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RE: LF: RE: Earth antenna transmissions on a guide rail?!??

To: <[email protected]>
Subject: RE: LF: RE: Earth antenna transmissions on a guide rail?!??
From: "Marcin" <[email protected]>
Date: Tue, 24 Jul 2018 20:59:37 +0200
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Hello Stefan!

 

The signal-to-noise ratio of the movie is very good. The experiment is interesting and inspired me.

 

In January we tried to transmit on 8.27 kHz from a horizontal loop antenna. Team SP5WPK, SQ5BPF and SQ2BXI stretch the 500m wire. Ground was very good, by the river. The effect was not good. Information about the experiment in Polish:

https://klubnl.pl/wpr/en/index.php/2018/02/10/nadawczy-eksperyment-z-duza-pozioma-antena-petlowa-na-827khz/

73! Marcin SQ2BXI

 

From: [email protected] <[email protected]> On Behalf Of DK7FC
Sent: Monday, July 23, 2018 11:18 PM
To: [email protected]
Subject: Re: LF: RE: Earth antenna transmissions on a guide rail?!??

 

Hello Marcin,

Oh, from LA3EQ, we know that man, at least from the LF/MF WSPR database. If i remember correctly he has been here ion the list some years ago.

Listening from an antenna which is so close to the road? Should sound funny.
But i've been a bit disappointed, he just connected the coax between two very close disconnected parts of the guard rail. First i thought he installed an isolated (!) wire of 8 km length. These two segemnts should form a very small ground loop only. Of course it will generate some signal voltage. The Alphas were visible too. But what about ZEVS and the Schumann's, if he's talking about 10 Hz?

Meanwhile i thought a bit more about the preparations. I think i'm going to use that 0.4 mm diameter enameled cu wire that i have laying arround here, about 2000m is available from the unwound part of the 2.97 kHz coil. For the first test on the 450m distant guide rails this should work reasonably. The DC resistance will be about 65 Ohm which could be a significant part of the overall loss, hopefully :-) But then i'll have an impression of the earth electrodes resistance.
So i need to prepare a GPS locked signal generator and PA and a suitable output transformer providing something between 50...350V at 8.27 kHz...

73, Stefan


Am 23.07.2018 21:28, schrieb Marcin:

Hello Stefan
A very interesting idea for an experiment.
Looking at the video below should get good results.

https://www.youtube.com/watch?v=sWsdaSmWg7E

73! Marcin SQ2BXI

 

From: [email protected] <[email protected]> On Behalf Of DK7FC
Sent: Sunday, July 22, 2018 8:28 PM
To: [email protected]
Subject: VLF: Earth antenna transmissions on a guide rail?!??

 

Hi all,

During the weekend i am in the Pfälzer Wald again which is such a nice place to be! I already installed a fixed E field antenna for VLF/ULF reception in JN39XI06 :-)

Now i have the idea to use a guide rail (attachment!) as an electrode for a earth electrode antenna! There is a perfect road which is not much frequented and where no way is crossing so i could temporary install a long wire on the ground between two of these guide rails. I would assume they provide a good grounding. They are located on a relatively high hill/mountain with stony ground. The mountain is very steep there and in some distance, 200m deeper, there is a brook..

With some luck the ground losses can be near 200 Ohm? Maybe rather 300 Ohm. I'm going to prepare things and plan to transmit for some time next weekend. If the ground loop actually acts like a loop, the bearing should be 135 deg, so it will be in a 45 deg angle towards my QTH where my grabber is listening in 55 km distance. That's quite a good distance for testing! I'd like to try LF and VLF, maybe ULF it all works well.

A BTW the wire length will be 860 m! However there are two guide rails in a shorther distance, about 450 m. I will try the shorter length first, to get an impression of the loss resistance and to see if something is visible at all :-)

73, Stefan

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