[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: AO-40 squint



I just finished building a 4.5 turn helix to test with my dish. Next pass where
I'm home to test looks like this weekend, I should know then if the additional
turns make an improvement on higher squints.

73's

Don Woodward
KD4APP
AMSAT 33535
kd4app@amsat.org
http://www.w-ent.com/ao40/index.htm


----- Original Message -----
From: "Frederick M. Spinner" <fspinner@hotmail.com>
To: <dbwoodw@abraxis.com>
Sent: Monday, March 18, 2002 10:47 AM
Subject: Re: [amsat-bb] AO-40 squint


Common "Helix" knowledge would say that with your offset dish which probably
has a f/d of 0.7 that you should be running a 4.5-5.5 turn helix for optimum
illumination.

I just put in a post for an old Primestar dish, I'll let you know in a
couple of weeks what feed I'll use/what results I have with it.  It's
roughly the same as a 90cm offset dish in f/d, gain, etc.

Fred W0FMS


>From: "Don Woodward" <dbwoodw@abraxis.com>
>Reply-To: "Don Woodward" <dbwoodw@abraxis.com>
>To: "Amsat Bulletin Board" <amsat-bb@AMSAT.Org>
>Subject: [amsat-bb] AO-40 squint
>Date: Sun, 17 Mar 2002 08:26:41 -0500
>
>My current setup seems to capture 100% blocks/frames with good CRC's from
>AO-40
>when the squint is 20 degrees or less and the ratio of good to bad drops
>off
>dramatically after the squint increases above 20, so I usually quit trying
>to
>copy at this point - I am using a 90cm offset dish and a 2 1/2 turn helix
>and
>Transystem 3733. My system hears very well - last week I was able to copy
>the
>Helaps sideband noise. According to the "AO-40 S2 Squint Analysis by VK5HI"
>on
>the AMSAT web, it says that "Optimal error free downlink performance using
>the
>S2 downlink for telemetry captures occurs at squint angles less than 35
>degrees".
>
>My question:   Is anyone reliably coping blocks/frames with good CRC's at
>higher
>squints? Say 25 and up? How high?
>
>73's
>
>Don Woodward
>KD4APP
>AMSAT 33535
>kd4app@amsat.org
>http://www.w-ent.com/ao40/index.htm
>
>----
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org




<html></html>


_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp.



----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home