aside from any possibility of interference from the lines as RFI, I wonder if
other types of interference might exist?
Perhaps being so close to the a)metal towers and or the (b) fields and
(c)wire(s) might effect your tx and or rx wave form shapes?
dunno
N2EHG
On Jun 1, 2012, at 10:07 AM, Jeff Blaine wrote:
> Related question.
>
> I'm looking to move to a place where I can put up a decent spread of
> antennas. A couple of the places have been scratched because the high
> tension lines were within 1000' or so of the potential QTH.
>
> This thread got me to thinking - can one assume a rough rule of thumb on
> distance to big lines?
>
> I realize the inverse square rule applies to any RFI problem that exists.
> Which argues a diminishing return in spacing - and concludes the further the
> better.
>
> On the other hand, I would guess the power companies would tend to want to
> fix any little thing found on the bigger lines because leakage or whatever
> on these big boys spells many problems for them. So it may not be as big of
> an issue as what one would assume?
>
> 73/jeff/ac0c
> www.ac0c.com
> alpha-charlie-zero-charlie
>
> -----Original Message-----
> From: K1TTT
> Sent: Friday, June 01, 2012 8:53 AM
> To: 'RFI Reflector'
> Subject: Re: [RFI] RFI from HIGH voltage power lines
>
> The 'beads' or 'bells' as they are usually called on the insulator strings
> are the key. As a rough guess you can assume 20-25kv line voltage for each
> glass or ceramic insulator bell in the string. So 10 of them would give
> 200-250kv, the common voltage used in that range in the states is 230kv. If
> the line is well maintained it should not generate much interference, but
> you must remember that it is allowed to generate a little bit, so close to
> the line won't be as quiet as farther away. If you can take a mobile
> station there during different weather conditions you could get an idea
> about how noisy the line might be.
>
> And yes, the 2 wires above the 3 heavy current carrying ones are for
> lightning protection.
>
> David Robbins K1TTT
> e-mail: mailto:k1ttt@arrl.net
> web: http://wiki.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://k1ttt.net
>
>
> -----Original Message-----
> From: Jim Miller KG0KP [mailto:JimMiller@STL-OnLine.Net]
> Sent: Friday, June 01, 2012 11:30
> To: RFI Reflector
> Subject: [RFI] RFI from HIGH voltage power lines
>
> Just wondering.... I have a few acres that run along HIGH power lines and
> wonder if it is even worth considering building a small weekend
> place/hamshack there. The antennas would likely be between 100 to not more
> than 250 feet from these guys.
>
> My question is whether RFI is more likely to be generated by these guys
> verses the smaller distribution lines along the average two lane blacktop
> rural road.
>
> These lines are the big guys. If any of this helps to identify the amount
> of power, here it is. Probably a quarter mile of more average between
> supports that are three poles each. Height is estimated maybe about 40 feet
> to the lines. There are three lines and the outside lines of the three are
> about 31 feet apart. There are 10 "beads" or "cones" making up each of the
> insulators the wires are hanging on. There are two cables running above the
> power lines (maybe for lightning to strike them instead of the power lines
> themselves?). Anybody have any idea of the voltage these would be carrying?
>
> Thanks es 73, de Jim KG0KP
>
>
>
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