[Elecraft] Power Output Regulation Issue

[Francis Belliveau]

All,

I have been trying to get a handle on how well my K2 controls output power 
for a long time.  I have finally acquired an LP-200 Wattmeter/Dummy load 
combination in order to provide a reasonable measure of this characteristic. 
The results are below:

For a setting of 5 watts
MHz   PWR
 3.50  4.76
 4.00  12.5
 7.00  5.01
 7.30  2.34
10.10  7.07
10.15  7.03
14.00  4.31
14.35  1.95
18.068  6.06
18.168  6.24
21.00  6.41
21.45  5.5
24.89  6.59
24.99  6.47
28.00  9.45
28.75  6.22

For a setting of 10 watts
MHz   PWR
 3.50  4.47
 4.00  12.1
 7.00  16.1
 7.30  8.74
10.10  13.2
10.15  13.1
14.00  17.6
14.35  12.0
18.068  11.7
18.168  12.0
21.00  12.8
21.45  11.9
24.89  11.9
24.99  11.7
28.00  11.1
28.75  10.6

Of greatest concern to my are the main bands 10, 15, 20, 40 and 80 meters. 
Where the readings look reasonable at one end of the band, they are way off 
at the other end.  I am wondering what might be causing such problems with 
power regulation?

The rig only had the SSB, NB and Analog Audio filter options installed when 
these measurements were made.

I very much need some advice on where to start looking and troubleshooting 
this problem.

Thanks,
Fran