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SB SAT @ AMSAT $ANS-184.01
AMSAT JOURNAL NEEDS FD PHOTOS
HR AMSAT NEWS SERVICE BULLETIN 170.01 FROM AMSAT HQ
SILVER SPRING, MD JUNE 19, 1993
TO ALL RADIO AMATEURS BT
BID: $ANS-184.01
WA0PTV Would Like Photos Of Your FD Satellite Station For The AMSAT Journal
If you operated a satellite station in conjunction with Field Day, please
don't forget to send your entry in for the AMSAT contest. But please don't
stop there. WA0PTV would like to put a page of photos of representative
satellite Field Day stations in an upcoming the AMSAT Journal and would
also like to publish a short section of comments by those who participated.
WA0PTV would greatly appreciate if you happened to take any photos of your
FD setup to send him a copy of whatever you have available. High contrast
photos will appear best in print, but please send in whatever you have.
Also, please send in any comments or observations you had about this year's
FD exercise. Your comments can also be sent to him via INTERNET at his
address of wa0ptv@amsat.org if you wish. However, photos will need to be
mailed. WA0PTV's postal address is as follows:
John Hansen (WA0PTV)
49 Maple Avenue
Fredonia, NY 14063
Here's a chance for your FD group to receive the world wide coverage it
deserves. The ARRL receives so many photos that the odds of your's showing
up in QST are very remote, but your odds of making the AMSAT Journal are
much greater.
/EX
SB SAT @ AMSAT $ANS-184.02
NEW AO-13 ZRO LEVEL BROKEN
HR AMSAT NEWS SERVICE BULLETIN 170.02 FROM AMSAT HQ
SILVER SPRING, MD JULY 2, 1993
TO ALL RADIO AMATEURS BT
BID: $ANS-184.02
With Digital Signal Processing (DSP) A New ZRO Test Record Has Been Broken
Darrel Emerson (AA7FV) has received confirmation as to being the first
station to successfully receive the ZRO Level "A" code blocks. Most AO-13
operators are familiar with the ZRO tests which occur a few times per year.
These tests assist in determining station receive sensitivity by sending
CW blocks in 9 increments, beginning with signal strength equivalent to
the AO-13 beacon (ZRO Level 0), and decreasing in 3 dB steps down to Level
9, which is 27 dB below the beacon signal strength. AA7FV was part of an
experiment undertaken by Andy MacAllister (WA5ZIB) to see whether a signal
at 30 dB below beacon strength (Level A) could be copied. After consider-
able digital analysis of the recorded signal, AA7FV successfully determined
the content of the code blocks and received confirmation of his copy from
WA5ZIB.
The equipment used at AA7FV to receive the Mode-B ZRO signals is a slightly
worse than the average AO-13 station. The antenna is a 10x10 element
circularly polarized yagi, with 30 ft of RG-8 feeder to an ARR preamp in
the shack. The 2M receiver is a transverter feeding an FT-102 HF trans-
ceiver and using a 250 Hz bandwidth CW filter. Data from the AO-13 ZRO
tests were digitized using a cloned Soundblaster card, giving 4000 8-bit
samples per second, which were analyzed off-line after the test. The data
processing used software written in FORTRAN specifically for the ZRO tests,
running mainly on a 386 PC. A variety of DSP algorithms were used, taking
many hours of computing time -- this is not real-time processing! In this
test, without the software processing, the ZRO signal could barely be
copied by ear through the CW filter at Level 7. The software processing
gives about a 10 dB improvement in S/N over the human ear alone, enabling
accurate copy of the ZRO level "A" data.
The next project for AA7FV is to try to make the software more user
friendly, and to run in real time. There are obvious applications to EME
reception.
WA5ZIB notes that by no means must the ZRO test be done in real time. With
the proliferation of DSP technology and access to fast computers, the
methods for analyzing the ZRO test signals are as unlimited as the user's
imagination and any method of extracting the code blocks, eg., using
superDSP's and a Cray YM-P for software based analysis of the data, is
completely "legal."
[The AMSAT News Service (ANS) would like to thank Dave Burnett (WD8KRV)
for this bulletin item.]
/EX
SB SAT @ AMSAT $ANS-184.03
AMSAT OPS NET SCHEDULE
HR AMSAT NEWS SERVICE BULLETIN 170.03 FROM AMSAT HQ
SILVER SPRING, MD JULY 2, 1993
TO ALL RADIO AMATEURS BT
BID: $ANS-184.03
AMSAT Operations Net Schedule
AMSAT Operations Nets are planned for the following times. Mode-B Nets
are conducted on AO-13 on a downlink frequency of 145.950 MHz.
Date UTC Mode Phs NCS Alt NCS
10-Jul-93 1300 B 90 WJ9F VE2LVC
17-Jul-93 1800 B 119 VE2LVC W9ODI
24-Jul-93 1930 B 70 N7NQM W5IU
31-Jul-93 1300 B 98 WB6LLO WA5ZIB
Any stations with information on current events would be most welcomed.
