[Elecraft] Power Readout Discrepency

[Parker Buckley]

Don and Ron, here's some better data.  I had made my
previous comparisons with the dummy load at the far end of
an internally bypassed Palstar antenna tuner, a coax switch,
a homebrew tuner-tuner, and the Diamond wattmeter.  Hard to
say what all that does to the poor K2 trying to push a few
watts through it.  With the dummy load right on the back of
a WM-2 wattmeter and a short piece of coax from the rig
straight to the wattmeter, shown below is the displayed
power on the K2 to get 10 watts on the WM-2.  I get very
different values now, and for the most part they are within
10%!  Sometimes I have to do this to myself.  Sorry to drag
everyone else through it.  :)

Here's the data from 160 to 10 meters for 10 watts on the
WM-2:

8.5, 9.4, 9.9, 9.9, 10.8, 10.8, 11.7, 12.2, 12.2

According to the WM-2, the Diamond wattmeter, the tuner
tuner, and the coax switch each provide an impedence bump
resulting in some reflected power.  Thankfully, the Palstar
tuner switching is not a problem.  I am about to eliminate a
few accesssories and/or rely on the WM-2 for power settings;
not the K2 display.  I think I've learned enough this time,
and will just go look for a QRP contact somewhere.  Thanks
for all your patience.

Parker WD8JOL