[Elecraft] Silent power supply for a K3s

[Leroy Buller]

This is an issue that I have also, but have chosen to ignore.  I have the
samlex, astron ss30 and a rm30.   The Quiet one is the rm 30.  You might
try to tighten the bolts on the transformer.  That helped mine, but no fan.

One issue is keeping the power cord short to keep from getting a voltage
drop.  You also have to use the right gauge of wire and 45 amp power pole
connectors.   So, the power supply has to sit close to the rig.   I have a
cord of 24 inches.  I have very little voltage drop and the K3 runs better
at 13.7 than 11.8v.

So, I have learned to ignore the fans on ft8, and I wear headphones for the
other modes.

Your mileage may vary, but if it has a fan you will get noise.  The AL 82
also is noisy but that's life.

Lee K0WA

On Sun, Jun 9, 2019, 9:53 AM Peter Dougherty <lists at w2irt.net> wrote:

> Hi all,
> I would like to find a power supply to power the K3s that is completely
> silent. I've owned an Astron RS-35M, which was great until it started
> buzzing like crazy. I swapped that out for a Samlex SEC-1235M, and did the
> fan mod to keep the fan on constantly at low speed. The problem here is
> that
> when I'm running FT8 or RTTY for more than about a half hour, the fan goes
> into high speed and stays there for an hour or more, long after the rig and
> amp's fans have shut off. And because it's a tiny fan moving a lot of air,
> it's incredibly loud.
>
> I'm looking for an RF-clean power supply (either linear or switching) that
> can deliver 25A continuously without requiring a cooling fan of any kind.
> All it's running is the K3s/P3 and a couple of boxes with less than 1A draw
> each. The front panel meter on the Samlex is showing a tad over 20A when
> transmitting 100W in FT8/RTTY. Any suggestions? Within reason, cost isn't a
> major issue.
>
>
> ---------------------------------------------
> 73 and Good DX
> Peter, W2IRT
>
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