In message , Gareth's Downstairs Computer
writes
On 26/07/2017 16:33, Jim H wrote:
On Tue, 25 Jul 2017 13:58:27 -0500, in ,
Bob Wilson wrote:

On 7/20/2017 2:14 PM, Gareth's Downstairs Computer wrote:
Drove onto the field on Tuesday and was dismayed to
see a big banner marked Tomlinson, which portended
a bum job, but it turned out to be a scorcher being
a fence judge at the Dauntsey horse trials.

Taking my cue from the coupling loop that feeds a
mag loop antenna, and sitting pretty much under
the 400kV pylon line, I wondered about the possibility
of using a loop to couple into the electricity grid and
so giving the equivalent of a Beverage at 137kHz?

There is a lot yet to be fully understood about access to the LF bands
in the US. But if you are under a HV line, they might well be using the
line for carrying control signals for the power grid. The technology,
PLC, doesn't play nicely with ham usage.

How do you find whether a power line is using PLC? For some reason you
can't find anywhere a list of places that are OK, or that are not OK.
Instead you have go to a website and ask, and wait to be told yes or no.
So we (the hams) are in second place when it comes to sending
information over these lines.

(There is a fairly new line at something like 250KV close to my back
yard. I don't yet know whether it is carrying PLC.)
Bob Wilson, WA9D
As far as I know, in the USA we only have to inquire before
operating
if we're located within 1 km of a power line.


Whereas here in Brit we have restrictions within 1/2 mile of any aerodrome.

But that's a restriction on antenna height (40 feet, I believe - but as
I don't live within 1/2 mile of an airfield, I haven't checked lately).
--
Ian