:  The P3 does not  initially display the K3
frequency upon K3/P3 power up.  Instead it shows the "#" symbol in the top
center of the screen. When this happens the P3 does not display the green
or purple frequency bands of the "a" and "b" VFO on the scope.  The
spectral display seems to be unaffected.  This condition can sometimes be
"fixed" by changing bands, especially when changing to a band that requires
an XV transverter to be powered up, but not always.  Band change
communication with the KPA500 occurs normally with or without the P3
powered up. Usually this P3 display behavior goes away and the P3 behaves
normally after 30 minutes of operation.  I seldom see it after an hour of
operation.

The station is all single point grounded.  Both the K3 and KPA500  are tied
to this single point ground.  P3 and transverters are not seperately
grounded.

The K3 has firmware revision 4.42. The P3 has firmware revision 1.09.

Apparently there is some marginal communication issue between K3 and P3.
has anyone observed this odd behaviour?

73, Bill
W7QQ