Re: [amsat-bb] GRRRRRRRRRRR!

["Howard Long" <howard@xxxxxxxxxxxxxx>]

Hello Jim

The reason that they're at 45 degrees is for a number of reasons...

o	It's easier (takes less relays, therefore less losses) to phase switch
between RHCP, LHCP, Horizontal, Linear if you mount at 45 degrees. Check out
http://www.g6lvb.com/remotepolarization.htm as Christopher Cox has
mentioned.

o	If you have one horizontal and the other vertical rather than at 45
degrees, the two antennas are not 'symmetrical' and therefore an unequal
balance with other external metal bits and pieces, and the ground, so you
end up with a less well defined lobe.

o	Don't ask me why they're 2m apart. It just works that way though. I never
tried any other separation.

I took the theory of the ARRL Satellite Handbook and the RSGB Radio
Communication Handbook and put it into practice.

If you can't get up the biggest antennas for covenant or other reasons, you
have to make do with what you can - and having the option of phase switching
is beneficial from a radio perspective without upsetting the neighbors!

And empirically you can work every sat there is, analog and digital upto
9,600bps 100% guaranteed on a pair of Arrows and a 10m wire dipole (when the
sat's working that is!). OK, so AO-10 has to be < 15,000 km away.

Cheers, Howard G6LVB

-----Original Message-----
From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org]On
Behalf Of Cordill,Jim
Sent: 02 March 2001 14:57
To: 'John / NS1Z'; Christopher Cox; David M. Tipton
Cc: amsat-bb@AMSAT.Org
Subject: RE: [amsat-bb] GRRRRRRRRRRR!


That is a nice installation, but I can not quite make out how the arrows are
mounted to the boom at a 45 degree angle, any ideas?
Jim KI0BK

-----Original Message-----
From: John / NS1Z [mailto:ns1z@arrl.net]
Sent: Friday, March 02, 2001 4:58 AM
To: Christopher Cox; David M. Tipton
Cc: amsat-bb@AMSAT.Org
Subject: Re: [amsat-bb] GRRRRRRRRRRR!


Now that is a reallly nice installation. They still look to be linear
polarized, however. I think I have the same number of antennas in my back
yard as you have on your roof.... well, I might be short one dish. How can a
woman complain about that?????

Thanks for sharing the pix. If it ever gets above nothing (0 degree
farenheit!) around here I would like to get out and do some antenna work.
Summer usually happens around the last week of July or first week of August
here in Maine.

----- Original Message -----
From: Christopher Cox <cobox@urec.net>
To: John / NS1Z <ns1z@arrl.net>; David M. Tipton <tiptond@dnrconsulting.com>
Cc: <amsat-bb@AMSAT.Org>
Sent: Friday, March 02, 2001 1:38 AM
Subject: Re: [amsat-bb] GRRRRRRRRRRR!


> Here you go
>
> http://www.g6lvb.com/ultimate_arrow.htm
>
> Try thinking out of the box, gets lonely in there!
>
> :-)
>

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