Also, those interested in discussing technical issues or who have questions
about any particular aspect of OSCAR statellite operations are encouraged
to join the OPS Nets. In the unlikely event that either the Net Control
Station (NCS) or the alternate do not call on frequency, any participant is
invited to act as the NCS.
**************************************
Slow Scan Television on AO-13
SSTV sessions will be held on immediately after the OPS Nets a downlink on
a Mode-B downlink frequency 145.960 MHz.
/EX
SB SAT @ AMSAT $ANS-184.04
WEEKLY OSCAR STATUS REPORTS
HR AMSAT NEWS SERVICE BULLETIN 170.04 FROM AMSAT HQ
SILVER SPRING, MD JULY 2, 1993
TO ALL RADIO AMATEURS BT
BID: $ANS-184.04
Weekly OSCAR Status Reports: 03-JUL-93
AO-13: Current Transponder Operating Schedule:
L QST *** AO-13 TRANSPONDER SCHEDULE *** 1993 Jun 27-Jul 10
Mode-B : MA 0 to MA 20 !
Mode-S : MA 20 to MA 30 !<- S transponder; B trsp. is OFF
Mode-B : MA 30 to MA 256 ! Attitudes:
Mode- : MA ! Jul 03 135/0
Mode- : MA ! Jul 10 140/0
Omnis : MA 170 to MA 10 ! Jul 17 145/0
Please don't uplink to Mode-B during MA 20-30 because it will interfere
with Mode-S operations. [G3RUH/DB2OS/VK5AGR]
MIR: A Soyuz TM-17 blasted off from the Baikonur cosmodrome in Kazakhstan
this past Thursday with two Russians and a Frenchman aboard. The cosmo-
nauts -- Vasily Tsiblyev (R3MIR) and Alexander Srebrov (R4MIR) of Russia
and Jean-Pierre Haignere of France -- will join Gennadi Manakov (U9MIR) and
Alexander Poleshchuk (R2MIR) who both have been aboard MIR for 161 days.
The docking operations which were completed by 16:24 UTC on Thursday and
were broadcasted live by television and also received at the Paris head-
quarters of the French space agency, CNES. After conducting experiments
aboard MIR for 18 days, U9MIR and R2MIR will return to Earth on 22-JUL-93
along with Haignere. R3MIR and R4MIR will remain in the space station
until the end of the year. In other news about MIR operations, UA3CR
reports that the cosmonauts are "sticking" with the standard MIR downlink
frequency of 145.550 FM simplex and will no longer make use 145.850 MHz.
While the cosmonauts had been experimenting for a short time with using
145.850 MHz, they quickly realized they were creating a great deal of QRM
to many OSCAR satellite users on this frequency with their QSOs. There-
fore, they will only use 145.550 MHz only. [LW2DTZ/UA3CR/N1MDZ]
AO-16: Operating normally. [WH6I]
UO-22: Operating normally. [WH6I]
KO-23: Operating normally. [WH6I]
FO-20: The transponder schedule will return to its usual modes of operation
now that Field Day weekend has passed. Wednesdays will be the analog mode
(JA) and the digital mode (JD) will be at all other times. N0NBH reminds
all FO-20 users to PLEASE DISCONNECT BEFORE THE END OF THE PASS! He says
that you should always make a "clean" disconnect before FO-20 travels over
the horizon from your QTH. If you fail to disconnect, the FO-20 BBS will
perform the disconnect itself after about 15 minutes of no activity from
your station. However, during this time the BBS will not let anyone else
log in until the disconnect has been performed. Thus, you will be limiting
FO-20's operational capabilities for all users. Please remember to dis-
connect before LOS. [N0NBH]
AO-21: KD8PH notes that AO-21 is quite busy on the early morning passes.
He also notes that when AO-21 does becomes highly congested there is no
"gentlmanly" protocol agreed upon by AO-21 users to handle this problem.
If you have suggestions about how such a protocol should be implemented,
please send them KD8PH @ N9AZZ so that they can be discussed and published
in the AMSAT News Service (ANS) bulletins. The resulting lack of a pro-
tocol on AO-21 is causing a reduction in operating pleasure for all users
of AO-21. [KD8PH]
The AMSAT NEWS Service (ANS) is looking for volunteers to contribute weekly
OSCAR status reports. If you have a favorite OSCAR which you work on a
regular basis and would like to contribute to this bulletin, please send
your observations to WD0HHU at his CompuServe address of 70524,2272, on
INTERNET at wd0hhu@amsat.org, or to his local packet BBS in the Denver, CO
area, WD0HHU @ W0LJF.#NECO.CO.USA.NOAM. Also, if you find that the current
set of orbital elements are not generating the correct AOS/LOS times at
your QTH, PLEASE INCLUDE THAT INFORMATION AS WELL. The information you
provide will be of value to all OSCAR enthusiasts.
/EX