21 Feb 2015

160m this evening so far

At the moment the best DX on WSPR TX ths evening using my FT817 (3 blobs) into the earth-electrode "antenna" in the garden is 853km to Denmark.

So far, since trying my earth-electrode "antenna" on 160m, I have received WSPR spots (reports) from 37 unique stations and results have well exceeded all expectations. Best TX DX the night before last was northern Spain.
at 23:03
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4 comments:

Anonymous said...

Hi Roger,

Interesting experiments, although the skeptic in me is thinking that the ground isn't really forming the bulk of the antenna. I suspect it's the interconnecting wire lying on the ground connecting the ground spikes that's radiating, like a very low Beverage antenna.

Googing 'Grasswire Antenna' will throw up lots of references to this sort of antenna.

Can you perform A/B comparisons with any other antenna that could be modelled along with the earth spike antenna ?

I'm thinking that a low Grasswire antenna main lobe would be about 10 to 20 dB down on a Vertical or Tee along its line of fire from feed point to far end termination. Back to front ratio on the Grasswire would be in the region of 10dB.

One other test would be to perform A/B comparisons with the far end ground spike connected and disconnected.

What antenna current can you obtain with the far end ground spike connected and disconnected (assuming you can match both to the TX).

Regards,

Martin - G8JNJ

Sun Feb 22, 10:48:00 am GMT
Roger G3XBM said...

Martin, I am not easily able to compare antennas. At MF (472kHz) and LF (136kHz) I am pretty convinced it is a loop but at Top Band and higher frequencies all bets are off! You could well be right.

Thanks for reading and commenting.

Sun Feb 22, 11:41:00 am GMT
Roger G3XBM said...

Whatever the theory, it certainly proves getting out on 160m WSPR can be done a number of ways and a big antenna down the garden is NOT needed.

Sun Feb 22, 11:44:00 am GMT
Anonymous said...

Hi Roger,

Agreed WSPR is an amazing mode for experimentation and opens up a lot of possibilities that would otherwise not be practical or feasible.

Keep up the good work.

Regards,

Martin - G8JNJ

Sun Feb 22, 12:14:00 pm GMT

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