I would suspect that a DC HV line operator will pay A LOT of attention
to any arcing from what I've seen of HV DC arcs. Once the ionization
gets established and metal ions vaporized from the terminals get flowing
it avalanches until the protection circuits act. Small AC arcs are much
different which leads to less interest in finding/fixing them. The
couple 100KV AC HV line near my QTH is pretty quiet. Lot's of rain
keeps the insulators pretty clean although noise does come up a bit when
some get wet.
Near my prior Bay Area QTH, PG&E helicopters washed the insulators a
couple of times a year as dust would accumulate on them and cause
problems, 380KV I think. Having had many passenger hours in a Jet
Ranger, it seems to me totally crazy operating one 20' from an energized
line. However, I didn't get to see a "HOT" repair via copter, only on
youtube:
https://video.search.yahoo.com/video/play;_ylt=A86.J7ugXtpUk3gAaJUnnIlQ;_ylu=X3oDMTB0c2puYm1xBHNlYwNzYwRjb2xvA2dxMQR2dGlkA1lIUzAwM18x?p=youtube+hV+transmission+line+service&tnr=21&vid=1269A35510213E2488651269A35510213E248865&l=191&turl=http%3A%2F%2Fts3.mm.bing.net%2Fth%3Fid%3DUN.608005122890599086%26pid%3D15.1&sigi=11rpbep1v&rurl=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DSkFH8lLvKZ0&sigr=11bgcu5vs&tt=b&tit=High+Voltage+Line+maintained+via+Helicopter&sigt=11b303tp7&back=https%3A%2F%2Fsearch.yahoo.com%2Fyhs%2Fsearch%3Fp%3Dyoutube%2BhV%2Btransmission%2Bline%2Bservice%26ei%3DUTF-8%26hsimp%3Dyhs-001%26hspart%3Dmozilla&sigb=13ger94lf&hspart=mozilla&hsimp=yhs-001
Makes free climbing look completely safe.
Grant KZ1W
On 2/10/2015 10:06 AM, Tom W8JI wrote:
Through the center part of Illinois they have begun work at the
government level to install a 690,000 VDC power line As with all this
there is huge amount of opposition an even groups trying to ban it
Does anyone have any experience with a line of such high VDC as a
noise source ? It will pass within 3/4 of a mile south of my QTH
I am really concerned my only hope if this goes thru is to pull up
stakes an move rather than attempt to fight its noise
Any thoughts
I think people are being silly.
Not only has there never been any evidence (beyond some fraudulent
thing that created hysteria) that power lines ever cause health
problems, a dc line has much less radiation.
As far as Ham radio, a dc is far less problematic for noise. 690 kV
dc is like 487 kV ac, except the line doesn't have the charging and
discharging issues that generate a lot of noise in bad connections.
The only possible issues would be noise at the dc-to-ac converters,
but they might be miles from you.
I wouldn't worry, and I would not support those who worry about other
issues like safety or health.
73 Tom
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