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Re: "Trash Can" or steel drum dish antennas



I remember watching the first night of the Telstar TV LEO transponder.

Here in the Uk we had a "normal" ?50 foot, dish antenna at Goonhilly in
South West England.

On the first pass, the signals were very weak and watery. Much scratching of
heads and then came the realisation that the antenna feed was the wrong
polarisation. 90+ minutes later the signal was back for 9/10 mins and at
full strength.

It was nighttime in the Uk and I still have a happy visualisation of some
engineer being sent up the focal point of the dish to fix the feed.

There is a film of the control room in existence somewhere in which the off
air pictures can be seen.

Jean Louis - I sometimes get to Brittany so if you have any detailed info on
the Museum that would be very interesting

73

Graham G3VZV

----- Original Message -----
From: <Jean-Louis.RAULT@fr.thalesgroup.com>
To: <amsat-bb@AMSAT.Org>
Sent: 05 December 2001 09:02
Subject: RE: [amsat-bb] "Trash Can" or steel drum dish antennas


Such a huge hog-horn coupled to a maser amplifier was used in France during
the sixties to perform the first USA/Europe TV direct-live satellite
transmissions.
The antenna and its radome are still there in Britanny (west part of France)
and have been converted into a telecommunications museum.

73 de Jean-Louis F6AGR

> -----Message d'origine-----
> De: Alfred Green [mailto:nu8i@home.com]
> Date: mardi 4 décembre 2001 16:28
> À: amsat-bb@AMSAT.Org
> Objet: Re: [amsat-bb] "Trash Can" or steel drum dish antennas
>
>
> Scott Townley wrote:
> [snip]
> >
> > As an aside, anyone ever heard of a "cornucopia" antenna?
> Some of the
> > old long-haul analog microwave sites run by the old AT&T
> still have some
> > up.  They are generally a cone pointing up with an "elbow"
> opening that
> > opens to the horizon.  Those have even better sidelobe/backlobe
> > performance.  I have some pictures in old textbooks; they
> appear to be
> > one of the original radio astronomy antennas.  And now
> they're all dark;
> > someone needs to pull one down and fire it up!!
>
> I dont recall the term "cornucopia", but from the name and description
> it sounds like what we used to refer to as a hog-horn. If I ever knew
> the derivation of that term it is long lost in the shower of discarded
> brain cells.
>
> As I recall, it was essentially a parabolic section with a horn feed.
> The sides of the horn carried on to provide side walls for
> the parabola,
> reducing the sidelobes. It had a reputation for being a
> 'quiet' antenna,
> hence the radio astronomy connection.
>
> PA0AVS has built one for use on 432 & 1296 EME; there's a
> picture in the
> antenna gallery on Rein's site, http://www.nitehawk.com/rasmit/
>
> An S-band version would be fairly compact, and give a good G/T ratio.
>
> Definately food for thought.
>
> 73  Alf  NU8I
> Scottsdale AZ DM43an
>
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