Re: LF: Re: Aerial tests.

["M.J.Powell" <mike@pickmere.demon.co.uk>]

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