Topband: [Bulk] Re: HVDC

[Grant Saviers]

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
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>