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-   -   Full wave antennae on 137kHz? (https://www.radiobanter.com/antenna/244624-full-wave-antennae-137khz.html)

Gareth's Downstairs Computer July 20th 17 08:14 PM

Full wave antennae on 137kHz?
 
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?


Graham.[_3_] July 21st 17 08:01 PM

Full wave antennae on 137kHz?
 
On Thu, 20 Jul 2017 20:14:24 +0100, 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?


If it does work, reciprocity is right out of the window.

--

Graham.
%Profound_observation%

Michael Black[_2_] July 22nd 17 01:13 AM

Full wave antennae on 137kHz?
 
On Thu, 20 Jul 2017, 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?


COnsidering that in the US the LF bands aren't yet available because they
need to deal with the power company using low frequencies over the power
line, you might end up causing interference.

But also, there was all that power line communication in the past
(university radio stations, intercomes, remote speakers and I forget what
else) but it stayed mostly on the power line. You needed to be relatively
close to the AC wiring to get the signal. Though maybe long distance
power lines are different.

Aren't you more likely to have success using a fence around a farm?
Though you need the right location, and maybe the right neighbors.


But what did they do in the old days? Everyone was down below the current
AM broadcast band in the early days, which is why hams were banished to
the "useless" shortwave frequencies. Did they have full length antennas
back then, or make do? They did try for long antennas but surely many
couldn't fit a full length antenna. But I'm sure lots of magazines from
the early days would turn up useful things, if you've got the space.

Michael



Bob Wilson July 25th 17 07:58 PM

Full wave antennae on 137kHz?
 
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

[email protected] July 25th 17 08:04 PM

Full wave antennae on 137kHz?
 
In rec.radio.amateur.antenna 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?


In most places using someone else's property without permission is concidered
a bad thing to do.

--
Jim Pennino

Gareth's Downstairs Computer July 25th 17 08:12 PM

Full wave antennae on 137kHz?
 
On 25/07/2017 19:58, Bob Wilson wrote:

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.


If I remember correctly from my time working on the design of
grid control systems (40 years and counting), it's known as
Pilot Protection and its loss may be the first indication of
a line going down.


Gareth's Downstairs Computer July 25th 17 09:06 PM

Full wave antennae on 137kHz?
 
On 25/07/2017 20:04, wrote:
In rec.radio.amateur.antenna 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?


In most places using someone else's property without permission is concidered
a bad thing to do.


How do you prevent your transmissions from passing through the
airspace of the countless millions whose permission you have not sought?


[email protected] July 25th 17 10:07 PM

Full wave antennae on 137kHz?
 
In rec.radio.amateur.antenna Gareth's Downstairs Computer wrote:
On 25/07/2017 20:04, wrote:
In rec.radio.amateur.antenna 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?


In most places using someone else's property without permission is concidered
a bad thing to do.


How do you prevent your transmissions from passing through the
airspace of the countless millions whose permission you have not sought?


A very different thing than "using a loop to couple into the electricity grid".

--
Jim Pennino

Gareth's Downstairs Computer July 25th 17 10:50 PM

Full wave antennae on 137kHz?
 
On 25/07/2017 22:07, wrote:
In rec.radio.amateur.antenna Gareth's Downstairs Computer wrote:
On 25/07/2017 20:04,
wrote:
In rec.radio.amateur.antenna 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?

In most places using someone else's property without permission is concidered
a bad thing to do.


How do you prevent your transmissions from passing through the
airspace of the countless millions whose permission you have not sought?


A very different thing than "using a loop to couple into the electricity grid".


Pretty much the same; using others' property to radiate.


[email protected] July 25th 17 11:09 PM

Full wave antennae on 137kHz?
 
In rec.radio.amateur.antenna Gareth's Downstairs Computer wrote:
On 25/07/2017 22:07, wrote:
In rec.radio.amateur.antenna Gareth's Downstairs Computer wrote:
On 25/07/2017 20:04,
wrote:
In rec.radio.amateur.antenna 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?

In most places using someone else's property without permission is concidered
a bad thing to do.


How do you prevent your transmissions from passing through the
airspace of the countless millions whose permission you have not sought?


A very different thing than "using a loop to couple into the electricity grid".


Pretty much the same; using others' property to radiate.


Not at all.


--
Jim Pennino


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