DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=googlemail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type;
        b=E3ptG1BMsqDhNUyztd/3BklWKCGZGWz2VCyECWnH3ua8ZeVk6aUJ9ioDwpKb0LDI+C
         A0ZvBMk5KVpZZsMsv6VejGavY3Ss9GHmdrnZK6iisMhH4HOJGgTzqd2sGmDJETPsNaMO
         ECALTC/6t+YjpkQ34uWWmwBoF0E0lB9R8exQc=
MIME-Version: 1.0
In-Reply-To: <E918823D7B4B44F3AC9244621C6123BC@JimPC>
References: <000a01ca9530$c4ee97a0$0401a8c0@xphd97xgq27nyf>
	 <E918823D7B4B44F3AC9244621C6123BC@JimPC>
Date: Thu, 14 Jan 2010 21:35:04 +0000
Message-ID: <fc7eccec1001141335i320023favda04d7a50c6a4790@mail.gmail.com>
From: Andy Talbot <andy.g4jnt@googlemail.com>
To: rsgb_lf_group@blacksheep.org
DomainKey-Status: good (testing) 
Subject: Re: LF: Re: 1/2 wave 500
Content-Type: multipart/alternative; boundary=001485f92230ff79f1047d26a82e
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


--001485f92230ff79f1047d26a82e
Content-Type: text/plain; charset=ISO-8859-1

That's how submarine communications antennas work on ELF (81Hz or
whatever).  A very long wire is grounded at the far end.  the skin depth of
poor conductivity ground results in a loop antenna with teh current
returning deep in the ground

Apparantly, a test was done in this country back in the 1960's, using a
section of  power grid line grounded at one end and a surplus power station
run up, loading into it - presumably at a frequency shifted away from 50Hz.


Sounds an interesting experiment although don't know what results were ever
found.   Think of the health and safety red-tape if anyone suggested
something like that, these days.

Andy
www.g4jnt.com

This email has been scanned for damaging side-effects by the health and
safety police, is guaranteed to contain no substances hazardous to health,
but may contribute to dissolving the nether and polar regions


2010/1/14 James Moritz <james.moritz@btopenworld.com>

> Dear Mal, LF Group,
>
> Interestingly, if you do an EZNEC simulation of this antenna, it produces
> an upwards-directed, horizontally polarised lobe as you would expect. But it
> also produces vertically polarised radiation upwards and "off the ends" like
> a loop. My guess is that it is also behaving as a long, thin loop, with the
> missing vertical legs replaced by the distributed capacitance between the
> wires and ground plane. It would be an interesting thing to try, but quite
> hard to evaluate the results, I think!
>
> Cheers, Jim Moritz
> 73 de M0BMU
>
>

--001485f92230ff79f1047d26a82e
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div>That&#39;s how submarine communications antennas work on ELF (81Hz or=
 whatever).=A0 A very long wire is grounded at the far end.=A0 the skin de=
pth of poor conductivity ground results in a loop antenna with teh current=
 returning deep in the ground</div>

<div>=A0</div>
<div>Apparantly, a test was done in this country back in the 1960&#39;s,=
 using a section of=A0 power grid line grounded at one end and a surplus=
 power station run up, loading into it - presumably at a frequency shifted=
 away=A0from 50Hz.=A0 </div>

<div>=A0</div>
<div>Sounds an interesting experiment although don&#39;t know what results=
 were ever found.=A0=A0 Think of the health and safety=A0red-tape if anyon=
e suggested something like that, these days.</div>
<div><br clear=3D"all">Andy<br><a href=3D"http://www.g4jnt.com">www.g4jnt.=
com</a><br><br>This email has been scanned for damaging side-effects by th=
e health and safety police, is guaranteed to contain no substances hazardo=
us to health, but may contribute to dissolving the nether and polar region=
s<br>
<br><br></div>
<div class=3D"gmail_quote">2010/1/14 James Moritz <span dir=3D"ltr">&lt;<a=
 href=3D"mailto:james.moritz@btopenworld.com">james.moritz@btopenworld.com=
</a>&gt;</span><br>
<blockquote style=3D"BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8e=
x; PADDING-LEFT: 1ex" class=3D"gmail_quote">Dear Mal, LF Group,<br><br>Int=
erestingly, if you do an EZNEC simulation of this antenna, it produces an=
 upwards-directed, horizontally polarised lobe as you would expect. But it=
 also produces vertically polarised radiation upwards and &quot;off the en=
ds&quot; like a loop. My guess is that it is also behaving as a long, thin=
 loop, with the missing vertical legs replaced by the distributed capacita=
nce between the wires and ground plane. It would be an interesting thing=
 to try, but quite hard to evaluate the results, I think!<br>
<br>Cheers, Jim Moritz<br>73 de M0BMU <br><br></blockquote></div><br>

--001485f92230ff79f1047d26a82e--