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Message-ID: <EB1DaSAc7kO5EwNC@pickmere.demon.co.uk>
Date: Sun, 4 Jun 2000 13:43:08 +0100
To: rsgb_lf_group@blacksheep.org
From: "M.J.Powell" <mike@pickmere.demon.co.uk>
Subject: Re: LF: Re: Aerial tests.
References: <4.2.0.58.20000601105903.0097a890@mail.pncl.co.uk> <000301bfcc87$d6d381a0$9dd699d4@w8k3f0> <OpcBAIA338N5EwXR@pickmere.demon.co.uk> <003701bfce1a$2a24f580$93fb88d4@w8k3f0>
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In message <003701bfce1a$2a24f580$93fb88d4@w8k3f0>, Dick Rollema
<d.w.rollema@freeler.nl> writes
>To All from PA0SE
>
>In an earlier e-mail I wrote:
>
>> >Computer program AO by Brian Beezley, K6STI, shows  for the L-antenna
>over
>> >medium ground  an almost perfect omnidirectional radiation pattern. The
>> >deviation
>> >from a circle is no  more than about 0.1dB.
>
>Mike Powell commented:
>
>> And yet did not Marconi use a vertical antenna with a long horizontal
>> wire to obtain directivity from Cape Race? When the original aerials
>> came down in a gale he found equal or stronger signal strengths using an
>> inverted 'L' with the arm pointing the right way.
>
>Mike,
>
>It depends on the length of the horizontal part af the antenna.
>
>Jim used only 42m.
>
>When the top is increased to 0.1 wavelength than a F/B-ratio of 2.23dB
>results.
>
>With a top of 0.25 wavelength F/B becomes 3.51dB.

Thanks, Dick

Considering the poor receivers in use at the time and the ratio of
vertical to horizontal (1:1?) I would have expected a bigger
improvement.

Mike 
-- 
M.J.Powell