[TowerTalk] High voltage transmission lines

[Terry Conboy]

At 11:32 AM 2007-10-21, Steve K8JQ wrote:
>A possible home site I'm looking at is situated between two high voltage
>transmission lines. The two transmission lines run roughly east-west and
>are approximately parallel to each other.
>
>The transmission line to the north is either 345KV or 765KV (I received
>conflicting information) and was constructed in the 1990's. It is about
>800ft distant from the home site.

This echoes the comments from Roger, VE3ZI.

I worked for an electric utility in Oregon in the 1980's and if I 
were you, I'd stay far away from lines with anything close to 500 
kV.  All these lines exhibit corona, which is especially pronounced 
during precipitation or heavy fog.  The corona generates incredibly 
loud noise, both audibly and in the RF spectrum.  The noise is worst 
in the low bands and declines at higher frequencies.

The original designs for 500 kV lines used a single conductor per 
phase, but they made so much noise that even VHF TV reception was 
affected for nearby homes.  Newer lines use two or three spaced 
conductors per phase to lower the voltage gradient and reduce the 
corona, but they are still bad.

We had a 500 kV line with two-conductors per phase from a generating 
plant in eastern Oregon.  It passed about 1/4 mile from a ham who 
liked to ragchew on 80m SSB.  Fortunately, that's a pretty dry area, 
but anytime it did rain, he had to shut off his radio in disgust.  He 
filed complaints (with the PUC, I think), but there really wasn't 
anything to be "fixed", unless you think that shutting down a 550 
megawatt plant or relocation assistance (for the ham) would qualify as a fix.

73, Terry N6RY