[amsat-bb] L/S helix feed

Joe Leikhim rhyolite at nettally.com
Tue Oct 24 12:29:35 PDT 2006

Bob; I don't think the larger reflector will hurt S-band feed although the larger reflector will create some additional blind spot for the dish. This may not be a problem depending on the gain required. Could you share pictures or drawings of the concentric feed? I am very interested in all options for multiband dish feeds.

Message: 3
Date: Mon, 23 Oct 2006 23:46:52 +0000
From: w7lrd at comcast.net
Subject: [amsat-bb]  L/S helix feed
To: amsat-bb at amsat.org
	<102320062346.26698.453D546C00022FD80000684A22058861720B9D04C999 at comcast.net>
Content-Type: text/plain

Questions on my current L/S helix feed.
I am building a dual L/S concentric helix feed for a 48x54 inch primestar dish.  The reflector is cut for  L band does that cause a problem with S band?  Where can I find a good design for a notch filter for S band to reduce desense?  Where does the focal point want to be on the helicies?  Or is it pretty forgiving.  Any other information is appreciated.
73 Bob W7LRD

Joe Leikhim K4SAT

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money"  ;-P

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