[Elecraft] Thermal control for Q1 / Q2 in KPA100?

[Don Wilhelm]

Tom,

Yes, we should all see what you have created.  How about a photo and a short
note on your website (no need for a .pdf file IMHO).  Such an addition is
great for those running digital modes and is nice to have when operating hot
and heavy during a contest.

As you have pointed out, it is important that the fan moves air upward so it
aids the flow from the internal fan rather than blowing air onto the heat
sink. Just laying a muffin fan on top of the heat sink is effective as a
'quick and dirty' solution, your plenum sounds like a great permanent
addition for those instances where there is not a lot of free-air space
above the K2/100.

The fact that an exhaust fan flow cools objects better than blowing air onto
a surface is a bit counter-intuitive because standing in the downstream side
of a fan feels cooler to the skin - but that is only because of evaporation.
Careful measurement will show that the cooling effectiveness for an object
like a heat sink is more effective by moving the heated air away from the
object.  Getting the heat away is the objective, and blowing on it is less
effective than exhausting the heated air.

73,
Don W3FPR

> -----Original Message-----
>
> I've made a cooling 'plenum' for my K2, using a very lo-profile cover
> and a tiny muffin fan from a CPU cooler. It pulls cool air in from
> outside across most of the heatsink fins and exhausts straight up. I
> can supply illustrations and some info on the design if you, or
> anyone else might be interested.
>
> Cheers,
>
> Tom   N0SS
>
>
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