[Elecraft] [K3] Intermittent power loss

[Ignacy]

After a few QSOs in SSB my K3 starts dropping power. Sometimes this comes
with ERR TxG.  The power drops to 30-50W then to below 1 W. Sometimes PTT
stops working. Same on CW. After a few minute break, full power comes back.

I set DVR on a  continuous loop in SSB. The power started dropping to 50W in
about 30 min; PA temp was 38C. After stopping and restarting the transmit,
the power dropped below 1 W. After a few minute break, full power continued
for the next 20 min despite PA temp rising to 44C.

I tried to replicate the problem with a carrier or CW. No problem. Perhaps I
did not try hard enough but after 20 min and PA temp of 55C everything was
OK. 

I did the calibrations etc.  Also PLL seems to be fine. The problem occurs
on all bands.  Following an old message that the 2.7 filter may be wrong, I
cheated the system to transmit through 1.8 filter, with no change.

The problems start after about 5-30 min of transmit so the onset is random.
I can send the rig to Elecraft, but I am afraid that they may have a hard
time replicating this problem. 

One extra hunch. When the power in SSB drops, the SSB signal is distorted
like going through a  class B amplifier.

Ignacy



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