On Wed, 26 Jul 2017, 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.

The only hams that can use those LF bands in the US have special
permission, like the exemption given to early SSTV experimenters.

The ARRL had a notice just a few weeks ago about how the LF bands are
otherwise off limits until some issues have been worked out. It's related
to informing the power company or something like that. But it's not in
place, so the bands can't yet be used without that special authorization.
I'm not even sure if the FCC is issuing more of them.

We have the bands here in Canada though.

Michael