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Re: FM sat frequencies?



The frequencies given for each of the easy satellites are:

AO-27    436.795
SO-50    436.795
AO-51    435.300

AMSAT gives the details for the individual satellites and their uplink and 
downlink frequencies.  Go to the following site and then simply click on the 
satellite you are interested in. 
http://www.amsat.org/amsat-new/satellites/status.php

With doppler shifts as the satellites make a pass the actual receive 
frequency could vary by as much as about 10 KHz plus or minus the nominal 
frequency.  The only time you would ever receive the satellite exactly on 
its downlink frequency would be when the satellite heading is exactly 90 
degrees from your bearing to the satellite.  At that point the satellite is 
tangential to a circle whose center is your location and is neither moving 
toward or away from your location.

I am using an IC-910H.  For manual tuning at the beginning of a pass, I 
simply tune about 5 to 9 KHz higher (depending on the elevation of the pass) 
than the nominal frequency.  With the AFC turned on, the radio will 
automtically lock into the signal when it becomes strong enough and track 
the frequency as the doppler shift changes the receiving frequency during 
the pass.  At loss of signal, the receive frequency will be below the 
nominal frequency by about the same amount it was above at the start.

John Kopala
N7JK

> Date: Sun, 9 Sep 2007 19:44:15 -0700 (PDT)
> From: Bob Stewart <bob@evoria.net>
> Subject: [amsat-bb]  FM sat frequencies?
> To: Amsat-BB <amsat-bb@amsat.org>
> Message-ID: <869490.76831.qm@web909.biz.mail.mud.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> Does anyone know the actual downlink frequencies of the
> easy sats?  From messing around with my hack for gpredict,
> I get the values below, but it would be nice to know the
> correct values as a check against what I'm doing.
>
> AO-27     436.7972
> SO-50     436.7920
> AO-51     435.3008
>
> Bob - AE6RV


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