- Amsat-dc (INACTIVE) - mailman.amsat.org

wanted: to borrow or buy a Yaesu G-5500 AZ-EL controller and rotor
by David Bern 03 Jun '13

03 Jun '13

Friends: I am working on a summer project with students at Montgomery College, Rockville. The project is to design and build a device that controls a pair of inexpensive satellite TV rotors. And the device would emulate a popular AZ-EL rotor such as a Yaesu G-5500 AZ-EL controller so it can be used by a satellite tracking program such as SatPC32. Tom, K3IO suggested this project at the last AMSAT-DC workshop and is guiding us with this project. I would like to borrow a Yaesu G-5500 AZ-EL controller and rotor for about three months or buy a used one so we can study and understand its command protocol. I will pick up or pay for shipping. Please contact David, W2LNX directly at W2LNX(a)amsat.org Thank you, David, W2LNX

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Re: wanted: to borrow or buy a Yaesu G-5500 AZ-EL controller and rotor
by Daniel Schultz 03 Jun '13

03 Jun '13

Only if you have the source code and are able to rewrite and recompile it every time a new operating system comes out. Dan Schultz N8FGV ------ Original Message ------ Received: Sun, 02 Jun 2013 06:53:40 AM EDT From: David Bern <David.Bern(a)engineer.com> To: Louis Mamakos WA3YMH <louie(a)transsys.com>Cc: AMSAT-DC mailing list <amsat-dc(a)amsat.org> Subject: [amsat-dc] Re: wanted: to borrow or buy a Yaesu G-5500 AZ-EL controller and rotor > Correction: I told them that hardware comes and goes but software is > forever. >

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FW: PhoneSats Back on Earth
by Kilroy, Patrick L. (GSFC-5680) 29 Apr '13

29 Apr '13

Game Over. ... See their message below. Did you hear any of the three over the seven days? PhoneSats INFO page: http://phonesat.org<http://phonesat.org/> ________________________________ From: PhoneSat [contact(a)phonesat.org] Sent: Sunday, April 28, 2013 5:22 PM To: Kilroy, Patrick L. (GSFC-5680) Subject: PhoneSats back on Earth Dear PhoneSat followers, Our orbital analysis indicates that the PhoneSats have deorbited on April 27 and have burned in Earths atmosphere as predicted. No one has been able to hear from the satellites since, which confirms the predictions. The PhoneSat team is continuing to develop the PhoneSats using consumer technology to greatly increase the capability of the satellite whilst developing with a low cost - our next versions launching late this year so stay tuned. Thank you again for your support in making this technology demonstration successful! The PhoneSat team

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FW: Official TLEs released!
by Kilroy, Patrick L. (GSFC-5680) 25 Apr '13

25 Apr '13

FYI Save below to a text file and update your tracking software! From: Tintore Gazulla, Oriol (ARC-TH)[Stinger Ghaffarian Technologies Inc. (SGT Inc.)] Sent: Wednesday, April 24, 2013 9:10 PM Subject: Official TLEs released! Dear PhoneSat followers, We have finally received official TLEs of the three satellites. They have been updated to the website. We also add them in this email: GRAHAM 1 39142U 13016A 13114.89139670 .02066248 11824-4 11888-2 0 125 2 39142 051.6312 294.1214 0011318 353.4416 006.6606 16.18063182 484 BELL 1 39143U 13016B 13114.89029360 .02779577 11872-4 14142-2 0 147 2 39143 051.6283 294.1154 0011084 343.5055 016.9415 16.19669199 498 ALEXANDER 1 39146U 13016E 13114.89004989 .02887841 11883-4 14290-2 0 38 2 39146 051.6237 294.1128 0010785 344.8223 015.2784 16.20034403 395 I seems that Alexander and Bell are flying very close to each other and Graham is a bit more distant. As for now, the TLEs that we had seem to point more towards Graham, but we would suggest targeting Alexander and Bell. We are working on releasing the reconstructed pictures that we have so far, we still need your help to finalize the picture. Again, thank you very much for your great collaboration, we will let you know once the pictures are on the site. Thanks, PhoneSat team http://www.phonesat.org

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Orbital Launch Delayed until Friday - Maybe
by Eric Rosenberg 18 Apr '13

18 Apr '13

Orbital Sciences Corporation had planned to launch its Antares rocket from Wallops Island, Va., on Wednesday, but it was scrubbed after a crucial data cable on the rocket's upper stage became disconnected. Launch has been tentatively rescheduled for Friday. Eric W3DQ Washington, DC

