September 2006 - AMSAT-BB - mailman.amsat.org

The SSETI ESEO GTO project
by Graham Shirville 20 Sep '06

20 Sep '06

Hi All, Just a quick update about the SSETI GTO satellite project. It is still on track for a launch from Kourou in Nov 2008. The planned AMSAT-UK U/S linear transponder is still on the manifest. (We do not have any opportunity to change from this frequency selection) The transponder is expected to have: an approx 50kHz bandwidth 10 watts of RF output Selectable DSP/SDX and analogue signal paths a 400bps beacon linear antennas with not much more than zero gain The satellite may not have good, long term, attitude control therefore: the antennas are being designed to work well even if the satellite is tumbling the link budget is not as good as AO40 was nor as P3E will be:( circular polarisation of ground segment antennas will be needed. Before we operate the system as an amateur transponder, it will be used as the initial main communications package for the reception of telecommands to, and for the transmission of telemetry and mission data from, the satellite - so it is quite important for the whole project:) The Preliminary Design Review will be completed during next month and an engineering model of the satellite should be under construction early next year. Hopefully this process will be visible using the same webcam system as we were able to engineer during the SSETI Express construction. The website http://www.sseti.net/ has lots of info about the SSETI program(me). Click on "missions" and ESEO for more details about their plans for their GTO satellite. A full report on the SSETI Express launch last year, the SSETI ESEO project with the DSP transponder, and their SSETI ESMO (moon orbiter!) project will be provided at the upcoming AMSAT-NA Symposium. 73 Graham G3VZV

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Re: Why do the amsats get more and more complex?
by John B. Stephensen 20 Sep '06

20 Sep '06

We lost 1215-1240 MHz to GPS and were required to accept interference from ISM devices on 2400-2450 MHz 25 years ago so further restrictions are possible in the future. 73, John KD6OZH ----- Original Message ----- From: <sco(a)sco-inc.com> To: <amsat-bb(a)amsat.org> Sent: Wednesday, September 20, 2006 18:30 UTC Subject: [amsat-bb] Re: Why do the amsats get more and more complex? Looks to me that only the commercial service will possibly interfere with the Ham L band uplink. The open service signals will not be in the L band. Even then the Commercial service will be broadcast in three bands, only one of those is in our ham band. I would therefore assume if the commercial receiver was having interference on the CS channel (our L band) that it would switch over to one of the other TWO Open channels to gets its info. See the specs below. So what is the problem. Are we afraid that we might offend the Europeans if we are on one of their three channels? Sounds to me like Europe is building this system so they will have their own GPS if they decide to go to war with us. I hope they build it such that the Islamic Fascists can't use it to deliver bombs and missiles. Les W4SCO At 02:05 PM 9/20/2006, John B. Stephensen wrote: >Unfortunately, the Gaileo downlink covers >1258-1299 MHz, the first satellite has been >lanched and the satellites in the constellation >will be on over the entire world. Our uplink >antennas have sidelobes that are 10-20 dB down, >so a 1 kW EIRP SSB uplink results in 10-100 W >radiated towards terrestrial receivers. A 256 >kbps uplink would require 16 kW EIRP and be 0.5-1 MHz wide. > >P3E has a second L receiver tuned to a null in >the Galileo signal (there is only one null in >the 1260-1270 MHz band) but no one knows if this >will help. SSB users can move to the U uplink if >L is a problem. However, this only works for >narrowband signals. A wideband uplink won't fit >in the null and can't move down in frequency. > >73, > >John >KD6OZH There will be four different navigation services available: * The Open Service (OS) will be free for anyone to access. The OS signals will be broadcast in two bands, at 1164-1214 <http://en.wikipedia.org/wiki/MHz>MHz and at 1563-1591 MHz. Receivers will achieve an accuracy of <4 m horizontally and <8 m vertically if they use both OS bands. Receivers that use only a single band will still achieve <15 m horizontally and <35 m vertically, comparable to what the civilian GPS C/A service provides today. It is expected that most future mass market receivers, such as <http://en.wikipedia.org/wiki/Automotive_navigation_system>automotive navigation systems, will process both the GPS C/A and the Galileo OS signals, for maximum coverage. * The encrypted Commercial Service (CS) will be available for a fee and will offer an accuracy of better than 1 m. The CS can also be complemented by ground stations to bring the accuracy down to less than 10 cm. This signal will be broadcast in three frequency bands, the two used for the OS signals, as well as at 1260-1300 MHz. * The encrypted Public Regulated Service (PRS) and Safety of Life Service (SoL) will both provide an accuracy comparable to the Open Service. Their main aim is robustness against jamming and the reliable detection of problems within 10 seconds. They will be targeted at security authorities (police, military, etc.) and safety-critical transport applications (air-traffic control, automated aircraft landing, etc.), respectively. In addition, the Galileo satellites will be able to detect and report signals from COSPAS-SARSAT search-and-rescue <http://en.wikipedia.org/wiki/Emergency_Position-Indicating_Radio_Beacon>beacons in the 406.0-406.1 MHz band, which makes them a part of the <http://en.wikipedia.org/wiki/Global_Maritime_Distress_Safety_System>Global Maritime Distress Safety System. >----- Original Message ----- From: <sco(a)sco-inc.com> >To: <amsat-bb(a)amsat.org> >Sent: Wednesday, September 20, 2006 16:16 UTC >Subject: [amsat-bb] Re: Why do the amsats get more and more complex? > > >> >>Galileo (if it is ever built and launched and worked) would just be >>over Europe, right? That would leave the rest of the world the >>ability to use our L band uplink, right? If we hams are using a dish >>pointed at the sky with a narrow bandwidth how is that going to >>interfere with ground receivers some distance from us? We would be >>smart enough to not have the Eagle uplink on the same freq, right? >>And we would design Eagle such that we could (from ground control) >>move the Eagle receive freq away from any potential conflict with >>Galileo, right? And Eagle would be in orbit and operational long >>before Galileo, right? And Galileo receivers on the ground will have >>the ability to cut out any possible interference from us, right? >> >>Seems to me that we are planning to give up the L band (as an uplink) >>based on a lot of bad assumptions. >> >>Les W4SCO >> >> >>>The answer is in two parts. First, an L-band ground antenna would be too >>>large to disguise as a TVRO dish. Second, there is fear that over the >>>lifetime of Eagle that L-band could become unavailable, particularly in >>>Europe, if the Galileo system is deployed. Galileo would be a primary >>>service and Ham transmissions would likely interfere with low cost >>>commercial receivers. >>> >>>I don't wish to debate these points. I'm just telling you the reasoning >>>that >>>went into not choosing L-band. I assure you that every possibility was >>>considered. Lists were created and discussed on each alternative. >>> >>>Rick >>>W2GPS >>>AMSAT LM2232 >> >> >> >>_______________________________________________ >>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

