[Elecraft] KPA-500 fan noise

[Jim Brown]

On 6/3/2014 7:19 AM, Harry Yingst via Elecraft wrote:
> Replacing the fans was a worthwhile improvement and made copy easier.

Something does not compute. The fan in my KPA500 is pretty quiet on RX, 
and only gets loud during long transmissions, continuing for a short 
time (a few seconds) after that. How does a fan that is noisy only on TX 
make copy difficult on RX?

Another thing that doesn't compute is that a lot of the noise I'm 
hearing is air flow. Perhaps the replacement fan is running slower, 
which would reduce air flow, which would reduce cooling. Again, I would 
approach all of this with great caution. Cooling of power devices is as 
important an element of the design of amplifier as any of the rest of 
the circuitry.

I think it's a mistake to think that we hear the fan because it's a 
"cheap" or inferior one. We hear it because it's working.

73, Jim K9YC