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Re: Misuse of the satellite bands




Hello Ib.

13 Jun 00 10:02, you wrote to 'amsat-bb@amsat.org':

 IC> Sangat, 9M2SS, ask about a monitoring service for satellites. I had
 IC> written this before I saw that message - but here is a little about
 IC> what I have heard over the last couple of weeks.
 IC>
 IC> It has been a pleasure to use the FM satellites over the last
 IC> many years with many new stations active.

Same here.  Now that UO-14 and SO-35 are active, we can get into the action
down here.

 IC> AO-21 was a very usefull bird in the "good old days".

Sadly, I never wored that one.

 IC> Now we have the use of AO-27, UO-14 and SO-35, which all are
 IC> working very well.

Same comment for here, minus AO-27.

 IC> Personally I have worked 81 new stations on UO-14 since it was
 IC> switched to the service as a FM repeater. This shows that FM birds are
 IC> just as good to attract new operators to the satellite service as the
 IC> mode-A birds. I would like to thank the people who made this
 IC> possible.

These days, I'd say that the FM birds would attract more people, but from the
larger countries.  I've had the opportunity to QSO with people from the small
islands to the east of Australia, and the general consensus is that people
there have 2 metres, but not 70cm, making the existing crop of FM satellites
rather useless for them.  It's quite understandable them not having 70cm, as
these places are so small and far apart that it's not warranted for terrestrial
use. Makes it a bit of a Catch 22 when you're trying to get people interested
in the birds.

That gave rise to a somewhat crazy idea...  Why not a bird with a 2m FM uplink
and a 10m SSB downlink?  Conbine some of the characteristics of the existing FM
birds with the most likely modes that amateurs in smaller countries might have.
Alternatively, a Mode A FM bird, but with narrow FM on the 10m downlink, to
minimise spectrum wastage.

Just thinking out loud, and I digress....

 IC> In Russia the conditions are just as bad. Not only is the 2 meter
 IC> satellite segment used for telephone trafic - but in some cases also
 IC> used by broadcast stations. This is mostly on UO-14.
 IC>
 IC> Some countries in the Middle East also use our frequencies for both
 IC> telephone trafic and broadcast.
 IC>
 IC> The last three examples are in violation with the international rules.

This sounds a bit like the S.E. Asian situation.  I've heard what sounds like
telephone traffic on UO-14, once the footprint comes up over Indonesia, and
some of those signals are very strong.  Basically, UO-14 is unusable within a
minute after the first Asian stations are heard.

More recently, a very serious form of QRM has occurred.  It comes up on UO-14
on a pass which is directly overhead Melbourne, and starts suddenly at or just
before TCA.  It consists of two people talking to each other in a foreign
language.  This signal is extremely strong and makes the bird useless.

>From the early onset, it is too far south to be of Asian origin, so it's either
a small island, ot it's coming from somewhere in Australia itself (can VKs
using UO-14 on passes around 1300z please monitor their uplinks for signs of
this QRM?).  This one is particularly problematic and requires tens of watts
into a small beam (50W+ EIRP) to make a significant dent in.  2W EIRP doesn't
even heterodyne against it. :-(

 IC> A third type of problem is that some high power stations try to
 IC> monopolise the FM satellites. If everybody tried to work one or two
 IC> stations only on each pass, it would be much better.

This is a matter of sharing, and perhaps peer group pressure is the only answer
here.  Shun those using excessive power and squashing the little stations.
Similarly, keep a keen ear out for QRP stations, and as long as the QRP call in
the breaks, keep the frequency clear and give them a go.  It'll make their day
(and should give you a warm fuzzy feeling :) ).

 IC> I have no intention to be a policeman on the satellites - but I would
 IC> like to see the satellites used to forward our hobby in a positive
 IC> way. Please receive this message in the way intended and do something
 IC> about it, if you are in a position to do so.

Agreed.  I tend to be fairly tolerant, but when someone repeatedly does
something disruptive (e.g. call over the top of people when they can obviously
hear them, pass after pass), I might say something.  The people who can't hear
their downlink may get a friendly email and a few pointers for improving their
receive setup.

Tony

.. odems!
--
|Fidonet:  Tony Langdon 3:633/284.18
|Internet: tlang@freeway.apana.org.au
|
| Standard disclaimer: The views of this user are strictly his own.


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