Satgen 46  JAS1-B digital, Pacsats, S Band , Listeners.   14 Feb 90.

The Pacsat scene has been very busy this last week. JAS1-B launched  
on 7th Feb 90 was soon providing both analog morse beacons/telemetry,
on 435.795, and analog transponder operation 145.9 to 145.99 up, and
435.9 to 435.8 MHz down. Then last weekend Jamsat switched on the digital
beacon on 435.910 1200bps BPSK down. All these signals were on at the same
time. Access to the analog transponder is very easy, and several European
stations (including some Gs ) are putting in signals 12 to 18 dBs above
the beacon level.With JAS1-B up near 1300 kms high some passes can last
for up to 22 minutes,and even Polar orbits are 9 degs or more above the
Northern UK horizon.

There are also some odd features. The JAS1-B beacon can also be heard near
435.840 and 435.890 MHz. Just why is not clear. Even more confusing as
several stations noticed on Day 1. Shortly after a genuine JAS1-B pass , a
second satellite appeared on 435.795 MHz sending almost exactly the same
telemetry. The culprit appears to be JAS1-A. Did it come alive again in
answer to command signals intended for 1-B, as GM4JJJ suggested, or is it
doing an RS1. Reappearing from time to time , unbidden ? It is noticeable
that 1-A goes on and off, at 1 or 2 minute intervals. So it sounds as if
its behaviour is irregular.

Lusat has been handed over to Amsat Argentina . Pacsat telemetry
originally said its S Band beacon was ON. But now it is saying " S Band
will be inactive until new power routine is uploaded on 14 Feb". Webersat 
is sending weird packets typically labelled "PHOTO 2". Its transmission
has a curious background echo and it is hard to print even when S9. These
video packets will drive your printer crazy if you try to get hard copy.

For Listeners. Dove is receivable on a simple aerial attached to a 145.825
MHz FM Rx, feeding a simple terrestrial Terminal node controller. Pacsat ,
Lusat and JAS1-B are also begining to be copied on very simple equipment.
GM4JJJ used an indoor hand held 10 ele yagi ( back half of a Tonna 19 ele)
70cm aerial coupled direct to a Microwave modules transverter to read
JAS1-B. Then with the same aerial attached to a 437 MHz moded Jamsat
converter he copied Lusat and Pacsat via his DIY G3RUH Fuji modem , TNC
320 fed from his TS 430S Rx.

Now the Pacsats are separating quite quickly I am finalising software to
track any or all of the group at once. This is rather like the old ZX81
program  Russian Convoy which tracked all the RS3 to 8 birds. Only nasty
problem at the moment is the TNC 320 which has data flow problems and is
useless for the packets I want to put up to the Pacsats when they open for
business. Siskin were definitely told about this months ago and this
report has been repeated several times since . I hear something may at
last be happening about this. I hope this is true.73 de John GM4IHJ@GB7MAC