[Elecraft] K3 - Strange problem on 10 Meter SSB with power out

[williamsonr at pbtcomm.net]

If this has previously been discussed - please forgive me.
This weekend ten meters was "open" (as much as it could be at the bottom of a cycle) and the 10-10 contest gave me a great opportunity to try out the 10 meter band on my recently completed K3 #1318(latest firmware).  All seemed well until I noticed that my power output on SSB was down as indicated on the K3 power meter and where I normally see 100 watt pep output on my tuners average reading meter.  So I grabbed my Bird 43 (with PEP option) and a dummy load.  Sure enough, only about 50 watts PEP even though the control on the K3 is at 100?  Placed the K3 into tune and 95-100 watts out?  Go back to SSB and now the PEP power is back where it should be at approx 100 watts PEP.  After a few more SSB transmission - low power again(still connected to the Bird and dummy load).  This went on for a while as I checked and re-checked all of my mic and comp settings.  All other bands worked correctly.  Power supply not current limiting, all connections/cables good (connection to my statio!
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n ground verified), fresh battery in my studio mic, SWR on ten meter antenna below 1.4:1 etc. etc.  Took the LPA heat sink bottom cover off to make sure the LPA transistors were making good thermal contact.  (I had added a spot of heat sink compound to each transistor during my assy process) There was a clear outline of the TO-220 transistor and an even film of compound indicating good pressure and contact.  Put everything back together. Haven't seen the issue again - yet?  But I am not convinced I did anything to make it go away?

Anyone else had this experience?

Rodger
N4NRW