[Elecraft] SWR and Power readings RE: K2

[Charles Greene]

Hi,

I have a question concerning antenna power and SWR.  I am setting my K2 
power at 5 watts via CAT.  The K2 display reads 4.3 F, 0.0r.  An external 
watt/SWR dual meter reads 5.9  +/- 0.2 Fwd and a small value which can't be 
read accurately, Rev.  A Tandem SWR/Power meter reads 7.2 +/-  0.2 watts 
and a SWR of 1.2 +/- 0.1.

The question is, if the SWR is not 1:1, does the power reading which is 
based on the voltage in a 50 ohms load read high or low?   I don't think 
any of my meters have  SWR compensation in the power level reading, if 
there is any.  The Tandem has compensation for diode nonlinearity in low 
power readings.

I had measured the following on the antenna a few days ago using a AIM430 
antenna analyzer: http://w5big.home.comcast.net/sitemap.htm  SWR 1.1:1 +/- 
0.1, Zmag 48.5 +/- 0.5 ohms, Theta +5 +/- 2 degrees, Xs, a small + value, 
can't read it accurately.  I am using the KAT2 so what the K2 display reads 
on r is probably correct or it is less than 0.1 which is the LSD.

Also, if the power level is set by the K2 CAT at 5.0 watts, why is the K2 
display reading 4.3 watts?  If I have a very accurate wattmeter, can I 
calibrate the K2 wattmeter?  How about calibrating the CAT setting?  I 
probably can get a more accurate reading on the Tandem by using a DVM set 
on current in series with its meter(s).

73,  Chas,  W1CG