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Re: ISS SSTV



I think it was fairly well understood that this is an experimental SSTV
transmission from the ISS and that the downlink frequency is temporary. I
was not aware of the conflict between the international 145.800MHz 'all
mode' ISS downlink frequency and repeater services in Russia, having assumed
it was chosen for its worldwide availability, but now appreciate that there
is great on-going co-operation to make this a unique frequency for
ISS-to-earth communication. Another great facet of Amateur Radio. Perhaps
someone can explain the uplink diversity.

My concern is that putting voice, packet and SSTV all on one downlink
frequency is rather restrictive. I realise that, at present, equipment is a
limiting factor and that there is not enough kit to have all of the various
modes in use at once but this may change over time so we should be thinking
ahead and considering other frequencies or even bands (e.g. SSTV on 70cm).
In the meantime, we can only look forward to the launch of the Columbus
module with its additional ARISS facilities, including ATV (shame there are
no windows in the module), and feel secure in the knowledge that this is one
satellite that we can fix in flight should the need arise.

That said, I was disappointed to find out yesterday, listening to the EVA,
that it takes two years to get an engineer out to fix a computer on the
external truss. :-( And that Ivan Ivanovic (SuitSat-1) guy isn't much use
either! [http://en.wikipedia.org/wiki/Ivan_Ivanovich]

73 de

Félim M3HIM
IO91ot
Aylesbury, Buckinghamshire, UK
----- Original Message ----- 
From: "Frank H. Bauer" <ka3hdo@comcast.net>
To: <amsat-bb@AMSAT.Org>
Sent: Friday, August 04, 2006 12:55 PM
Subject: [amsat-bb] ISS SSTV


> All,
>
> The ARISS team does not plan to use the 144.49 downlink for SSTV for the
> long term.
>
> The ARISS team fully understands the Region 1 band allocations and wishes
> to abide by them.  It should be noted that amateur satellite
communications
> are allowed by ITU rules in the 144-146 segment.  The reason that we have
> different uplinks in different regions is that the three ITU regions do
not
> have consistent frequency allocations per mode.  As an international team,
> ARISS and many ham radio entities worked hard to clear as many systems
> (repeaters, APRS, etc) from the lower edge of the AMSAT Satellite band
> segment (145.80-146) as possible.  This enabled ARISS to have a dedicated
> downlink on 2 meters 145.80.
>
> Our Russian team members were running some initial tests on SSTV last
> weekend.  They utilized 144.49 for these initial tests because they wanted
> to do a full checkout of the SSTV downlink and there are still a few
> repeaters on 145.80 in Russia.  These tests were successful.  We
appreciate
> the amateur community's patience on this while our Russian colleagues
> were  running these tests.  Based on these initial tests, the ARISS
> international team has been working on some procedures for long-term use
of
> SSTV.  This includes the use of SSTV on the 145.80 international
> downlink.  As we get closer to final checkout of the system, you will see
> these changes made.
>
> Thanks for all your interest in ARISS.  We are looking forward to some
> exciting times as SSTV images once again beam down from space!!
>
> 73,  Frank Bauer, KA3HDO
> ARISS International Chairman
>
> -------------------------------------------------
> Message: 12
> Date: Wed, 2 Aug 2006 16:07:55 +0100
> From: =?iso-8859-1?Q?F=E9lim_Doyle_M3HIM?=
> <Felim.M3HIM@ntlworld.com>Subject: Re: [amsat-bb] ISS SSTV
>
> The 144.490MHz frequency being used on the ISS for the SSTV downlink is
not
> a valid satellite or SSTV frequency in Region 1 as it is just at the top
of
> the CW Beacon segment of the 2m band. So, if the ISS crew are on the ball,
> they should not have SSTV on when passing over the UK. However, they did
> have it on during one or more passes at the weekend when I was in the
GB4FUN
> bus at the AMSAT-UK Colloquium. We failed to capture a picture despite
> having a crystal clear signal and correctly decoding the CW
identification.
> It was possibly because the software was not set up for the correct mode
> (i.e. not Robot 36).
>
> There may be other opportunities over the coming days/weeks but, as I say,
> strictly speaking it should not be running over Region 1.
>
> 73 de
>
> Félim M3HIM
> IO91ot
> Aylesbury, Buckinghamshire, UK
> ----
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----
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