[Elecraft] KPA500 PA current

[Andy Durbin]

"On 20, however, even at lower power output levels, the PA current is high and the fan comes on and steps up quickly!"

As Bob has said, KPA500 PA current (also PA dissipation and PA efficiency) are strongly dependent of the load presented by the antenna system.   To understand what is going on you will need to know the complex load presented to the KPA500.  SWR is insufficient to characterize the load.   Avoid any load with R significantly less than 50 ohm even if the SWR looks ok.

Some of my test data is shown here - https://tinyurl.com/y37szlko

73,
Andy, k3wyc