[Elecraft] K2 KPA100 fan replacement?

[Don Wilhelm]

John,

That is not normal.  You might want to check a couple things.
First, connect an external wattmeter and monitor the actual output - set 
the power control at 50 watts and see how much power you actually have 
on CW keydown.
If it is much higher (greater than 100 watts), you have a problem with 
the KPA100 wattmeter.
Continued operation with that condition present will cause your base K2 
PA transistors to be stressed and will fail sometime soon.  Even if you 
operate with the power knob set below 11 watts, the base K2 PA will 
still be stressed because the base PA is putting out the maximum power 
that it can develop - often exceeding 18 watts.

Secondly, check the menu setting for CAL TPA - turn power off and wait 
at least 1/2 hour to allow things to cool to ambient.  Then power on and 
check the setting of CAL TPA - adjust to the ambient temperature in degC 
if necessary.

If you are doing CW (or data modes) with a high transmit to receive 
ratio, such as during a hot and heavy contest, you can set the fan to 
LO-HI so it will run at low speed all the time and keep things cooler - 
that means the times it switches to high speed will be reduced.

In normal mode, the fan does not run until the CAL TPA temperature (and 
the heatsink if CAL TPA is properly calibrated) reaches 40 degC and will 
turn off when the temperature drops to 36 degC.

73,
Don W3FPR

On 8/23/2014 7:31 AM, John Farmer wrote:
> it's more noticeable if you have well preserved high frequency auditory
> acuity :).  I use my K2/100 for QRP only, because if I work CW at 20W or
> more, the fan runs pretty much continuously on Tx.
>
>   
>