[Elecraft] K2 Buyers remorse

[Mike Harris]

Hi Jerry,

Yes the little fan is a screamer. It's job is to remove heat from within 
the K2 chassis rather than cool the actual PS transistors.

Now to rake over old coals.

A few years ago I was providing a signal source, QRSS 30 seconds dot 
period for a mutual grey line propagation investigation between the 
Falklands and the UK/EU. The fan became a problem because I left the K2 
keying overnight at 20W and the shack is adjacent to the bedroom. The 
lady of the house was unimpressed. To overcome this I purchased a 80mm 
square 12V computer fan and experimented with location and orientation 
to determine the best solution.

This is where there is a divergence of opinion. I found that by propping 
up one side of the fan on a simple square wire loop so that it was 45 
degrees inclined to the heat sink and blowing down on it at the location 
of the PA's I could run the K2 at 30W output overnight and the fan never 
activated, the heat sink remained cool and was acceptably quiet. Shack 
ambient about +20C (68F).

At that time some hotly recommended that the correct way to orient the 
fan was to place it directly on the heat sink sucking air through the 
fins. I tried this but did not find this to be the most effective solution.

My logic, if you can call it that, is simply if I am faced with a hot 
object, say a spoon full of soup, if I want to cool it a little I blow 
gently on it, not try and suck air from all around it.

Whatever, I'm not going to die in a ditch over it.

I only used this arrangement for the rather extended duration of the 
tests. Normal DXing which at the time netted me 200+ DXCC before I built 
a K3 seldom activated the little screamer.

I can email you a picture of the setup if you wish.

Regards,

Mike VP8NO



On 07/08/2021 22:35, jerry wrote:
> All,
> 
>     Not sure if I'll actually be using this PA...  The fan is just so 
> LOUD!  It's like a mini turbine engine running on my desk.
> 
>                  - Jerry KF6VB