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Re: So what antenna is better ?



I agree that a high-gain vertical is useless for satellites as the pattern
has to cover at least 5-45 degrees. 1/4-wavelength verticals are available
commercially.

73,

John
KD6OZH

----- Original Message -----
From: "Tony Langdon (ATC)" <tlangdon@atctraining.com.au>
To: "'Andrew Rich'" <vk4tec@tech-software.net>; "'John B. Stephensen'"
<kd6ozh@verizon.net>; "'Amsat-Bb'" <amsat-bb@amsat.org>
Sent: Thursday, August 18, 2005 22:32 UTC
Subject: RE: [amsat-bb] So what antenna is better ?


> > A vertical is second best for LEOs. The only disadvantage is
> > fading if the satellite is linearly polarized.
>
> Umm, from plenty of experience, a vertical is almost useless on 70cm, and
> this is the biggest cause of "alligators" on the Mode J FM birds in VK.
The
> problem is most commercially built verticals have too low an angle of
> radiation, because they're designed for radiation towards the horizon
(i.e.
> below 10 degrees).
>
> A 1/4 wave or other low gain vertical can work OK, however, though my
> personal preference on UHF is for something directional, as gain
definitely
> helps.
----
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