Satgen 161   Amsats QRM . Geosat Information    by GM4IHJ     25 April 92

My thanks to all those of you who sent comments on the satellite
interference. Except that is, the unmentioable who sent me an order via
someone else telling me to stop discussing the subject. Frankly the
subject needs reporting loudly. The silence from RSGB is deafening, and I
do not believe we are , presently, getting anywhere .
Put simply. Since 1982 Radio Amateurs have invested several million pounds
in satellites which are controlled by signals uplinked in the frequency
band 435 to 437 MHz ( Oscar 10, Oscar 13 and RM-1 are most seriously
affected) When these satellites were launched the earlier versions of the
radars which are alleged to be the cause of our present troubles, used
frequencies well below 435 MHz.
Recently for some as yet totally unexplained reason. The latest model of
these radars has abandoned 420 - 430 MHZ and appeared right on top of the
Amateur satellite uplink and control band. Whether this is the result of
ignorance, or, is deliberate, is not clear. Yes the radars do have
priority BUT WHY MUST THEY PICK PRECISELY THAT PART OF THE BAND WHERE THEY
WILL CAUSE MAXIMUM DISTURBANCE TO EXISTING USERS.
Perhaps the radar operators are unaware that modern satellites need almost
constant uplink of command and control data. What used to be a complex but
straight forward task for skilled operators ,is becoming a nightmare as
command stations report that they need ten or more repeats of
transmissions of complex data simply to get one order to the satellite to
keep it in good shape. Accessing the satellites with large blocks of new
software is almost impossible.
Please do not quote "Defence of the Realm " at me. I spent 35 years in HM
Armed Services and I am aware how far removed from reality Defence Dept
officials can be. We need to get across to lots of people in government
that, from the point of view of radio amateurs , we are simply being
trampled undefoot by what appear to be mindless blimps.
We are not millionaires. Amateur Radio simply cannot afford to locate
elsewhere. If the Goverment decide we must accept radars at 435, then they
must be told that it will cost at least 8 million to replace those
satellites suffering gross interference, and, we will also require
reimbursement for facilities lost whilst we are building replacements.

GEOSAT REPORTS. Amsat NA assisted by Uo5 gateways seem to be distributing
a bulletin about which I have had several queries. The bull quotes Hughes
Galaxy 1 sending educational material on Chan 1 5.7975 GHz. 
Am I wrong I thought 5 Ghz was the uplink , and worse still Galaxy 1 last
reported at 134 West is hardly in range of Europe. Is this a new sat, have
US stations started using 5 GHz downlinks, surely no geosat service can be
described as global ? Anyone able to explain this mixed up bulletin ,
please let me know. 73 de John GM4IHJ @ GB7SAN