[amsat-bb] Re: Fm satellite Frequencies and Doppler

Zachary Beougher zack.kd8ksn at hotmail.com
Mon May 16 14:25:59 PDT 2011


I am not sure how you have it programmed into the radio so far, but I would 
program 5 memory frequencies into your HT:


436.805 (AOS)
436.795 (TCA - Time Of Closest Approach)
436.785 (LOS)

Since AO27 switches off way before LOS, you will probably never need the 
last frequency - 436.785 - but these would be the common frequency steps for 
a typical bird like AO51, SO50, etc.  Don't be afraid to make adjustments 
either.  I find that to hear the 30 sec. of TLM right before AO27 switches 
to VOX I have to be at 436.810.  This is probably more a feature of the 
radio itself.  If you are having trouble hear at AOS or LOS, try adjusting 
your downlink by 5kHz.

You can also add alpha-numeric tags to your frequencies to keep them in 


There are many different variations you can choose from.



-----Original Message----- 
From: Alexander Sack
Sent: Monday, May 16, 2011 4:23 PM
To: Clint Bradford
Cc: Clint Bradford ; amsat-bb at amsat.org
Subject: [amsat-bb] Re: Fm satellite Frequencies and Doppler

On Mon, May 16, 2011 at 3:50 PM, Clint Bradford <clintbradford at mac.com> 
>>> ... go to AMSAT's sat status page ...
> Personally, I prefer to get folks in the habit of checking the actual 
> control team pages for the various FM birds. That leaves any "middlemen" 
> and third=party Web site editing delays out of the equation.
> I mean, what better info is there than that published by those who 
> actually control the satellites?

I too am a beginner and wondered about how to calculate doppler and/or
determine a rough estimation based on pass information (elevation/az,
etc.).  I tend to start about 10 kHz up on any given pass which seems
to be a reasonable approximation for most of the birds so far (I
started this way because I followed the AO-27 FAQ).

My biggest challenge is finding the signal while adjusting for
doppler.  Once I get it though, I'm good for the rest of the pass!

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