Aihnss.173
net.ham-radio
utzoo!decvax!ucbvax!ihnss!karn
Tue Oct 27 21:55:10 1981
Uosat telemetry info available
I have written a C program that decodes Uosat-Oscar-9 telemetry.
If anyone is interested, I'd be happy to mail it.

I would like to maintain a list of recipients so that I can send
corrections and/or updates.  If you get a copy of my program through
someone else, please let me know so I can send you updates.  I'd also
like to know who is listening for Oscar-9 and how much interest there
is in it.

For those of you who haven't listened yet: The new Oscar is
audible on a 2-m HT using a rubber antenna!  (Not inside buildings,
though). Listen on 145.825 Mhz, afternoons between 2pm and 4pm,
and you should hear the spacecraft.

Other items of interest to Uosat users:
1. I successfully copied 1200 baud ASCII telemetry last weekend.
Contrary to published specs, the spacecraft does NOT seem to invert
mark and space tones relative to the lower (<=300 baud speeds). A
standard Bell 202 modem works without modification both at 300 and
1200 baud.

2. The orbit of Uosat-Oscar-9 is so low that atmospheric drag is
causing significant errors in tracking.  For example, last weekend,
I observed the spacecraft running as much as 1/2 hour earlier than
predicted by a set of NASA/NORAD elements obtained only 2 weeks ago.
I am receiving current orbital elements both through AMSAT and NASA, and
will gladly send them to anyone who is interested.  I can also mail
copies of the BASIC program by Dr. Thomas Clark, W3IWI, Amsat
President, that takes these elements and generates tracking
information.

Phil Karn, KA9Q