[Elecraft] Low outout power on higher bands, K2

[Beth Wenzel]

Hi guys,

Been working on this problem for some time now,with no luck. 30 meters and below, I get 12-13+ watts out. 20m about 12, then a rapid drop off until I get about 1.5 watts on 10 meters.

I have checked all of the relays for proper switching in the bandpass and low pass filters, Have replaced the finals. Have rewound all of the transformers in the PA, and have cross checked all of the components in the RF chain.

10 meters peaks ok at 1.5 watts, but the ALC is in full drive to get 1.5 out.
The gain ratios in the PA look ok relative to the lower frequencies, however the bandpass filters on 15 through 10 seem to exhibit a higher insertion loss than the lower frequencies, (using a sig generator and an o-scope to check) in fact if I jumper the filters out, the PA puts out full power in 15m but only 5 watts on ten (I'm guessing there is an impedance mismatch problem). 

Any ideas? this is getting to be very frustrating.


73 Mark AB9LZ.