[amsat-bb] Re: [eu-amsat] AO-7 report.

[John Hackett]

Drew,
         It is my understanding from recent correspondance with W3GEY/VK3GEY 
Jan King ...
(Jan 'built' AO-7) ... and earlier correspondence with N1JEZ Mike Seguin 
(AO-7 control operator) when I first posted the mail re: the timer last year 
.... that the timer is completely random when the satellite comes out of 
eclipse and since there are no imminent occurances of eclipse as far as I 
can see, I assume the mode will not change unless anything 'ontoward' occurs 
to upset the electronics.

High power *can* affect how the control systems behave ... (obviously, I'm 
not going to mention the command parameters or the power required).

If my assumption is wrong, I stand corrected. In either case, listening to 
the regular operators will confirm the mode.

The mode changes can be viewed at ... 
<http://www.planetemily.com/ao7/stats2.php>

The predected eclipse chart at ... 
<http://www.planetemily.com/ao7/Eclipse.php>

Perhaps other operators will obtain different conclusions from the above 
predictions.

Opinions are are invited.

That is, after all, precisely why we started the EU-Amsat reflector.

I CC'd this mail to the amsat-bb since the number of Stateside users has 
increased in the last 2 months and this information may be of interest to 
them too.

73 John.   <la2qaa at amsat.org>
...........................................................................................................................................

>From: Andrew Glasbrenner <glasbrenner at mindspring.com>
>Reply-To: eu-amsat at yahoogroups.com
>To: eu-amsat at yahoogroups.com
>CC: amsat-bb at amsat.org
>Subject: Re: [eu-amsat] AO-7 report.
>Date: Tue, 31 Jul 2007 11:18:04 -0400 (GMT-04:00)

>Every time this has happened in the past, several times over the past few 
>years, the 24hr timer has >activated, switching between A and B. There is 
>no reason to expect it won't again.
>
>73, Drew KO4MA
...........................................................................................................................................

>From LA2QAA.

>A study of the AO-7 eclipse charts for the last 3 years shows a progression
>toward non-elipse orbits in late 2007 - 2008.
>
>In effect, this means that AO-7 in all probability will not change mode
>unless anything untoward happens.
>
>It also means that we appear to have a permanent mode-B LEO linear
>transponder for the forseeable future ... providing operators follow the
>recommended operating proceedure.
>
>Please *do* decrease your power as the satellite approaches TCA to avaoid
>FM'ing.
>
>This not only helps the satellite, it helps the other operators in the
>passband.
>
>Don't be fooled by propagation anomolies. The mode-B transponder is working
>well and will continue to do so providing the alligators go and play
>somewhere else. Under normal circumstances you do NOT !! need a lot of
>power. Please use only the necessary to maintain adequate communications. 
>If
>you can't copy people adequately, you should improve your receiving
>capabilities rather than increasing your uplink power ... remember,
>aluminium is cheap and it's a lot more user friendly to everyone concerned
>.... with perhaps the exception of your neighbours.
>
>For all intents and purposes, AO-7 is a QRP satellite. Please treat it as
>such.
>
>73 John. <la2qaa at amsat.org>