Underground Antenna Experiments on 160 meters.
Reg Edwards
Some years back I buried a 30 metre (60-feet) auminium wire one spade
depth in my back garden. Wire was 1.5 mm in diameter. Soil
resistivity about 100 ohm-metres. To scientists that's 10
milli-Siemens. The near end of the wire came up in the shack. That's
under my kitchen sink. It's still there. Open-circuit at the far end.
As a counterpoise, something essential to tune it against, I erected a
wire in the form of an inverted-L. This was about 30 feet high and
overall length about 140 feet. I chose this length because it fitted
nicely into my back garden. The front garden is too short even for an
underground antenna.
On the 160m band I fed into it about 30 watts from a home-brew
transceiver so I can't provide for the record a manufacturer's type
and serial number. However I still have the transceiver which can be
inspected.
Despite a high local noise level of S-6 I was able to communicate up
to 60 miles with mobile stations in broad daylight on SSB. After
sunset I could easily communicate with most of Europe on CW.
I think a record of these buried antenna experiments should be kept
for posterity, alongside the famous biblical work of B,L & E.
By the way, as you see, I did remember to measure soil resistivity. It
was the first thing I did. What buried wire do you think I used to
measure it?
----
Reg, G4FGQ
jgbo...@aol.com
Hi Reg, Interesting, but isn't a 30 metre wire more like 100 feet
instead of 60 feet? According to the conversions on your programs it
is. Did you ever try burying your counterpoise and elevating the
buried aluminum wire to see how the results compare?
Gary N4AST
Reg Edwards
<jgboyles wrote
> Hi Reg, Interesting, but isn't a 30 metre wire more like 100 feet
> instead of 60 feet? According to the conversions on your programs
it
> is.
It's in the right ball park.
I'm pleased you make use of the measurements conversions in some of my
programs. Its just a small thing I can do to help paying back for what
you Americans did by helping us poor Brits to win the war. ;o) ;o)
;o) ;o) ;o) ;o)
----
Reg.
Richard Fry
>Some years back I buried a 30 metre (60-feet) auminium wire
>one spade depth in my back garden.
> wire in the form of an inverted-L. This was about 30 feet high and
> overall length about 140 feet.
>I think a record of these buried antenna experiments should be kept
>for posterity, alongside the famous biblical work of B,L & E.
____________
So you loaded your tx into an antenna system consisting of a 140 foot
inverted L, 30 feet above ground with a buried ground radial 99 feet long.
What is so unusual about that? Certainly not a venture of biblical
proportions, IMO.
Perhaps you haven't flipped enough of your calendar pages?
RF
John Smith
Indeed, my grandfather fought with "you brits" during the war, he had many
german lugars, swords, coins and memorabilia he brought back...
He seen enough to hold a high respect for the british empires' citizens--for
the rest of his life... indeed, his words inspired such in others...
Unless he greatly exaggerated the acts of glory, valor, bravery and loyalty
demonstrated by the british troops, (which I never found existed in my
grandfather--exaggeration), which he shared foxholes with, you brits have
nothing to repay... we are even--perhaps we even got the better of the deal, as
our forefathers had the company of decent men to share those bad times with...
he was there and liberated the Nazi camps, in the end... he would cry when he
would describe what his eyes could never forget...
... he spoke highly of the aussies also, indeed, he commented, "some of those
men were above mere human beings" (his EXACT words), when referring to both
brits and aussies.
I have told my son of this man (his great-grandfather) and the men he (my
grandfather) was fortunate enough to have had at his side...
If the future demands, let us hope we shall be such allies again...
John
"Reg Edwards" <g4fgq...@ZZZbtinternet.com> wrote in message
news:dcbmq4$4c7$1...@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
Cecil Moore
> I'm pleased you make use of the measurements conversions in some of my
> programs. Its just a small thing I can do to help paying back for what
> you Americans did by helping us poor Brits to win the war. ;o) ;o)
> ;o) ;o) ;o) ;o)
Hey Reg, guess where our English system of
measurements came from.
--
73, Cecil http://www.qsl.net/w5dxp
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Rex.T
wrote:
>Hey Reg, guess where our English system of
>measurements came from.
The Romans, the same as ours
Rex. T
Murray
sand in the desert and successfully transmitted some
thousands of miles to the disbelief of the receiving
stations. No measurements of any scientific stuff
like soil conductivity, but. :-)
Cheers
Murray vk4aok
GS
My partner has built a similar antenna years ago with great success.
There are several antennas of this type in the world used primarily for
military applications at the these bands.
If anyone is interested look at www.ve3sqb.com, maybe you can get him to
post some of his research.
73's
Guenther VE3CVS
Degen Designs
www.degendesigns.com
in...@degendesigns.com
"Reg Edwards" <g4fgq...@ZZZbtinternet.com> wrote in message
news:dcbipg$c94$1...@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com...
Harold E. Johnson
> Reg Edwards wrote:
>> Some years back I buried a 30 metre (60-feet) auminium wire one spade
>> depth in my back garden. Wire was 1.5 mm in diameter. Soil
>> resistivity about 100 ohm-metres. To scientists that's 10
>> milli-Siemens. The near end of the wire came up in the shack. That's
>> under my kitchen sink. It's still there. Open-circuit at the far end.
