SB SAT @ AMSAT $ANS-188.01 AO-40 SCHEDULE CHANGE AMSAT News Service Bulletin 188.01 From AMSAT HQ SILVER SPRING, MD. JULY 7, 2002 To All RADIO AMATEURS BID: $ANS-188.01 Effective on orbit (765), on all days except Wednesday, the S2/K-Tx beacon only and passband segments are active again for testing. Note that the beacon only session (no passband) for S2 and K Tx's is MA 116-120, and the beacon + passband session is MA 120-128. As before, on Wednesday, the V-Rx along with L-band Rx's are connected to the passband from MA 120-128. N QST AO-40 S2 Downlink #=Wed, @=non-Wed 2002-06-30 MA 036 120# 116@ 120@ 128 160 200 240 036 ---------1-----4-----2-----6-----3-----5-----7-----0-----1 MB | * | * | S/K | S/K | | * | * | * | RUDAK | | | | | * | | | | V-Rx | | * | * | | * | | | * | U-Rx | * | | | * | | * | * | | Passband | UL | VL | | UL | | UL2 | | | --W4SM for the AO-40 command group. [ANS thanks Stacey W4SM for the above information.] Yoshihiro JF6BCC/KH2GR provided the same data in a revised format: MA 36 116 120 128 160 200 36 ------------+------------+-----+-----+----------+------+--------+ Daily =====S-MB===============><==RUDAK==><=====S-MB======= - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Wed. Only <===UL============><=VL=> <=UL2=> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Exc. Wed. <===UL=======> <=UL=> <=UL2=> <===K-MB===> ----------------------------------------------------------------- /EX SB SAT @ AMSAT $ANS-188.02 PCSAT TEST RESULTS AMSAT News Service Bulletin 188.02 From AMSAT HQ SILVER SPRING, MD. JULY 7, 2002 To All RADIO AMATEURS BID: $ANS-188.02 On Thursday, 27 June a user Load Test was conducted on PCSAT before it goes back into maximum ecllipses. PCsat is still usable in the afternoon sun, but not in the morning or at night due to not being charged up. PCsat is running out of battery power and resetting itself every eclipse. RESULTS: A Qualified success. With a user load of 56 simultaneous users, the success rate was over 97%, thus validating the viability of the PCsat and other Space digipeaters (ISS) as a means of letting a large number of users share a satellite during a pass. DISCUSSION: But it was still not a full load test, since the digipeater was still only lightly loaded (maybe 10% of design load). The design goal of PCsat was to be able to support on average about 300 to 500 users per day in the USA. PCsat was not available during Field Day due to run down batteries. Maybe then we could have seen how the design would have worked with a full load of several hundred users. The following are the details of the test. SUCCESS: 30 out of 31 with the correct settings were successful (97%) LOAD: 16 others were trying (QRM) but had the wrong digipeater callsign because PCsat reset in Eclipse and was not properly configured. Of these, one station reported transmitting every 12 seconds throughtout the pass in frustration. Compared to the requested nominal 2 minute rate, he counts for an added channel load of 10 more users... for a total of 56. The desired transmit duty cycle per user was to be one packet every 1 or 2 minutes. Most users appear to have adhered to that objective and still were able to achieve success. If we make it to the next full sun period in September, maybe we can try again to get a full user load to validate the design. Thanks for all your participation. Bob Bruninga WB4APR These calls were successful: AA3VO,AA9LC,AB7QN K5OE,K9ORP,KA0AZS,KB0VBZ,KB1GUE,KB5HPL,KC0JHQ,KC4ZGQ,KD7MJC N3SOK,N4QWF,N6CO,N6JLH,N7VMR,N9ORP,N8ORJ,NP3ZY W3SMK,W4JBB,W8AAS,WA4SAS,WA4SSP,WB4APR,WB4JBB,WB8NW VE3DOH,XE2ARF [ANS thanks Bob WB4APR for the above information.] /EX SB SAT @ AMSAT $ANS-188.03 THE 7 BILLION MILE UPLINK AMSAT News Service Bulletin 188.03 From AMSAT HQ SILVER SPRING, MD. JULY 7, 2002 To All RADIO AMATEURS BID: $ANS-188.03 How's your uplink today? When controllers made contact with Pioneer 10 at a distance greater than 7.4 billion miles they used the 70 meter dish at Goldstone, California with an uplink transmit power of 200 Kw. The Pioneer 10 spacecraft received the signal at -131.7 dbm after a transit time of about 11 hours. The reply from Pioneer 10 was received back on Earth an addi- tional 11 hours later. The received downlink signal strength from the spacecraft was about -183 dbm. Signal processing algorithms peaked the received signal at -178.5 dbm. Telemetry decoding of the 16 bps data stream was able to be processed at a signal-to-noise ratio of -0.5 db. It was also detected by SETI. So the next time you're thinking of putting off tweaking your antenna system remember you've got lots of work to do! One old timer told ANS, "If your antenna stayed up all winter then it wasn't big enough!" /EX SB SAT @ AMSAT $ANS-181.10 NEWS IN BRIEF FOR THIS WEEK AMSAT News Service Bulletin 181.10 From AMSAT HQ SILVER SPRING, MD. JUNE 30, 2002 To All RADIO AMATEURS BID: $ANS-181.10 ** The launch of Arianespace's eighth mission of the year is on schedule for July 5, when a heavy-lift Ariane 5 is to loft a dual telecommunications satellite payload. --SpaceDaily ** Scientists have found new evidence that light emanating from near a black hole loses energy climbing out of a gravitational well created by the black hole, a key prediction of Einstein's theory of general relativity. --SpaceDaily ** Space Daily covers the resurrection of AO-7 in a story called "Harry Potter and the Magical Satellite". It can be read on-line at: http://www.spacedaily.com/news/amsat-02a.html --SpaceDaily ** The AO-40 telemetry server 147.229.195.185 port 1024 is out of service until July 15. --Mirek OK2AQK ** A Boeing Delta 2 rocket has launched NASA's deep space comet explorer Contour. Contour will spend the next 25 days in orbit ahead of it's deep space trajectory insertion in August. Contour's first comet flyby will be Encke in November 2003. --SpaceDaily With the change in Editors, ANS has made some changes in format. ANS has split the News section from the Satellite Report, for a trial period. Please send your thoughts on this to VE3FRH@amsat.org. Both Sections will be available to all subscribers of ANS. Mike Seguin N1JEZ the Principal satellite Investigator, will continue to supply the satellite information section and all information should be sent directly to N1JEZ@amsat.org. ANS is looking for two more co-editors to take turns in the development of ANS, If you are interested please send an e-mail to VE3FRH@amsat.org [ANS thanks Robin Haighton VE3FRH for the above information] /EX