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Fwd: [Tracking] PhoneSat launch April 17th! 437.425MHz
by Samudra Haque N3RDX & S21X 17 Apr '13

17 Apr '13

I am forwarding a request from NASA ARC Phonesat project, relevant to my mail earlier yesterday. This is a 3-for-1 special for amsat community. 73 de N3RDX ---------- Forwarded message ---------- From: Wolfe, Jasper Lewis. (ARC-RD)[Stinger Ghaffarian Technologies Inc. (SGT Inc.)] <jasper.l.wolfe(a)nasa.gov> Date: Wed, Apr 10, 2013 at 3:05 PM Subject: Re: [Tracking] PhoneSat launch April 17th! 437.425MHz Cc: "Guillen Salas, Alberto (ARC-SST)[Stinger Ghaffarian Technologies Inc. (SGT Inc.)]" <alberto.guillensalas(a)nasa.gov>, "Tintore Gazulla, Oriol (ARC-TH)[Stinger Ghaffarian Technologies Inc. (SGT Inc.)]" < oriol.tintoregazulla(a)nasa.gov> Hello CubeSats and Amateur Radio Operators! The very first PhoneSat’s will be launching aboard the Antares on April 17 th at 1700 EDT (launch window to April 19th possibly further). We have manifested 2x PhoneSat 1.0 and 1x PhoneSat 2.0 Beta.**** ** ** Our orbit is very low (270km x 300km 51.6deg) and we’ll only be up there for 2 weeks! So we’re looking for as many people as possible to help with tracking our satellites!**** ** ** If any of you are interested in tracking the satellite please let myself (+the cc’d team) know – your help will be greatly appreciated! **** ** ** All three satellites will be transmitting on *437.425MHz* and TLE’s + more info can be found at www.phonesat.org – consolidated info sheet attached.*** * ** ** Feel free to tune-in and submit packets to www.phonesat.org **** ** ** Cheers!**** PhoneSat Project**** NASA ARC**** ** ** This time attached :D**** _______________________________________________ Earthstation mailing list Earthstation(a)cubesat.org http://lists.cubesat.org/mailman/listinfo/earthstation

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More information on the Antares launch
by Eric Rosenberg 13 Apr '13

13 Apr '13

More for those of us on the east coast: Where the launch should be able to be seen from http://www.nasa.gov/centers/wallops/images/content/739028main_A-ONE_Visibil… (Color%20Enhanced <http://www.nasa.gov/centers/wallops/images/content/739028main_A-ONE_Visibil…>).jpg <http://www.nasa.gov/centers/wallops/images/content/739028main_A-ONE_Visibil…> Antares fact sheet - http://www.orbital.com/NewsInfo/Publications/Antares_fact.pdf There are pictures of the rollout on Flickr http://www.flickr.com/photos/gsfc/8632520054/in/set-72157633198376352/ GL! 73, Eric W3DQ Washington, DC

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Follow Up to Workshop: The GBHC This Saturday
by Kilroy, Patrick L. (GSFC-5680) 01 Apr '13

01 Apr '13

Hello fellow AMSAT Members, YOU ARE INVITED to help staff the AMSAT booth at the local hamfest in Timonium, Md. with us this Saturday! So far, it is just Ken Perko WA3WHE and me in the booth. We have a premium 1.5-hour or 2-hour slot in the schedule for you to slip in and provide a sliver of relief for one of us. Just call or write me what time you'd like to volunteer with us. All the info about the show is given below and at the GBHC Web site link shown. There is room to set up a demo or two as well. Would you like to show off part of your portable satellite ground station and laptop software in action? Please do! Otherwise just swing by to chat. You may purchase a ticket to the hamfest on the morning of, and find us in the Cow Palace like last year. This coming Saturday ought to be another fine day for Amateur Radio and satellites! Cheers, Pat N8PK n8pk(a)amsat.org The GBHC http://www.gbhc.org Greater Baltimore Hamboree and Computerfest Saturday, April 6, 2013 9:00 A.M.-4:00 P.M. Located at the Maryland State Fairgrounds 2200 York Road in Timonium, Maryland 21093 (served by Maryland-45, Interstate-83, and the Timonium Light Rail stop) P.S. . . . AMSAT NEWS SERVICE ANS-090 [snippet] + Watch a video of WD9EWK working FO-29 from the Scottsdale, Arizona Hamfest on Saturday, March 9. 2013. Patrick used two FT-817ND rigs, one for the uplink transmitter, the second to receive the downlink on a handheld ELK 2M/70cm antenna. The video is posted at: http://www.youtube.com/watch?feature=player_embedded&v=0ZhR7Doby0E P.S. 2 The Local AMSAT-DC Web Page: http://patkilroy.com/amsat-dc/ P.S. 3 A follow up note about the March 23 Workshop on Portable Satellite Ground Stations is expected in the next week or so. Certainly, a good time was had by all!

