[Elecraft] K2/100 Power Measurements

[Don Wilhelm]

Holger,

Is your power supply voltage at 13.8 volts or better yet 14.3 volts? 
That should be as measured by the voltage display on the K2.  It should 
not drop below 12.7 volts during a 100 watt transmit.

Part of the problem may be attributed to the voltage vs. frequency curve 
of KPA100 D16 - which should be a 1N5711 diode.  I have seen diodes that 
have become "flaky" with use, replacement with a new one is the only 
cure should that be the problem.

Other than limited voltage to the KPA100 or the response curve for D16, 
there is usually no other answer for the behavior you are seeing.

Remember that the power may vary by as much as 1 dB from band to band, 
and at the 100 watt level is about 20 watts, so you may not have any 
problem other than diode tolerance vs. frequency.

73,
Don W3FPR

On 11/4/2019 4:53 PM, Holger Doerschel wrote:
> Hi,
> 
> after I finally installed the KAF2 module in my K2/100 05775, it was 
> time to do a complete alignment and I ran into this old problem again.
> 
> The output power at 160 m is 100 W. And drops from band to band to 80 W.
> 
> Now I have adjusted the KPA100 to 10m. Now I have there 100 W but then 
> on 160 m 120 W.
> 
> Measured with an LP-100A and dummy load. SWR is fine!