Generic PS Spectrum

KiwiSDR waterfall with generic SMPS

Generic PS

Generic SMPS

I’m a bit startled at how difficult it is to find old-fashioned, linear power supplies these days. While I have acquired a couple of 5 volt, 3 amp units specifically for use with the KiwiSDR, I still have some work to do to get the needed wiring and plumbing done.

In the meantime, while pawing through my junk box, I came across a switch mode power supply (SMPS) that I recall was the one that came from Seeed Studio with my KiwiSDR.

As an experiment, I swapped out the generic SMPS I’d been using with the KiwiSDR for the original SMPS provided with it.

Generic Power Supply Spectrum

KiwiSDR waterfall with Generic SMPS

Kiwi Power Supply Spectrum


KiwiSDR waterfall with Kiwi-provided SMPS

I was kind of startled at the difference: The original SMPS is much better below 10 MHz, and especially in the area between MW and 7 MHz, but it is a lot worse in the 15 - 30 MHz range.

I’m anxious to get the linear 5 volt supply hooked up to see what kind of difference it will make. As per the advice at the KiwiSDR site, getting a quiet power supply seems to be a key factor in reducing “self-noise”.