[Elecraft] K2: Power calibration?

[Randy Moore]

Today I was trying to check power output on a newly constructed SW-40+ 
(my second one) and needed to recalibrate my WM-2 wattmeter.  After 
doing that, I decided to check it against my K2 (#337).  Not even 
close!  The WM-2 shows 2.7 watts when the K2 shows 5.  It shows about 7 
w. when the K2 is set for 10 w.  I double checked the calibration on the 
WM-2 and put in a new 9v. battery and got the same results.  The WM-2 is 
supposed to read within 5% according to OHR.

I seem to remember lots of discussion about power calibration on the K2 
long ago and that there's a 1% resistor in there somewhere that's 
involved.  I wouldn't worry about it if I was within 10% or so, but I'm 
not even close.  I don't have another independent way of checking this.  
Should I believe the WM-2 or the K2 or neither???

73,
Randy, KS4L