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inquiry about homebrew az-el systems
by Samudra Haque 28 Mar '13

28 Mar '13

Hi, about two years ago, I started a design for a robotics class project of a AZ-EL rotator controller system, and a hardware package for the mechanism for rotating an antenna in any direction subject to mechanical stops. The system would have been able to handle regular and flip modes. I didn't do anything more than calculations, and moved on to building a classroom instructional robot then. Lately, as I am setting up (K3GWU, the George Washington University Amateur Radio Club and Research Station) I find that the price of az-el systems such as G5500 + Yaesu AZ-EL rotors are expensive, and are not typically available on an affordable basis on Ebay or eham.net etc. Well, of course, expensive is a relative term, for a student hobby organization, it's a lot, and I guess for small ham operators it is also moderately expensive. This may be a frequently asked topic: does any one have experienced with (tested) kit designs for AZ-EL rotors that can be made with parts from current suppliers ? I know there are a number of controller designs, but I am interested to know if there are any options for suppliers of the required gears/motors etc. I have located several large AC motors / DC motors at my university mechanical engineering workshop, but they are not all guaranteed the same specs. I now realize if I do embark on a actual design process with my model/simulation/hardware, it would be nice to build several of these all at once to share the development cost over the production run, and ensure those who want a cheap AZ-EL system can get one. Otherwise the production cost of one heavy duty system is going to be quite high. I hope some of you may have suggestions for me, both (+) and (-) or perhaps (~) in nature. I thought amsat / amateur radio folks have a common need to encourage homebrew activity to keep their brain cells in working condition? I'm opening this question up to the national US audience, and welcome any discussion on the challenges of making the ever-so-important azimuth-elevation rotor. I've studied some of the alternatives: Alliance U100 and Yaesu G-5500. I think we can do better in 2013. But ideally, to allow the wide adoption of AMSAT ground stations, what price point would the system have to be to make it worth building ? 73 de N3RDX George Washington University

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Thank you & antenna links
by Stephan Greene 25 Mar '13

