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From: "Ashlock,William" <William.Ashlock@edwards.boc.com>
To: rsgb_lf_group@blacksheep.org
Subject: RE: LF: RE: PART 2 (larger loops)
Date: Wed, 12 Jun 2002 13:00:57 -0400
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Hi Jim and group,

Jim, thanks for the picture of OH1TN TX loop setup. Not far off my "gone
wild" scenario. With a few refinements like an elevated return and a lower
Rac conductor that setup would blow a certain opinionated gentleman right
out of his boots!

BTW: I visited the old Marconi transmitting sight on Cape Cod last weekend
where he accomplished his first ocean crossing in 1906. Nothing remains but
the concrete piers for two of the towers - but such a beautiful isolated
spot, overlooking the ocean 100ft below! A diagram indicated he used a 45KW
generator to feed his spark transmitter, which feed a large loading coil
connected to a huge conical fan-out of wires to four wooden towers.
Apparently he sound of his rotating spark gap could be heard in the town 4
miles away! Kindof wondered why Marconi didn't experiment with loop
antennas. Anyone know of any old-time loop applications for long distance
transmission? Not long after this initial phase of early radio development
the technology shifted to much higher frequencies where the loop has less of
an advantage due to the smaller size of a 1WL loop. 

Bill A

   
>Dear Bill, LF Group,

At 12:34 31/05/2002 -0400, you wrote:
>PS: I was working in some numbers last night for a "loop antenna designer
>gone wild" scenario with 100w input. Using the max size for a loop of 1WL
at
>136k the width could be .65 mi and a height of 100ft.

Compare with what Reino, OH1TN uses - a LW antenna 28m high and 500m long, 
self-resonant close to 136k (see http://gamma.nic.fi/~oh9ufo/136ant.gif). I 
don't know if anyone has tried to measure the ERP, but with 100W TX power, 
he certainly puts out one of the best signals around.

If we all had antennas like this, 1W ERP would be too easy!

Cheers, Jim Moritz
73 de M0BMU


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