[Elecraft] KPA500 clicks and thermal design

[john at kk9a.com]

I don't think the clicks have anything to do with the transformer mounting.
On my amp it occurs when the transistors heat up. Keeping the fan on a
higher speed will eliminate this clicking however then you have to listen to
fan noise. Perhaps Elecraft has a fix for this but I have not used the amp
enough to pursue it.

John KK9A


Craig Buck k4ia wrote:

Make sure the transformer is on straight and secured.  Mine clicked for a
while but has since stopped.

On Sat, Apr 21, 2018, 1:35 PM ANDY DURBIN <a.durbin at msn.com> wrote:

> I find the "clicks" my KPA500 makes as its temperature changes to be quite
> distracting.  Part of the problem is that I'm chasing a problem where the
> KPA500 changes band spuriously and the thermal clicks sound too much like
> the relays re-configuring the LPF.
>
>
> To what extend does the thermal design require conduction between the PA
> heat sink and the case metalwork?  Would the thermal management be
> compromised if very thin mylar strips were placed between the heat sink
and
> the case side panel , case rear panel, or Z bracket?
>
>
> Any other proven techniques for eliminating the thermal
> expansion/contraction clicks?  (I know the manual says this is normal so
no
> need to tell me that).
>
>
> 73,
>
> Andy k3wyc