Reg, was that 30 meters and 90 feet or 60 feet and 20 meters? Just for us
mathematically challenged.
W4ZCB
Reg Edwards
for us > mathematically challenged.
>
> W4ZCB
>
Harrold,
To be exact, 30 meters = 98.43 feet.
It was NOT a deliberate mistake to check on how much interest would be
displayed in the experiment by readers. But it could have been. ;o)
I did swap the connections between antenna and counterpoise and, as
you can guess, it didn't make a scrap of difference.
The underground antenna ended up in a bunch of other radials. But the
best radial I have is the incoming domestic water main which is
terminated at its other end by 100,000 miles of underground pipes
feeding the whole of the Black Country (where it all began) and the
Great City of Birmingham (which yesterday suffered a tornado due to
Earth warming climatic changes caused by American pollution of the
atmosphere).
It was only the day before that life in the city was disrupted by
police raids on houses alleged to be occupied by unsuccessful suicide
bombers. Birmingham, in opposition to Manchester, will do anything to
get into the news!
----
Reg.
M. J. Powell
Edwards <g4fgq...@ZZZbtinternet.com> writes
It has to.
Mike
Roy Lewallen
vertical counterpoise, and AM broadcasters have been using this
technique for the better part of a century. Works fine. Hm, maybe I
should add another column to the wire specification table in EZNEC so
people can specify whether the wire is an (A)ntenna or (C)ounterpoise. . .
A related antenna was described many years ago in one of the amateur
magazines. The author explained that when we construct a vertical
antenna, an image antenna appears in the ground. So he simply dug a hole
in the ground in put his vertical below ground. The image antenna did
the radiating, of course. I did a pretty thorough search of QST and
couldn't find the article -- I'd be indebted to anyone who can recall
where this appeared. My guess is that it was around the early '60s. In
an April issue of course.
Roy Lewallen, W7EL
John Ferrell
(Bill) may have written it. However, I was thinking it more in the mid
60's.
de W8CCW
On Fri, 29 Jul 2005 12:51:56 -0700, Roy Lewallen <w7...@eznec.com>
wrote:
John Smith
I can't even dream of burying a perfectly good, working, beautiful, sleek
antenna!
... I shall refrain from burying any antenna, before its' time ...
John
"Reg Edwards" <g4fgq...@ZZZbtinternet.com> wrote in message
news:dcbipg$c94$1...@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com...
>
Michael
interested in the sand antenna. I would love to hear more about working
antennas that exist entirely below ground. I am guessing but would say this
would not work on any band above 160 meters. I know the Navy has made huge
underground radiators at frequencies like 50 khz. I would be surprised to
hear that something as high as 1.8 mhz could be made to work.
"Reg Edwards" <g4fgq...@ZZZbtinternet.com> wrote in message
news:dcbipg$c94$1...@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com...
>
Hal Rosser
utilities" - he got tired of burying those telephone poles so deep! And I
had to give up chicken farming because the county extension agent said I was
planting them too deep - I think I must have been planting them too near the
underground power lines.
"John Smith" <assembl...@gmail.com> wrote in message
news:2DwGe.90$Va1.2...@news.sisna.com...
Hal Rosser
back in.
ground loops get hairy sometimes.
Irv Finkleman
>
> Hi Reg, Interesting, but isn't a 30 metre wire more like 100 feet
Perhaps Reg took into account a velocity factor for sub-ground aluminum wire?
Irv VE6BP :-)
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
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--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada
jgbo...@aol.com
the
> Great City of Birmingham (which yesterday suffered a tornado due to
> Earth warming climatic changes caused by American pollution of the
> atmosphere).
>
Birmingham, in opposition to Manchester, will do anything to
> get into the news!
> ----
> Reg.
Hi Reg, I live in the Great City of Birmingham, and there was no
tornado yesterday due to Earth warming climatic changes caused by
American pollution of the atmosphere. We do have tornados here from
time to time and have even before the American pollution of the
atmosphere.
Of course I live in B'ham Alabama USA so I am closer to the pollution
than you are. The company I work for has spent billions on
environmental projects as has a number of other companies. It is
starting to make a big difference in the air quality over here. I
doubt seriously the B'ham tornado was anything out of the ordinary (1
every 100 years).
If you want to see who is really cranking out the pollution, look at
third world countries who are attempting to progress, which takes
energy that they can not afford, much less any pollution control.
China comes to mind.
Gary N4AST
John Smith
:| <- confused, stiff upper lip
I'll recover by the time of your next post. <grin>
John
"Hal Rosser" <hmro...@bellsouth.net> wrote in message
news:mFxGe.18961$h.1...@bignews6.bellsouth.net...
Roy Lewallen
> This has been done since the beginning of radio. Nothing new. However, I am
> interested in the sand antenna. I would love to hear more about working
> antennas that exist entirely below ground. I am guessing but would say this
> would not work on any band above 160 meters. I know the Navy has made huge
> underground radiators at frequencies like 50 khz. I would be surprised to
> hear that something as high as 1.8 mhz could be made to work.
