[amsat-bb] Re: Spin rate and orientation for SO-50?

Tom Schuessler tjschuessler at verizon.net
Mon Apr 2 19:01:55 PDT 2012


Drew,

Thanks for the reply to my post.

It does seem to me that this bird (SO-50), does have a much faster rate of
change than the other satellites I have worked.  Thus judging by the amount
of twisting I have to do during one of it's passes as compared to what I do
or did for AO-51, SO-67, HO-68 or AO-27.  I am constantly flipping the Arrow
around whilst following it.  I do agree with the concept that at times and
on certain elevation passes, this orientation change of the satellite causes
some shielding of the antenna as in the course of a minute, I can go from
very legible copy to hearing nothing at all and then a minute or so later,
picking it up again.  

Since there is always someone out in the world who likes to analyze
seemingly trivial details, that maybe someone who has much more time than I
might be interested in the challenge of figuring this out.

Let's keep raising the funds for FOX-1 and other true communications payload
full on Amateur Radio satellites in order to provide more fun and
educational opportunities to the larger community around us.  Satellite
contacts at events like hamfests, schools and museums really get folks
excited and interested in STEM as well as Amateur Radio.

73 de Tom, N5HYP



-----Original Message-----
From: Andrew Glasbrenner [mailto:glasbrenner at mindspring.com] 
Sent: Sunday, April 01, 2012 2:09 PM
To: tjschuessler at verizon.net
Cc: amsat-bb at amsat.org
Subject: Re: [amsat-bb] Spin rate and orientation for SO-50?

AFAIK there is no telemetry available to decode spin rate from, but my hunch
from experience with AO-51 is that the spin is very, very slow. 
What we see is a combination of blocking of the downlink antenna by the body
of the spacecraft, and with portable ops especially, mismatched polarity on
the downlink. The best option is to be able to twist the antenna to peak the
signal many times through the pass.

With SO-50's particular implementation of PL, it's also VERY useful to have
full duplex to both peak your signal, and know if you are getting in or
QRMing anyone.

SO-50 is sort of like the old Russian RS birds. We don't know a lot about
the bits and pieces, but are sure glad it's there and working!

73, Drew KO4MA

On 4/1/2012 2:50 PM, tjschuessler at verizon.net wrote:
> Hello AMSATers,
>
> SO-50 with it's lower ERP  and apparent spin make it a more difficult bird
for the handheld guys to keep up with but not at all impossible.  I have
been curious though if anyone has information as to what the
spacecraft/antenna orientation is and what is the spin rate if any and how
that affects workability?  I find myself explaining the quirksof this bird
to folks and would like a little more intelligent set of answers.  Any
thoughts would be appreciated.
>
> 73 de Tom, N5HYP, today in DM93
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