Shifting gears all the way down to 60Hz and over to the magnetic field
exposure area.....
I had a set of high power, wire wound resistors in a bank to disipate
alternating 10 to 20KW of power off a 3 phase 480V bus.
It was a lame means to simulate a field oil pump load for the development of a
pump off controller.
At the end of the day I would run the set up to test out the power meter and
had the resistor array about 6 feet from where I would sit.
(yes I realize that was not smart arc flash wise...)
I found that I was feeling ill like the flu each day at the same time.
I looked at the arrangement of resistors and found that they were very much in
phase and possibly making a large mag field.
I decided that a CRT monitor close the coils would make a magnetic field
detector and found the display to become significantly distorted.
Perhaps there are better sensors but use what you have.
So I moved the array to the other end of the lab away from my desk and ran the
power meters serial link up to my work area to get away from the fields.
All the symptoms went away.
My co-workers said I was getting sick from the dust burning on the resistors
but I am still cautious.
Chris
From: Cortland Richmond <mailto:[email protected]>
About 25 years ago I had a 2 meter beam set up on a bay window next to the
shack. The antenna was actually about 10 feet above my head in the 2d story
room, but far enough from the attic roof to turn freely. Running about 200
watts, I discovered that pointing the beam North -and only North -- I got
terrible headaches when operating SSB.
Not on CW.
Some calculations showed exposure in that configuration was close to or a bit
over the then-current limit, or five times the Massachusetts draft statute. .
I doubt, however, that this was a thermal effect.
Some people who've met me (see you in August) may be thinking "THAT explains
it!"
Phooey on them.
Cortland
KA5S
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