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Mode B equipment for eagle (fwd)
by McGrane 20 Sep '06

20 Sep '06

Greetings- considering the recent discussion regarding Eagle modes, I thought I would repost this question for any answers. Will I be able to use traditional SSB gear for Eagle mode B? I have recently combined an Azimuth rotator and a cheap TV rotator for elevation adjustments using short beams but can upgrade the antennas later. Thanks in advance for any replies, pat n2oeq ---------- Forwarded message ---------- Date: Sat, 9 Sep 2006 07:46:45 -0400 (EDT) From: McGrane <tmcgrane(a)suffolk.lib.ny.us> To: Amsat BB <amsat-bb(a)amsat.org> Subject: Mode B equipment for eagle Greetings In the past couple of years, I have set up a very cheap satellite station for mode B. I had a 2 meter all-mode mobile rig (FT480R) I paid 50 dollars for connected to a cushcraft 4 element Yagi beam. I purchased a 70 centimeter FT790RII for $125 and made a homebrew 8 element Yagi. Antennas are monted on single azimuth rotator mast and angled up about 10 degrees. This setup works extremely well for hamsat (VO-52). Now, going from LEO hamsat to HEO Eagle, I will probably have to make a longer UHF yagi and add an amplifier, Also a longer VHF beam. I already have a mirage 2 meter amp with built in preamp. If the coax is short as it is now, I can use the amp's preamp. I saw a reference in one of the flurry of emails mentioning a 1KW ERP SSB station for eagle. Right now, for UHF, I'm at about 250 watts ERP. Either adding an amp or making a new antenna will bring me up to 1KW ERP or more. Am I on the right path? Will I be able to add to this equipment to work Eagle or will something totally new be required for mode B ? Thanks for ideas, Patrick N2OEQ

