May 2008 - AMSAT-BB - mailman.amsat.org

Re: TrakBox
by Jack E. Davis 06 May '08

06 May '08

At 06:04 PM 5/5/2008, you wrote: >hello all > >my 'old' trakbox (dusty!) ,after 5 years of sleep, doesnt work in >stand alone mode anymore ; terminal mode works perfectly. Ram has been >cleared , clock adjusted, new keplers loaded ; version is 3.50b. > >Any ideas ? > >73 > >renauld on4kvi The first thing I would suggest is to change to 3.50d. TAPR has ROMs and the image is readily available if you can program EPROMs. Also check the battery to see if is still alive. If you need parts let me know as I still have most everything in the kits. After making these changes let me know your results. 73, Jack - WA4EJR

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TLE lottery
by Jeroen Vreeken 06 May '08

06 May '08

Hi, For the last few days I used object H (#32790) for tracking Delfi-C3. It is also the current object mentioned on the delfi-c3 website. However the last few passes it seems that it is getting increasingly late. Object J (#32791) seems to fit much better.... Is anybody else seeing the same? 73, Jeroen PE1RXQ

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AO-51 L/S
by n1jez＠burlingtontelecom.net 06 May '08

06 May '08

Got on AO-51 L/S tonight at 2306 UTC for the first time in a _long_ time. Had the pleasure of working Clare, VE3NPC. Other than that, very quiet. Maybe more folks will be around for the next pass?? 73, Mike N1JEZ AMSAT #29649 "A closed mouth gathers no feet"

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Cubesat Antenna Modeling and truth?
by Robert Bruninga 05 May '08

05 May '08

A big problem on small satellites (cubesats) is how to match antennas. Simply connecting a network analyzer, or MFJ antenna analizer or any other test equpment won't work. Connecting a cable to the satelltie model will completely upset the near-field and any useful measurements. Especiallly, trying to match a 2 meter antenna to a 4" cubesat! I wonder if the best way is to simply do the best you can with EZNEC or other modeling tool, then build a true fidelity model spaceframe with the fully designed and implemented mathcing network, but reserve one side of the model to have a field-strength meter on it connected internally to the actual TX/RX cable to the antenna. Then using long insulated dielectric "tweakers" just tune the matching circuit for max. (Of coures getting out of the way after each tweak).. Also, then comparing the results with a similar field strength meter and tuned dipole as a reference at the same distance. We tried lots of methods, including building in a directional coupler and having it report its reflected power via telemetery... but I think the one above is what I will do next time. When the spacecraft is small, relative to a quarter wave, everything near the spacecraft and any wires/cables have drastic impact.. Has anyone had other successes? Just thinking what we should be telling these students that are building cubesats. A 6" whip for 70cm is not too bad on a 4" cubesat, but 2m is compltely different... Bob, WB4APR

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Re: AO-16 currently silent and resting 11:15UTC 5May2008
by George Henry 05 May '08

05 May '08

Any chance that it will be available for use for the Scout-O-Rama Special Event station (K9BSA) this Saturday, 5/10? George, KA3HSW -----Original Message----- >From: "Mark L. Hammond" <n8mh(a)embarqmail.com> >Sent: May 5, 2008 6:33 AM >To: amsat-bb(a)amsat.org >Subject: [amsat-bb] AO-16 currently silent and resting 11:15UTC 5May2008 > >Hello all, > >The weekend presented a chance to gather some telemetry on AO-16. The telemetry looks nominal. Recently, the satellite seems to go silent on a nearly daily basis. Increasing eclipse periods remain a likely explanation, but we remain open to other explanations at this point. > >To this end, I have turned AO-16 OFF for a few days to rest and ensure that its batteries will be given a chance to become fully charged. Following its several day rest period, we'll try to conduct more tests to better determine what type of operations that AO-16 is currently able to support. > >Please do not transmit to AO-16 until further notice. > >73 on behalf of the command team (and Happy Cinco de Mayo!), > >Mark L. Hammond [N8MH]

