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

CubeSats new TLE
by Mineo Wakita 07 May '08

07 May '08

In NORAD: 32783 OBJECT A = CARTSAT-2A 32784 OBJECT B = CANX-6 32785 OBJECT C = CANX-2 32786 OBJECT D = IMS-1 32787 OBJECT E = COMPASS-1 32788 OBJECT F = AAUSAT-II 32789 OBJECT G = CUTE-1.7+APDII 32790 OBJECT H = DELFI-C3 32791 OBJECT J = SEEDSII 32792 OBJECT K = RUBIN 8/PSLV

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Delfi C-3 not so strong
by Paulo Pinto 07 May '08

07 May '08

Hi, For the last two days I noticed that signals from Delfi-C3 over Europe are not so strong as they were in the first 6 days. I have the same antenna setup which consists of a 9 element Yagui on my balcony (no rotor and abt 10 deg North/ 10 deg Elev.) and TS-2000. Anyone noticed that? 73's Paulo, CT1ETE

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DELFI C 3
by Luc Leblanc 07 May '08

07 May '08

I watched DELFI C 3 when he goes out eclipse. As soon as he get some light he start to transmit his data but and as reported by some listeners he stopped transmitting after one or two minutes and he normally does not come back even if he's in full light. My question: is it normal or is it a problem? Thank's for your inputs P.S. SEEDS is now in CW TLM mode i try to decoded with CWGET but he's not reliable i will have to recorded and decoded it after...Pain in the neck as my CW is a "bit" rusty Did any one try another CW decoder who at least put gaps between TLM strings? Too lazy to copy CW "-" Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE

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C3 heard 6-5-2008 at 8:00 and 18:55 utc
by Kostas Ioannidis 07 May '08

07 May '08

C3 heard 6-5-2008 at 8:00 and 18:55 utc at 145.930Mhz sending tlm. Packets uploaded to the server. 73 de sw1ixp

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Re: Cubesat Antenna Modeling and truth?
by Anthony Monteiro 07 May '08

07 May '08

At 12:12 PM 5/4/2008, Robert Bruninga wrote: >A big problem on small satellites (cubesats) is how to match >antennas... >... >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... Hi Bob, This problem is not new. Walt Maxwell, W2DU had the same problem when working on antenna for big satellites at RCA Astro-Electronics. His solution was to use ferrites to decouple the feed cable from the satellite body. Then you can just use a directional coupler outside the satellite to measure the return loss. I have used this and it works pretty well as long as you keep the feed cables at 90 degrees from the antenna E field. You can use the EZNEC model to determine the expected E-field. You need to make sure the ferrites provide at least 10x the impedance of the antenna at the satellite (i.e. if you expect 35 ohms for the antenna, you need at least 350 ohms from the ferrites.) Also, you MAY need to break up any resonances on the cable by putting ferrites every 1/8 wavelength on the feed cable if you cannot get the cable at a true 90 degrees. Note that 90 degrees will not likely be directly broadside from the satellite especially for a 4" cube on 2 meters. 73, Tony AA2TX

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Getting RASCAL into SYNC
by john heath 07 May '08

07 May '08

Hi, Thanks for the tip on this bb to use something like Spectran to tune the radio so that the strongest part of the signal is on 1600 Hz. Here is an useful observation - constant manual frequency adjustments of the radio seem to defeat the Costas Loop ? and prevent the software from locking onto the signal. Get close to 1600 then wait a few seconds to allow the software to do its job. Lost sync a few times due to deep QSB but got 172 packets on the afternoon pass at IO92IO. I am sure this is by no means a record but its a lot better than I have managerd so far. Hope this helps. 73 John G7HIA

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Re: TLE lottery
by Mike Rupprecht 06 May '08

06 May '08

Hi, I agree Colin, Compass appearing before Cute but we work with 32787 (E) and 32785 for Cute (C) with good results. 73, Mike DK3WN Betreff: [amsat-bb] Re: TLE lottery Gesendet: Di, 06. Mai 2008 Von: Colin Hurst<cjhurst(a)bigpond.net.au> > Jeroen, > I do agree with your observations. > My observations have Compass appearing before Cute1.7+APDII. > I would suggest Compass is H and Delfi-C3 is J. > But time will tell. > Colin VK5HI. > > > > -----Original Message----- > > From: amsat-bb-bounces(a)amsat.org [mailto:amsat-bb-bounces@amsat.org]On > > Behalf Of Jeroen Vreeken > > Sent: Tuesday, 6 May 2008 8:32 AM > > To: amsat-bb(a)amsat.org > > Subject: [amsat-bb] TLE lottery > > > > > > 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 > > > > _______________________________________________ > > Sent via AMSAT-BB(a)amsat.org. Opinions expressed are those of the author. > > Not an AMSAT-NA member? Join now to support the amateur > > satellite program! > > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > _______________________________________________ > Sent via AMSAT-BB(a)amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > --- original Nachricht Ende ----

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Re: DELFI decoded
by Mark L. Hammond 06 May '08

