Message-ID: <000801c1c5f3$1fd8a0e0$1700a8c0@home>
From: "Dave Pick" <g3yxm@wireless.org.uk>
To: rsgb_lf_group@blacksheep.org
References: <DDC408CAE72CD511827A0002A5131CD6D9F4B5@exc_wil08>
Subject: LF: Re: RE: Re: loops
Date: Thu, 7 Mar 2002 16:14:13 -0000
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Bill.

This sounds interesting. Are you able to model the "gain" of the loop
against a 350ft inverted L fed against a 350ft counterpoise? Same amount of
wire but not joined up...
I just remember the great fashion of using loops on 160 years ago, these
were in small gardens and were about 60ft long and 25 - 30ft high, small but
still better in terms of wavelength than what you're proposing. These never
seemed to work any better than the equivalent inverted L.
Time for some experiments... over to you Mal!

Understood about the Voltage (note the capital... oh dear let's not start
that again..) on the loop, agreed but you don't have a capacitor at the top
of a vertical. Sounds like you need one that'll stand 5kV and 25A, and be
weatherproof and adjustable.

73
Dave
G3YXM.

> For the typical high Q LF loop with 50ft x 50ft dimensions, the max
voltage
> is about 7 times lower than the voltage at the top of a typical 50ft
> monopole. With a loop conductor of #8 ga, or RG-8, the current at 1w is
> approx 1.2A. At a 400w the current goes up by 20x to 24A, which is no
> problem for these conductors.
>
> What really looks interesting for a loop installation, according to the
> math, is the effective power gain that can be achieved by stretching the
> horizontal dimension. On my property I can make this 350ft (if it were
> legal) because of this strange narrow "L" shape out back in the woods.
The
> effective power, then, increases 50x! Tried this for an hour at very low
> power (don't tell the FCC), and it works!
>
> My first TX loop article just appeared in the US Longwave Club's 'Lowdown'
> publication. The second is to follow next month.
>
> Bill Ashlock
>
>
>
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