[net.audio] Interference comments

rjr@mgweed.UUCP (01/17/84)

I see Dave Burris received quite a few comments about correcting
interference. A few comments. for what it's worth:

I had channel 2 interference from a neighbor's CB rig 5 houses away.
I knew him well and knew he was within the 5 watt limit. I did some
calculations on expected field strength from the TV station as well
as his second harmonic making the assumption that it was something
like -40dB from the fundamental. Anyway the result was that his
second harmonic would still be stronger than the received TV signal!!
So he was legal but I was being interfered with. Although I didn't
pursue it, the FCC could possibly have made him do something (quiet
hours or ceasing altogether) but he was not really at fault. 
As it turned out, he was probably clobbering his own set since a few
weeks later he replaced his antenna and the problem went away. So
he indeed did have a problem of some kind.

My 2 meter ham repeater was bothered by strong bursts of what sounded
like raw AC every few minutes. This turned out to be the second harmonic
of some 15 kilowatt induction heaters in a factory a half mile away.
I contacted the company and they said "tough", so I wrote the FCC.
The FCC insisted they solve the problem pronto and send them weekly
reports of their efforts until I was satisfied the problem was cured.
They had a mfr's rep. retune them slightly. I don't know what part
of the spectrum they radiate in now but I am sure the intensity is
still the same. They also had been picked up by several repeaters
in Chicago, 40 miles away!

In general, the FCC will help with interference problems, if only to
supply the complainent with literature. I don't know about other states,
but in Illinois the FCC has only ONE field engineer, so they are not
going to drive out in their van for every complaint. (We could not even
get them to come out and take care of an unlicensed station operating
on the ham bands even after we found his location and had his name!!!!)

Bob, K9EUI