That table didn't come out very well at all. Here's a link to the pdf:
https://sdellington.us/hr/RFI/Power%20Outage.pdf
73,
Scott K9MA
On 1/31/2023 11:21 PM, K9MA wrote:
My QTH is in an older residential area, surrounded by overhead power
lines. Line noise is a constant problem. We recently had a major power
outage, so I measured the noise levels to get a baseline with little
line noise. (See below, assuming it comes through.) The outage was
pretty large: there was no power within a kilometer or so, perhaps
further to the west. The levels I measured shortly after power was
restored the next morning are fairly typical lately. To the NE, it
wasn't so bad, only increasing 5-8 dB when the power came on. West was
much worse, 7-19 dB. I've long known there was a major noise source to
the west. I guess it's time to track it down.
I suspect these levels are fairly typical of a residential area with
overhead lines. They would probably be worse if I hadn't been doing
battle with the utility for the past 30 years to get the worst of the
sources fixed. One thing this data shows, which I've long suspected,
is that the distribution lines are the major source of noise. There
are some transmission lines just a few hundred meters away, but I've
never traced any significant noise to them.
It may say something about the sad state of our utility's
infrastructure: A car knocked down a pole about 1 km from my QTH, and
it took out the power up to 2 km away, with power surges causing
extensive damage to appliances, etc. (None at my place.) Just down the
street, far from the downed pole, we had a major fireworks show and
nearby a transformer exploded. Apparently, similar things happened
throughout the affected area. Did they forget the fuses?
73,
Scott K9MA
--
Scott K9MA
k9ma@sdellington.us
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