Fwd: [Elecraft] KPA100 Failing to Produce High Power

[Don Wilhelm]

Curt,

If you are transmitting full key-down for more than a few seconds (as 
with digital modes), you should limit the power to 35 watts.

The CAL TPA menu will provide a reference for when the fan turns on - be 
certain you have it set correctly - allow everything to cool to room 
temperature (at least 1 hour) and then set the CAL TPA parameter to 
correspond with the room temperature in degrees Celcius.

If you have not snugged down the mounting screws for the PA output 
transistors yet, please do that to assure that they have adequate 
contact with the heat sink.

Yes, the PA transistors will be hot to the touch after a few seconds of 
keydown - but SSB and CW are intermittent modes, and full power is 
normally only present for brief periods.  The KPA100 watt rating is only 
valid for CW and SSB modes, for other contiuous duty modes, 35 watts is 
the recommended maximum power.

73,
Don W3FPR

Curt Milton wrote:

> 
> i do notice the finals are too hot to touch when
> transmitting, but they cool in a few seconds when
> transmit ceases.  maybe this is normal (i have never
> touched an operational 50 watt device before).  i
> guess i need to find where the K2 will tell me its
> temperature to see if all is well.    
> 
> 73, curt