[Elecraft] KPA-500 Running hot on 20m

[Clay Autery]

Optionally, one can replace the internal fans altogether (the heat sink
is not sufficient for passive cooling under all conditions obviously).

If your installation is static, or relatively static, you can duct
cooling air from some place where the noise is "OK" to a properly
located input.
OR, you can put the duct on the outlet and put a suction device
somewhere remote where the noise won't be troubling.

Or, you could replace the heatsink altogether in favor of a water
cooling heat exchanger...

Or, other many varied solutions depending on your requirements and
acceptable trade-offs.

Thermal design is a hobby unto itself...  so many options...  I find it
a lot of fun.

73.

______________________
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

On 1/10/2017 11:21 AM, Ron D'Eau Claire wrote:
> With an adequate sized heat sink, one could build a legal-limit solid state
> amplifier with no fan whatsoever, but the most Hams want physically smaller
> equipment even if it requires cooling fans. It's not bad engineering. It is
> good engineering coming up with a product the buyer wants. 
>
> I know that Wayne went to some effort to make select K3/ K3S fans that are
> as quiet as possible while still providing the needed airflow for high
> duty-cycle modes. 
>
> The KPA500 demands far more air than the K3/K3S. 
>
> The only really silent fan is no fan at all. That's something most QRP
> operators enjoy. 
>
> 73, Ron AC7AC