[sdiy] Buchla switching supplies

[mcb, inc.]

On Tue, 21 Feb 2006, John Loffink wrote:

> Switchers
> are notorious noise generators at the switching frequency, typically
> anywhere from 50 KHz to 2 MHz, and extending (through harmonics) up to 100
> MHz or higher.

Somewhat related....  bored one day, I put a Tek scope on the
unloaded output of an old Soundblaster card to look at signals.
Noticing a bit of fuzz, I went up-frequency where I found a
very well-defined 100mV, 100MHz sine coming out of the signal
jack.  Given the frequency, this was likely cpu or pci harmonics.
Never followed up the investigation to see what happens under
load, etc., or if the test rig (*cough*) had a problem.  I'd hope 
something like a Hammerfall wouldn't do that.

m

--
Monty Brandenberg