Message-ID: <3F2BE3B1.8030300@virgin.net>
Date: Sat, 02 Aug 2003 17:15:45 +0100
From: "Stewart Bryant" <stewart.bryant@virgin.net>
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To: rsgb_lf_group@blacksheep.org
References: <001501c358f0$32b7af80$75c428c3@bryan2>
Subject: Re: LF: Re: 500m drums of coax  dipole
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But compared to 2000m the 10 to 20m that most folks manage is still
small.

As I write this I look out at the farmers field behind my new house
reasonably high on the north downs. Perhaps I should take a reel of
cable down the edge of his field, and through the woods beyond.
I could not manage a dipole, but perhaps it is worth trying one of the
grounded at both ends, on the ground, loops that were talked about
in the early days.

Can anyone remember what sort of length one needs to start with?

Stewart G3YSX


captbrian wrote:
> Is there the slightest evidence that 136 propagates  (propogates?) by
> scatter or reflection.? I assume most of a 2" high dipole radiation goes
> straight up to Mars.
> 
> Bryan
> -----Original Message-----
> From: G0MRF@aol.com <G0MRF@aol.com>
> To: rsgb_lf_group@blacksheep.org <rsgb_lf_group@blacksheep.org>
> Date: 02 August 2003 11:47
> Subject: LF: 500m drums of coax?
> 
> 
> 
>>
>>>>Are you making a coax dipole for 136?
>>>>
>>>>73
>>>>John Rabson G3PAI
>>>
>>I've always wondered about dipoles / loops at 136k?
>>A 'dipole' just lying on rocky ground where the water table is many metres
>>below the surface could be quite effective. The angle of radiation would be
> 
> poor
> 
>>but the efficiency may not be as bad as first suppossed. One advantage of a
>>big antenna on the ground is that it can't fall down and, for the local
>>planning committe, it's less than 9 feet high.
>>
>>Some time ago I tried to simulate this by making a dipole for 21MHz and had
> 
> a
> 
>>number of QSOs through it while gradually lowering it's height and
> 
> retrimming
> 
>>as I went. I managed to work Romania were I sent "Ant dipole  5cm agl".  I
>>have no idea what the Romanian though of this madness and he didn't stay
> 
> around
> 
>>long to find out.
>>Incidentally, at about 2 inches off the ground the antenna was resonant at
>>about 20% less than it's normal 'free space length'. Never did find a big
> 
> field
> 
>>to try it on 136k.
>>
>>73
>>
>>David  G0MRF
>>
> 
> 
> 
>