[Elecraft] KPA1500 not amplifying

[Eric Swartz - WA6HHQ, Elecraft]

Hi Bob - Have you run the K3 TX gain calibration on each band into a dummy load 
(or very low SWR Ant.) ?   If that is out of cal, it could easily create 
symptoms like this.

73,
Eric
/elecraft.com/

On 10/22/2018 2:02 PM, n7wy via Elecraft wrote:
> Turns out, it is not the KPA1500 not amplifying, but rather the KPA3A final amplifier stage in my K3S is acting like it has tubes, not FETs.  It has to warm up at 30 watts out, and then the power can  be reduced to 20 watts.  Weirdly, changing the power level above 20 watts seems to reset tbe behavior so it has to be warmed again.  The KPA3A module that is present is the 2nd replacement/exchange.  The first 2 had high 2 tone IMD issues on SSB.
> My trustworthy K3 is now driving tbe KPA1500 without issues.
> Thanks for all the off reflector counsel and 73,
> Bob R  n7wy
>