LF: Re: More earth electrodes tests at 472kHz

[Roger Lapthorn <rogerlapthorn@gmail.com>]

As icing on the cake of this evening's experiment with earth electrodes, DJ8WX has just been copied on the 15m earth electrode "non antenna". Everything (PC, transverter and FT817 and SignaLink interface) was on battery supply and there is absolutely no connection to the mains earth or to copper pipes in the home. The vertical antenna is not resonant and is disconnected, so no mutual coupling likely. The last few reports (1754 until I went QRT just after 1800) were on the "all battery, 2 earth rods separated by 15m" set-up. Best report was from G0KTN at 210km, but I am pretty confident that much further is possible.

So, if anyone thinks they cannot erect a "proper" antenna for 472kHz I urge them to consider this idea. Clearly it will be many dB down on a proper large Marconi, but heck this is SO simple and the results are pretty decent for a 10W transverter output.

I shall resume 472kHz testing with the 2 earth rods set-up at bed-time - struggling to get enough internet signal to allow the PC to time sync in the rear downstairs study where currently set-up without all the internal doors being wide open, HI. I'll then leaving it running overnight.

Although the most likely explanation is "loop in the ground" H-field antenna I still don't quite accept this as the only mechanism. To get the results I do suggest the effective "loop in the ground" must be very large to receive the decent reports I do when compared with the Marconi, whose ERP I can reasonably well calculate. With wet, saturated soil, I find this "large loop in the ground" not really credible.  Is there any way this can also be considered an E-field TX antenna?

73s

Roger G3XBM

On 7 January 2013 17:33, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:

Yes I am Mike.

15m baseline between 2 earth stakes and a 12V battery. It does amaze me too.

QRT on 472kHz now until late this evening.

73s
Roger G3XBM.

On 7 Jan 2013, at 17:25, "Mike Dennison" <mike.dennison@ntlworld.com> wrote:

> Roger,
>
> If you are still using your earth antenna (1720UTC), your WSPR is an
> impressive -12dB S/N.
>
> de Mike,GXDV
>
>> Since 1608gmt I have been WSPRing with an even shorter earth electrode
>> "antenna" ( baseline about 15m) with BOTH ends connected to ground
>> rods in the soil. Max connecting wire height still 1.5m. Yesterday I
>> used the house pipes as one ground.
>>
>> Initial tests suggest reports are almost identical, suggesting the
>> true " loop in the ground" hypothesis rather than propagation aided in
>> any way by pipes. This is NOT the case at VLF.
>>
>> Most fascinating that this tiny "non antenna" works at all.
>>
>> 73s
>> Roger G3XBM
>
>

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