I recently looked at several sites in 7 land with the same concern. It
seems there are power lines everywhere! I used a mobile rig, LDG
tuner, and whip antenna to measure noise on several bands, which is
probably is the "proof of the pudding". I also used the "SignalHound"
USB spectrum analyzer, its averaging mode is very helpful in finding the
noise level.
One WA site has a MAJOR switch yard joining 3 very high voltage
transmission systems about 2000 feet away, yet the noise level was
incredibly low, <S1 and at the noise floor of the spectrum analyzer. I
could hear weak Europeans on 20m that weren't there at other sites.
Either this is good VHV transmission system design and maintenance by
the power company and/or the northwest rains keep the insulators clean.
This neighborhood had all underground utilities and 5 acre lots and
others have suggested that the low housing density and buried utilities
are the really important considerations. Noisy PCs, switching power
supplies, appliances, etc. may be the bigger concerns.
My CA QTH has a single HV transmission line 2000' east and I can not
hear it on 20m with my A4S beam pointed directly at it. Otherwise, this
direction has zero residences. However, when I point west at SiVly,
which is also where my overhead 18Kv(?) line feeds the residence pole
pig, I sometimes get S5-6 noise on 20m, bummer to work the VKs and ZLs.
I had PG&E survey the site for arcing and they claimed they were clean.
I recently discovered a noisy (arcing) pole about 1.5 miles away, so it
may be the source, or it is just the 2 million people the beam sees in
that direction?
Near salt water, you may suffer greatly from salt residue on the
insulators. I remember HV lines near the beach where the ACOUSTIC noise
from insulator (every one) leakage was objectionable! Forget about
listening to AM radio. You might ask around to check how often the ones
near your site are sprayed. The CA power line I can see is helicopter
cleaned a few times a year. From May to October there is no rain, only
dust accumulates on the insulators as salt water mist is not a concern.
Best to go measure your site with a mobile rig. I hope it is quiet.
I'm building the ultrasonic arc detector from QST April, 2006, by
W1TRC. google "ultrasonic arc detector" and you will get hits for the
pdf of the article and FAR Circuits for the PCB. I plan to use a down
rev DirecTV dish rather than spending the bucks for one from Edmund
Scientific. An AM radio will get you in the ballpark of an arc and his
gadget promises the capability to pinpoint the source.
Grant
KZ1W
Cqtestk4xs@aol.com wrote:
> I'm looking for land in the Tampa Bay area and have hit upon a 30 acre
> parcel very nicely priced. However, scanning the area with Google Map I
> found
> a BIG power line running east to west to the north of the property by
> about 2500-3000 feet at the closest point. Of course this is the worst
> direction for contesting. It appears, judging from the size of the
> transmission
> line towers, to be maybe a around a 100 KV run.
>
> Any thoughts on this line being as close as it is? Any first hand
> experience with lines this close? I intend to check out the property first
> hand
> when I hit the mainland, but I value members' of this reflectors opinions.
> I want to be able to hear signals not RFI.
>
> Bill KH7XS
>
>
>
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