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Creating Artworks based on Delfi-C3... or ?
by Henk, PA3GUO 05 May '08

05 May '08

Dear all, Previous days it was observed already, then in periods of maximum signal strengths on LHCP, there is a minimum on RCHP (and visa versa). Triggered by that I wanted to try something else: simulations reception of the two antennas of my 'X' antenna (2x6 elements DK7ZB), and plot the signal strengths over time. Most likely this can be considered as a totally useless experiment, but I wanted to do this for once (could have taken another satellite as well). Both antennas are only 6 cm distance from eachother, which is compensated by a bit of extra coax cable. The two cables enter the shack. One cable has been connected to an FT817. Other cable was connected to an TS2000. Using this set-up I did a simulatious reception of Delfi C3, and plotted the received signals above eachother: Result: Maximum on one antenna is minimum on the other, and visa versa. Have a look yourself at the graph: http://home.vianetworks.nl/users/hamoen/pa3guo/dc3_04may08_2000utc_pa3guo_p… Conclusion of PA3GUO: fun to do, but I have no clue what this tells us :-) Conclusion of PE1ITR: it's beautiful, but one does not know what one can do with it... it's ART ! :-) ... still: - if Delfi C3 has circular polarization, shouldn't both signals have been the same ? - how does this relate to the LCHP/RCHP opposite maximums (see text above) ? Looking forward for your thoughts ! 73, Henk, PA3GUO http://www.qsl.net/pa3guo

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Cute-1.7+APD and Compass-1 over West Malaysia
by Sion Chow Q. C. (9W2QC) 05 May '08

05 May '08

Dear All, Cute-1.7+APD and Compass-1 over West Malaysia. Time: 2305 Local or 1505 UTC Max Elevation: 33 degrees Tracking: Object C http://www.9w2qc.net/amsatbb/cute05may2305.mp3 To the SEEDS team, I attempted to listen to the earlier pass, and SEEDS was in FM digi talker mode. Did not listen to SEEDS during the above pass though. Since the message is the same, I decided to set the station to record in USB mode unattended in case CW telemetry comes on instead. This will be my last report to the AMSAT-BB to reduce bandwidth. All future reports will only be sent directly to the respective satellite teams except for some interesting findings. 73, Sion Chow Q. C., 9W2QC.

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AO-51 LS Mode
by Rm2642＠aol.com 05 May '08

05 May '08

Did not hear anybody on AO-51 LS mode this morning pass 5 May 1512Z. Could be I have a weak setup? Using M2 yagi 23CM35EZ uplink (9 watts out) and 14 turn helix on downlink with 2400-144 downconverter. SatPC32 Doppler.SQF file set at AO-51,2401200.0,1268700,FM,FM,NOR,2256000.0,0. Downlink offset frequency seems okay as shown on my Yaesu FT-736R. Ron n6paa **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001)

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FCAL alive May, 05
by Edward Chuang 05 May '08

05 May '08

Hello, FCAL packet copied at May,05 14:01 UTC over PL04vq: 14:01 KD4HBO/TELEM>TELEM>UI,C,F0: 02960593FFFE00B8FFFFFFE8FFFE0090FFFEFFE0FFFE0048FFFEFE40 14:01 KD4HBO/TELEM>TELEM>UI,C,F0: Analog 0004000100F800DA00A700FE00DF0010 N 0000001E 73 Edward / BX1AD -----

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UT1FG/mm report
by Robert Turlington 05 May '08

05 May '08

Worked Yuri UT1FG/mm on VO52 15mins ago when he was in GM94 mid atlantic this may well be the last time I am able to contact him but will try again tomorrowRegards Robert G8ATE in Io92JP _________________________________________________________________ All new Live Search at Live.com http://clk.atdmt.com/UKM/go/msnnkmgl0010000006ukm/direct/01/

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