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Re: Why do the amsats get more and more complex?
by G0MRF＠aol.com 20 Sep '06

20 Sep '06

In a message dated 9/20/2006 2:29:17 AM GMT Standard Time, w9ae(a)charter.net writes: 3. Eagle plans to have a backup analog transponder path in case the software-defined transponder fails. Hi Wayne. >From several e-mails in the past week it is clear that Eagle WILL NOT have an analog back up. The best we can hope for is a redundant DSP / SDX which means any inherent weakness will cause both to fail. Regards David

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Problem with Wisp (View-Dir)
by N6FO - Jim Cottle 19 Sep '06

19 Sep '06

Hi there, I hope that this newbie issue is not too annoying. I have read the AMSAT digital guide, reinstalled WiSP on my Windows XP computer in the C:\ root directory and have successfully read and requested files from GO-32 (with success). Both GSC and MSPE seem to work as they should. Try as I might however, when I use the program View-Dir, I see NOTHING!. I know the files are there, because I can read them individually (like message files and the MSPE header file for the directory). They are also in their proper directory structures (for AO-51 and GO-32) Anyone out there have a clue as to why View-Dir in my installation cannot actually see the PHF (I think that is the extension) info in the directory file? Makes housekeeping impossible. Any clues or anyone else have this sort of issue that they eventually resolved? Thanks in advance. Feel free to email me directly, or respond here (as appropriate for others). I look forward to learning why View-Dir has such a peculiar issue on my installation. thanks again. 73 Jim N6FO Many thanks to Dave G1OCN for help in navigating some annoying difficulties....THANKS ELMO..;).

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Doppler tuning on older radios
by Lars Petersen 19 Sep '06

19 Sep '06

Hello group, My Kenwood TM-455E (70cm all-mode transceiver) has no RS-232 interface, but it can be controlled in steps of 10 Hz using the microphone's up/down buttons. What software/interface do I need to add automatic doppler tuning? 73, OZ1BXM Lars, Holstebro, Denmark, AMSAT #36222

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OOPS - for N2NHN
by Gene Marks WB2LLP 19 Sep '06

19 Sep '06

John, You had a good signal into AO-51 at 1100 EDST. Several people tried to call you, but apparently you did not hear them. Good luck with your receive problem. 73 de WB2LLP My apologies to N5AFV for a head/finger problem.

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For N5AFV
by Gene Marks WB2LLP 19 Sep '06

19 Sep '06

John, You had a good signal into SO-51 this noon and several people tried to call you. Good luck with your receive problem. 73 de WB2LLP

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Re: SO-50 1900 pass
by John Mock KD6PAG 19 Sep '06

19 Sep '06

> Tried with a handheld with a whip, heard a couple calls but couldn't make > them out. Anyone have success with a like setup? I used to work AO-27 routinely with a long rubber duck, but i cheated a bit. Most often, i'd use a chain link fence (otherwise a large street lamp pole) as a reflector. I'd try to keep the radio about 1/4 of a 2 meter wavelenth from the fence (which 3/4 of a wavelength at 70cm). It made a big difference compared to operating in open space. One time, i worked both Alaska and Hawaii from the parking structure of the Walnut Creek BART station with a long rubber duck and metal fence as a reflector, and i think it was even on low power. This is not a beginner-type thing to do, but with a good path and a good radio, sometimes it can be made to work. Don't do this without a full duplex dual-bander or two radio, as otherwise you are very likely to cause QRM and make sure you can copy callsigns before transmitting!!! ID as QRP, as then folks may also help you out. 73's and good luck. -- KD6PAG (Networking Old-Timer, Satellite QRPer) P.S. SO-50 have been fairly quiet lately and more usage would be appreciated even on transcontinental passes. [Note: If i'm in your address book, please replace 'qsl.net' with 'amsat.org'.]

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Activity from Hawaii
by John W Lee 19 Sep '06

19 Sep '06

Hello All, Ron, W6ZQ, advises me that he and Rick, WH6FC will be active on SO-50 and AO-51 for the next week or two from Hawaii. They are on the big island now, BK28 and BK29. Ron will be going to Maui next week for a week or two, BL10, BL20, BL21. Good hunting ! Check those westerly passes ! 73, John K6YK

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