06 May '08

Hi Bruce, On my TS-2000x I find setting the LOW cut off around 200 Hz (or maybe 100 Hz) and the HI cutoff around 2600 (or maybe 2400) works pretty well on 1200 BPSK signals like Delfi-C3. Give that a try... you can go a bit wider (100/2600), or a bit more narrow (200/2400)..but 200/2600 should be pretty good. 73, Mark N8MH Date: Tue, 6 May 2008 12:04:48 -0300 From: "Bruce Robertson" <ve9qrp(a)gmail.com> Subject: [amsat-bb] Re: DELFI decoded To: "Viktor Kudielka" <viktor.kudielka(a)ieee.org> Cc: AMSAT <amsat-bb(a)amsat.org> Message-ID: <49657a760805060804xcf5383ah2810ae488bff1db9(a)mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 It is possible to tune for RASCAL by ear. I use the following steps: 1. Tune to find the frequency with the greatest s-meter reading 2. Listen to the tone part of the signal, not the raspy part, and aim for a note much higher than a regular CW signal. 3. When the green sync light goes on in RASCAL, fine-tune to centre the signal at 1600 Hz. Does anyone know how narrow a SSB filter I can apply to this signal? I have a TS-2000, which is quite adjustable. For now I'm using it wide open. I know the centre signal is 1600 Hz, which is quite high. How high/low do the sidebands go?

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SEEDS, Cute-1.7+APDII and COMPASS-1 over West Malaysia
by Sion Chow Q. C. (9W2QC) 06 May '08

06 May '08

Dear All, Pass report for SEEDS, Cute-1.7+APDII and COMPASS-1 over West Malaysia Time: 1054 Local or 0254 UTC Max Elevation: 55 degrees Satellites: Cute-1.7+APDII & COMPASS-1 http://www.9w2qc.net/amsatbb/cute05may1054.mp3 After 3 minutes, QSYed to SEEDS which was in digitalker mode. Below is the best SSTV picture from SEEDS. Can anyone explain why the image is still noisy despite a full quieting 59+10db signal (with preamp on)? http://www.9w2qc.net/amsatbb/seeds05may1054.jpg Also had an earlier 3 degree pass that was copied unattended. This was an exclusive SEEDS pass which was also in digitalker mode. 73, Sion Chow Q. C., 9W2QC.

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Cochise Amateur Radio Assn. hamfest on Saturday (3 May) - report
by Patrick STODDARD (WD9EWK/VA7EWK) 06 May '08

06 May '08

Hi! On Saturday, 3 May 2008, the Cochise Amateur Radio Association (CARA) held its annual Larry Warren Hamfest on its "Green Acres" field in Sierra Vista AZ (grid DM41vm): http://maps.google.com/maps?f=q&hl=en&geocode=&q=31.5197+n+110.1901+w&ie=UT… As part of the hamfest, there was an AMSAT table with information related to amateur satellites and on-air demonstrations during 3 passes. This was a large (for Arizona) effort, with two Sierra Vista hams (Jeff K7WIN, Bill K7WJS) taking the lead with the planning for the effort. Larry W7LB from Tucson and I (driving in from Phoenix) were also part of this. Jeff and Bill have done presentations for the CARA in the recent past, laying the foundation for the AMSAT effort at the hamfest. The CARA even authorized us to use its callsign K7RDG for our radio operations during the hamfest. Jeff and Bill also had information on IRLP and EchoLink, and we monitored K7WIN's 70cm repeater on both of those networks in case anyone wanted to call us during the hamfest. We set up the tables in time for the 7am (1400 UTC) start of the hamfest, put out flyers and AMSAT merchandise, and prepared our stations (satellite and IRLP/EchoLink). We were ready for the first pass, and talking with hams and anyone else walking by until the first satellite pass. AO-51 came by for an overhead pass between 1453 and 1508 UTC, and it was a busy pass. K7RDG made contacts with 2 Canadian stations, 6 Mexican stations, and 8 stations from all over the continental US. Despite the number of stations, this was a very good pass to show those not familiar to satellite operating. About 20 minutes after that pass (1529-1543 UTC), SO-50 went by from the north to the southeast. With a maximum elevation of 51 degrees at our station, it was another good pass for a demonstration. K7RDG logged contacts with 10 different stations during this pass. One Canadian station, 5 Mexican stations, and 4 US stations - again, a very nice show for the audience. Once SO-50 passed by, we had almost an hour before the next pass. AO-51 made a low pass (maximum elevation 8 degrees) to the west between 1633 and 1644 UTC. With mountains in that direction coupled with the low elevation, K7RDG logged only 5 contacts on this pass. Four in the continental US, and one (Dale KL7XJ) in Alaska. As with other Saturday hamfests in Arizona, this hamfest went until midday. Then we, like everyone else, packed up our stuff. Lots of people stopped by our tables, we made 31 contacts with stations from Alaska to central Mexico and all across the US, and everyone had a good time. Thanks to the Cochise Amateur Radio Association for the space and the use of the K7RDG call for our demonstrations, to the operators on these 3 passes (especially the many XE stations that showed up and said "hello" to the hamfest), and to Jeff K7WIN and Bill K7WJS for their work leading up to - and on the day of - the hamfest. 73! Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/

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