[time-nuts] Power supply help

[Joseph Gray]

> A good test would be to load it down to its rated current and voltage
> and monitor noise with a clamp on current probe ( on one lead)
> to a low frequency spectrum analyzer

I don't have a spectrum analyzer. I emailed a friend about using his.

> Open it up and look for tell tale signs of the original equipment
> manufacturer, possibly on the PCB.

I don't find any vendor markings on the boards that I can see. The
main switching circuit is housed inside a metal box that would be
difficult to take apart. The entire assembly is built into another
metal box that has a removable top. Everything seems well shielded.

I did do a test last night, using my Sony ICF-2010 shortwave receiver.
I can't power the Sony directly from the 13.8VDC, but I did plug its
power adapter into the same AC socket as the HP supply. With the Sony
sitting on top of the supply, I didn't notice any noise from the
supply on 80M-10M. I thought I heard some noise on 160M, but that band
was so noisy that it was hard to tell.

If my friend with the spectrum analyzer comes through, I'll be able to
see some real measurements on the DC output itself.