LF: Re: 500kHz earth electrode loop - further testing today with step-up transformer

[Roger Lapthorn <rogerlapthorn@gmail.com>]

Could a possible mechanism to explain why this tiny "loop in the ground" works as well as it does be that it acts as coupling loop into the nearby phone lines? These connect into the house at the front and none come anywhere near the back garden. I can't explain why my signals propagate so well with such a tiny loop unless something like this is happening. Maybe I'm getting a "free ride" from this? Has anyone else experienced something similar?

Mind you, this does not explain why the direction of maximum ERP corresponds so classically to a true loop with the orientation of the loop I have.

73s
Roger G3XBM

On 20 June 2010 12:35, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:

Some very interesting results so far, but still not tried a step up transformer as the ones I've tried got hot.

Just tried this...

I've an earth rod just outside the back of the house, so I connected one end of the 500kHz TX to this ground rod and disconnected completely the wire to the ground rod down the far end of the garden. The other end of the loop was connected to the copper central heating radiator as before. The length of wire to the "outside the back door" ground is at most 7m long over the flat roof and down to the rod. What happened? Current in the loop is up 20%,  voltage is down 20% but I'm still being received by M0BMU and G0KTN (210km) with S/N within 2dB of the earlier "larger loop in the ground" set up!

So, what IS going on? Effectively all I have now is a short wire going to a ground rod outside the back door and the other end to the radiator, yet 5W from my 500kHz transverter is STILL getting halfway across England!

I'm now more puzzled than before why this arrangement works at all, let alone so well.

73s
Roger G3XBM

On 20 June 2010 10:23, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:

In the next few hours I've a new experiment on 500kHz WSPR using my earth electrode "loop".

A small step-up transformer should allow me to better match the earth loop and therefore increase the ERP some 4-6dB. To make a valid test I'll run the beacon for periods with and without the step-up transformer to see if a clear pattern emerges. You'll have to guess which is which.

So, (as always) I'll much appreciate any 500kHz WSPR reports today.

73s
Roger G3XBM

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G3XBM    GQRP 1678      ISWL G11088

-- 
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk

http://www.youtube.com/user/g3xbm
G3XBM    GQRP 1678      ISWL G11088