I recall reading some years ago about underground antenna experiments
done by the military. I believe the were done well into the HF range. A
trench was dug, the antenna put into the trench but not in direct
contact with the soil, then the top was covered. The objective was to
make a concealed antenna for relatively short range communication. The
signals were much weaker than for an above-ground antenna (~30 dB if I
recall correctly, but I might not), but still usable for the purpose at
hand. This shouldn't be surprising.
Roy Lewallen, W7EL
Fred W4JLE
http://www.rexresearch.com/rogers/1rogers.htm
"Roy Lewallen" <w7...@eznec.com> wrote in message
news:11elmqa...@corp.supernews.com...
Roy Lewallen
> You might be interested in the 1918 article on underground antennas.
> http://www.rexresearch.com/rogers/1rogers.htm
Thanks for the reference. A key observation from it is:
"One of the Naval experts present mentioned that it had been found that
the penetration of the ground wave component increases with an increase
in wavelength. This is an important fact and helps to explain the
operation of this new radio system, with its aerials buried in the ground."
I believe this method is still being used for communications to
submarines. It depends heavily on the very great skin depth and
relatively low attenuation in sea water at the VLF wavelengths used.
The buried antennas I was referring to operate, as far as I know, with
normal field propagation through the air, not through the ground.
Here are the skin depth in feet and attenuation per foot in salt water:
Freq Skin Depth Atten
ft dB per ft
10 MHz 0.23 37
1 MHz 0.73 12
100 kHz 2.3 3.7
10 kHz 7.4 1.2
1 kHz 23 0.37
100 Hz 74 0.12
And here they are for average ground:
Freq Skin Depth Atten
ft dB per ft
10 MHz 13 0.66
1 MHz 25 0.34
100 kHz 74 0.12
10 kHz 230 0.037
1 kHz 738 0.012
100 Hz 2300 0.0037
So communication through the ground or even salt water is practical at
low frequencies. High frequency is another matter, though. But that
doesn't preclude using buried antennas for sky wave propagation.
Roy Lewallen, W7EL
Roy Lewallen
> I agree that it was an April issue and I think my old friend W8DMR
> (Bill) may have written it. However, I was thinking it more in the mid
> 60's.
>
> de W8CCW
My guess as to the date could easily be that far off. But if your friend
wrote it for QST or HR, he used a pseudonym -- I don't see his call or
name in the inclusive indexes of either magazine.
It must have been in CQ or 73. I can still recall the diagram, showing
the buried antenna and the dotted "image" above ground.
Roy Lewallen, W7EL
John Ferrell
a little bit where QST did (does?) not. I have been out of touch with
Bill since leaving the Central Ohio area.
As I recall, after he had one such artical published he received quite
a few letters from people who took it seriously.
de W8CCW
On Fri, 29 Jul 2005 21:20:08 -0700, Roy Lewallen <w7...@eznec.com>
wrote:
>John Ferrell wrote:
John Ferrell
I will use that at the next Lios Club meeting and aso in my church
newsletter...
de W8CCW
Fred W4JLE
submerged. They used a 13 mile array strung between 2 mountains. IIRC it was
on 18KC. CW only as any frequency shift would have put the finals out of
resonance. Much better methods today that remain classified.
I know we could receive it when submerged in the Red Sea.
"Roy Lewallen" <w7...@eznec.com> wrote in message
news:11elvqv...@corp.supernews.com...
> I believe this method is still being used for communications to
> submarines. It depends heavily on the very great skin depth and
> relatively low attenuation in sea water at the VLF wavelengths used.
>
> The buried antennas I was referring to operate, as far as I know, with
> normal field propagation through the air, not through the ground.
>
Ed Price
"Fred W4JLE" <w4...@w4jle.com> wrote in message
news:9ac$42eb929b$97d55eb8$31...@ALLTEL.NET...
Did the Navy ever deploy the Long-Range Autonomous Homing Bottle?
--
Ed
WB6WSN
El Cajon, CA USA
Reg Edwards
the same laws as propagation through anything else.
All is governed by the resistivity, permeability and permittivity of
the medium, at a partcular frequency, and the geometry of the
interfaces between different mediums.
The problem of finding solutions to paricular problems lies only in
entering input data into a general purpose, number crunching computer
program, which I'm sure versions of it already exist.
Roy Lewallen
> Roy. as you know, radio propagation through the ground follows exactly
> the same laws as propagation through anything else.
Sure. The only real differences among salt water, dirt, and air are the
loss -- which is a big difference -- and propagation velocity.
> All is governed by the resistivity, permeability and permittivity of
> the medium, at a partcular frequency, and the geometry of the
> interfaces between different mediums.
>
> The problem of finding solutions to paricular problems lies only in
> entering input data into a general purpose, number crunching computer
> program, which I'm sure versions of it already exist.
NEC-4 can handle antennas and propagation in two media of infinite
extent separated by an infinite plane boundary. Neither one has to be
air. While this doesn't imitate some real situations very well, it can
produce some good insights into propagation and the performance of
antennas embedded in a medium other than air.
Roy Lewallen, W7EL