[Elecraft] OT: Astron RS-35M Transformer Hum

[Keith N6JPA]

You should purchase an Astron Switching power supply. They are well

made and filtered properly. I use a SS-25M that has a fan that runs at 
times,

but it is not too loud.

On 4/24/2020 9:48 AM, inventor61 . wrote:
> I have a CAD design for a replacement wooden top for the RS-35, -35M, and
> VS-35M Astron supplies.  This top cover looks exactly like the factory
> steel cover, uses the same mounting holes, and even has an exact duplicate
> of the vent slots.
> The material that worked out best was a HDF board.  It can be painted
> easily in any color including the factory textured black.
> The design is intended to be produced on a CNC machine like a full size
> ShopBot, as were the several prototypes, which really turned out splendidly.
> It of course solved the problem of the eddy currents in the steel lid,
> which for this size Astron is too close to the field of the power
> transformer.  These currents cause the acoustic noise.
> I was planning on bringing this replacement top cover to the ham operator
> market last year but I ran into production challenges.  It's simply too
> costly to produce these, ship them, and sell at an acceptable cost even
> ignoring making a worthwhile margin.
>
> If someone has a better idea than mine for making these, I am all ears.
>
> Steve KZ1X
>