[Premium-Rx] spikes & UPS's

[Blair Batty]

At 07:40 PM 6/5/2006, you wrote:
>G'day from Cairns,
>Interesting to read the problems with inrush, surges and spikes
>The problems of sag and surge are both best solved by a true online UPS, one
>which rectifies, stores and regenerates a new sine wave for the equipment.

I bought a top-of-the-line Liebert UPS that is fully on-line, regenerating
a new "pure" sine wave to protect my gear. Unfortunately, the internal
UPS power supply and the inverter both (I can hear them switch in
separately on different frequencies) generate so much broadband rfi on HF
as to make my Harris 590 unusable, (especially around 160 meters).

The noise is coming in the antenna; if I shunt the antenna with 50 ohm
plug the noise disappears. To listen to HF I have to switch the
UPS to "Bypass". I wanted the UPS to keep on-air during power
failures, so it isn't so useful. Any suggestions for fixes?

Sincerely,
Blair

P.S. Just because the noise is coming in the antenna, does not
preclude the probability that the AC power lines are acting as
the UPS's antenna...


Law of Logical Argument:
Anything is possible if you don't know what you're talking about.