[Elecraft] [K3] K3 fan noise, part XXLIV

[Tom W8JI]

> It seems pretty clear that the early fans were indeed 
> silent, certainly the
> same cannot be said of the UTEC ones in my #980.  Gary 
> kindly even sent me
> some more but the difference was negligible.  I have spent 
> a lot of time on
> this, even mounting the fan panel on rubber bushes - all 
> to no avail.

That isn't surprising. Fan mounts, although people really 
like to mess with them, almost never have a noticeable 
effect on noise.

Other than the design of the fan itself, the number one 
thing that affects noise is having an object near the blades 
(especially out near the tips). Restricting the airflow also 
doesn't help. The worse thing to do for a given amount of 
restriction is place it on the fan inlet.

I haven't played with a K3,  but cutting some thick spacers 
to move the fans outward from the PA might be worth a try. 
Cheap sound meters are readily available, and a good way to 
test.

73 Tom