HH
A small thought!
If your premises are powered by 115VAC (nominal)....
You can make an approx 40dB resistive L pad (1/100) to view /analyse
wideband /watchdog at 1.15V rms.
Use 1 x 470k series + 1 x 5k1 shunt (2% metal oxide).
This eliminates any HP filtering introduced by step-down transformers on
load.
Insulate its input wiring well.

"Dale Farmer" wrote in message
...


Harry Houdini wrote:

Jim,

Thanks for your input!

In answer to your comments/questions:

- Is there any way I can check the resistance of the ground myself?
How would I do that? (I have a digital multimeter kicking around
somewhere...)

- I am based in the country - no industry around for at least 12
miles.

- Noises are not related to the time of day.

- Lights are steady, but the alarms in other UPS units go off in the
morning. I do not use these particular units for audio.

UPS alarms going off regularly is a sign of bad power stuff. The
powerline analyzer will help you track that down and get on your
power provider to fix problems that they may be responsible for.
going every morning at about the same time is probably some
large piece of electric equipment starting up each morning.

--Dale