Technical Topics > Equipment

Using the Earth as an Antenna

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The Hokie:

--- Quote from: Lex on November 05, 2011, 0238 UTC ---They were damned entertaining reading, a helluva lot more fun than reading most amateur radio hobbyist sites that argue endlessly about the merits of the T2FD and G5RV, or lack thereof.   ::)

--- End quote ---

I'm a lurker on a few vintage car forums, and not once have I seen someone bemoaning the fact that seatbelts were made mandatory in new cars. But it's fair game in ham radio :D

Pigmeat:
Troops on both sides of the Western Front in WWI used earth antennas for comms between the trenches. You've got to pump quite a bit of power into the ground,but it can be done.

I can imagine soldiers on both sides getting a nasty jolt in those muddy trenches when the CO ordered those spark gap generators fired up for urgent comms.

In the next war,one of the few ways American hams were allowed to operate was through ground antennas. From what I understand,talking to hams from that era,the range was very limited,a half-mile to a mile at best,depending on the soil and water table.

weaksigs:

While living in Vermont I had significant room for antennas and installed
some high, well tuned, wires especially for 40 meters. One of my favorite
activities was listening for DX stations during the “grey line”. However,
even in the Vermont boondocks noise can still be a problem at times. By
accident I discovered that running a length of insulated wire length
directly on the ground, I could often hear signals that were otherwise
buried in the noise. True my “S” meter didn’t go very high as signals were
reduced in amplitude, but noise was reduced at a greater rate, and in
some cases hardly discernible, permitting solid copy at times where the
same signals failed to be heard on a much higher well tuned antenna. I
discovered that an on ground antenna worked even when it was completely
buried in snow. On ground insulated antennas can be a pleasant surprise at
times especially on the “noiser” frequencies typically below 10 Mhz or so.

Its worth trying!

weaksigs

Zoidberg:

--- Quote from: weaksigs on November 07, 2011, 1505 UTC ---...By accident I discovered that running a length of insulated wire length directly on the ground, I could often hear signals that were otherwise buried in the noise.
--- End quote ---

Ditto.  Occasionally I'll tote a Sony 2010 portable out to the back yard to get away from household RFI.  But it's still fairly noisy because I can't get more than 50 yards away from utility lines in any direction.  I discovered by chance that an external antenna wire stretched out across the ground was much quieter than the same antenna tossed up a nearby tree.  As you've described, signal level is reduced but is much easier to copy due to a more favorable signal to noise ratio.

I've never had a chance to try the BOG (beverage on ground) or snake type antennas, but several folks report good results with them for coping with noisy conditions.

Pigmeat:
I use the Beverage On Ground system in the summer. Alan Maxwell of KIPM fame put me on to it years ago. For HF,100 feet of wire can be quite effective,but I like 200 plus feet to dig the tougher signals out.

The first time I used it,I was at a farm. Things are electrically quiet out there to begin with. I hooked the BOG to my Sangean 909 and the band went silent. I thought I'd fried the front end of the receiver until I did a bandscan on the 90 meter band. Most of those stations that the Brian Alexander guy logs in the mags and online,actually were there. I was sold. (Forgive me,Brian,for thinking you were full of it.)

It's amazing how just a bit of height can effect the noise levels. During the summer,on the ground,the BOG is very quiet. Raise it to 8-10 inches and the noise begins to become a factor. At a couple of feet the noise overcomes all but the flamethrowers.

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