[BC] Can't Get A Direct Answer

[Rik van Riel]

On Wed, 24 Oct 2007 10:47:06 -0400
Tom Dimeo <mwam at 73kn.net> wrote:

> I've purchased two UPSs, a Tripplite and an APC and both of 
> them cause interference to the AM broadcast and shortwave 
> bands.  I've written to APC, Belkin and Tripplite trying to 
> find out if they have a UPS that does not cause this kind of 
> interference 

I have an APC Back-UPS 1000 here at home, which does
not seem to cause much trouble.

According to a discussion on freenode #hamradio, the
Back-UPS series are offline UPSes that mostly keep the
battery out of the loop, while the APC Smart-UPS are
online UPSes that cause RFI problems.

OTOH, I am seeing some RFI on eg. 10780 kHz and have
not tracked down the cause yet.  The interference is
strongest right in front of my monitors (when searching
with a portable radio), but completely unplugging the
monitors has no influence on the strength of the
interference on my R75 (which has an antenna in the
attic).

Unplugging the UPS has no influence on the interference
either.  It may be coming from somewhere else in the
house, conducted here.

-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan