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Re: AO-7 Emergency receiver



We should remember that not long after Oscar 7 and 8 AMSAT volunteers
developed a wonderful method of matching Nicads to prevent this sort of
problem.

Hence Oscar 11 with it's batteries still performing after 20+? years.

The amazing thing is that almost all of the rest of the hardware still seems
to be working.

So after all the recent debate are we really saying that the most popular
spec for a new Oscar would be a 10 watt Mode B bird in a  1200km sun
synchronous orbit with little if any software/ICs and a damn big solar
array?

Well it looks like there will be plenty to discuss/debate at the AMSAT-UK
Colloquium next month in Guildford!

Please excuse the plug and check out

http://www.uk.amsat.org/colloquium.htm

73 all

Graham G3VZV

----- Original Message -----
From: "SM0AIG" <sm0aig@hotmail.com>
To: <Richard@g3rwl.demon.co.uk>; <amsat-bb@AMSAT.Org>
Sent: 28 June 2002 19:13
Subject: Re: [amsat-bb] AO-7 Emergency receiver


The fact of the matter is that with an emergency receiver we would´nt have
to send up new satellites every second year so I don´t think there would be
a problem of frequency congestion. It´s just such an utterly waste of time,
money and effort to have a completely healthy satelite killed off by some
stupid battery short - a problem that could certainly be addressed one way
or the other. And if one would plan for a future on solar power only, the
sat´s behaviour would not be as erratic as that of today´s Oscar 7.

Maybe the designers at the time never realized that solar cells might have a
life span of 30 years or more. Yes, this is truly a matter worthy of some
debate.

Oscar 7 also has a near-perfect orbit for a LEO, at least on our latitudes.
It appears over the Stockholm horizon 10 times a day from 6 am to around 11
pm in 20 minute passes. That amounts to three hours of daily operating time.
And it stays that way until Xmas Eve both this and the next year.

Ingo / SM0AIG

Original Message -----
From: "Richard W L Limebear" <Richard@g3rwl.demon.co.uk>


> "SM0AIG" writes:
>
> > And the s/c
> > would live happily ever after, singing to us for decades.
>
> /Heresy mode ON
>
> But do we really want them all to stay on. Really. All of them. Sure,
theres
> some candidates for this (with 20/20 hindsight) but I'm not totally
convinced
> this would be a good idea. For a start we'd run out of frequencies for any
> new birds.
>
> /Heresy mode OFF
>
> Could make an interesting debate.
73
Richard W L Limebear G3RWL

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