You are right of course , but you have spoiled the fun of laying corridor
wires at dead of night in my pyjamas.
Try book a ground level room and a room on a higher floor directly above.
drop wire from up to down. Connect to radiator at ground level and via tx at
the upper radiator. Leave it in Beacon mode all night while sleeping in the
comfortable bed
Much cleverer people than I am can work out what floor the upper one should
be on to make this Gamma-match work on a 40 storey building.
Bryan
----- Original Message -----
From: "Peter Martinez" <[email protected]>
To: <[email protected]>
Sent: 24 June 2006 12:54
Subject: LF: Re: Top-fed LF antenna idea
> From G3PLX:
>
> I am sure Jim is right to say "it's not quite true..". As I suggested in
my
> reply to Brian, if a lot of the field lines just 'short-circuit' back to
the
> top of the tower, then there isn't going to be much contribution from
these.
> But I think it's possible to believe that if we have a small monopole
> sitting in the middle of a square ground area which is the size of the top
> of the tower-block, initially at ground-level, and we then raise it by
> jacking-up the tower underneath it, our transmitted signal will increase
as
> we do so.
>
> It's well-known that you can work a lot further by taking a 2m handheld up
a
> tower, but if you only think of surface-wave propagation theory, you would
> say that there wasn't any point in doing the same with a 136kHz
'hand-held'.
> If we can accept that the old Post Office work on the field-strength from
> ships is reliable (it's the height above the sea that counts, not the
height
> above the transmitter), and we understand the mechanisms involved, we may
> gain quite a lot by taking, not just a small vertical monopole but any
sort
> of metal object which can be deployed clear of the structure, to the top
of
> something tall.
>
> 73
> Peter
>
>
>
>
>
> --
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>
>
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