[Elecraft] K3 RF Output Level Variation

[Dave Barr]

K3-100 sn 7901 is working great;  I am still in the learning cycle, but 
I have noticed an interesting and slightly disturbing  thing about the 
rf output levels.

During measurement with an external (HP) power meter, the power output 
increases rapidly for about 10 seconds and then slows and eventually 
settles, with small variations from every few seconds afterwards.  For 
example, to achieve a 5 watt reading on the power meter, the initial 
setting on the K3 is 4.3, and within 10 seconds must be reduced to 3.9 
to maintain 5 watts output.  (Watt meter calibration has not yet been 
performed.) This occurs to similar extents at all power levels, i.e., to 
maintain an even power level, the K3 setting must be reduced over the 
first 10 seconds or so.   My K2 does much the same thing.  Is there an 
explanation for this behavior?

Dave, K2YG