[Elecraft] K2/100 Power Measurements

[Holger Doerschel]

Dear Don,


I read at the K2 13.6 V. It is a Powerwerx PS from Elecraft with the two 
Powerpole connectors at the front. The Voltage drops at 100 W / 28 MHz 
to 12.2 V. I already replaced D16. No change. I tried several PS.


73,

Holger DL9HDA


On 05.11.19 02:46, Don Wilhelm wrote:
> 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!
>