25 Mar '13

All: I had a great time at the AMSAT-DC meeting on Saturday. I greatly appreciated the contributions, ideas, and questions from all the participants. HUGE THANKS to Pat Kilroy and to NASA GSFC for hosting! Since I went on quite a bit about cheap antennas, here are some links to design & construction info and some related information. Cheap Antennas for the AMSAT LEO's (WA5VJB) http://www.wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf Construction suggestions, tuning, diplexer design. Also discusses performance of Arrow antenna. Cheap Yagi for 70 cm (search Amsat.org or internet for the companion 2M design) - uses foam board! http://www.amsat.org/amsat-new/information/faqs/crow/JulAug06AmsatJournal.p… Controlled Impedance "Cheap" Antennas (WA5VJB) http://www.wa5vjb.com/yagi-pdf/cheapyagi.pdf The original cheap yagi article. Designs for 2M, 220 MHz, 70cm, 902 MHz, 1296 MHz, including AMSAT and FM sections on 70cm. Great ideas for terrestrial as well as satellite ground station antennas. The 6 element 2M antenna I had with me on Saturday is VJB's 2M design and I've used it with reasonable success on 2M terrestrial (tropo, E-skip) and meteor bounce (FSK441 using WJST software). It's probably about as large as I'd want to use for a VHF rover station or portable installation. It's larger than necessary for use with LEO satellites; a much lighter boom & 3 or 4 elements are more than sufficient. There have been several published handheld designs that are 2 elements, and the Arrow (even with alleged performance issues) is a 3 element design. WA5VJB Herringbone Log-Periodic for satellites: http://www.cq-vhf.com/vhf_highlights/2012_vhf/2012_spring_vhf/2012_spring_v… Interesting design, simple, very portable (designed for hand-held). DK7ZB's designs. http://www.qsl.net/dk7zb/start1.htm Huge wealth of information here! Probably better performance than the WA5VJB designs, but more demanding of precise construction. Most of his designs are in metric units but some have English measurements as well. There are several standard inch dimension rods that are close enough to metric sizes to work. And you can get metric-dimensioned components , too. Many examples of ingenious construction techniques in the photos. His area of interest in terrestrial weak-signal communications; many of his designs are VERY optimized for 144.2 MHz and 432.2 MHz, particularly the lower impedance designs. So stick with the smaller 50 ohm designs for satellite use. The 2M/70cm-Yagis Ultralight page is probably most useful for satellite antennas. http://www.qsl.net/dk7zb/PVC-Yagis/PVC-details.htm Many of the designs are available from SOTABeams (UK) http://www.sotabeams.co.uk and as kits from Attila Kocis DL1NUX, Nuxcom, http://www.nuxcom.de. Some satellite-specific ideas & info: http://www.qsl.net/dk7zb/Cross-Yagi/crossyagi.htm Using electric fence post insulators as element mounts (especially for aluminum booms) http://www.qsl.net/dk7zb/images/Elementhalter/elementholder_fence.htm DK7ZB and WA5VJB both assume the antenna elements are insulated from the boom. If you use an aluminum boom (recycled antenna pieces, ¾"x ¾" extrusions from Lowes/Home Depot), you have to mount the elements above the boom or with insulated plugs through the boom (and worry about boom correction factors). These insulators are a good alternative. And I don't understand why the Europeans get all the cool design small parts. Less exotic looking ones are available on Ebay & Amazon (and probably at farm/horse supply stores, Tractor Supply, etc.). I purchased a big bag of them off Ebay and plan to experiment with this approach. Antenna element materials: WA5VJB recommends welding rod (cheap, elements may require splicing with hobby tubing to get lengths for 2M), #10 solid copper wire ($$), solid aluminum guy wire (old versions - Radio Shack discontinued the product several years ago), hobby tubing/rods (can get $$). Several online vendors sell a variety of aluminum rod and brass rod, some will cut to custom length at small additional cost if you are as inept as I am with hand tools! Watch shipping charges if you go over 48" in length. On the 6 element 2M antenna I displayed, I spliced the 2M driven element for that reason. The local big box stores generally don't stock small enough diameters/long enough lengths but it's worth a look. Or hit Timonium or Manassas and see what's in the flea market. Internet Vendors: http://ww.speedymetals.com http://www.onlinemetals.com (I think I ordered from them) http://www.mcmaster.com/#standard-aluminum-rods/=m17g2q [Thank you to Sambudra for reminding me of M-C] McMaster-Carr sells the rod stock in 6ft lengths; I haven't checked if they have oversize shipping charges. They sell a lot more than just metals. The above designs can make circularly polarized antennas. The 2nd set of elements is mounted at 90 degrees on the boom and is offset by ¼ wavelength (free space, I believe). It's fed in parallel with the 1st set. Since both antennas are 50 ohm designs, there are at least 2 solutions to deal with the parallel impedance: 1. Make a matching harness from coax of carefully cut and assembled lengths. 2. Purchase or build a power divider (both Directive Systems and M2 Antennas sell them), use IDENTICAL lengths of 50 ohm feedline to the antenna feedpoints. Note - According to the Directive Systems website, the company has been sold and is in the process of moving to HAYMARKET VIRGINIA this week! http://www.directivesystems.com RF Connection (therfc.com) in Gaithersubrg MD is an excellent local source of feedline, connectors, couplers, and associated parts. He can also make custom harnesses (those phasing lines). Attends all the local hamfests, so good way to save on shipping large amounts of coax across the country. I did not discuss omnidirectional antennas. The quadrafiller helix and Lindenblad were mentioned at the meeting, and Pat had a Lindenblad on display. These antennas have a reputation as difficult to build. A passive Lidenblad design was published in QST (or maybe AMSAT journal) a few years ago and looks much easier to build. No idea how well they actually perform. The local RF noise level is high enough that higher-gain antennas may be a requirement around the DC area. WB4APR has recommended for years using a low-moderate gain yagi elevated 15 degrees (some folks go for 20). Rotate in azimuth and don't worry about elevation - most passes are not close to overhead and the satellite spends very little time there. And when it is close, the shorter range and path loss make up for the loss in antenna gain (at least for smaller antennas - a very tight EME array is a different matter!) Preamps - besides the wideband RX-only model AMSAT sells, there are several sources mentioned on Saturday. Advanced Receiver Research's product list is here http://www.advancedreceiver.com/page2.html Hope this is of use to folks and look forward to the next meeting & meeting you on the air locally, and on the birds! 73 Steve, KS1G FM18 Herndon, VA -- ----------------------------------------------------------------------------------------------------------------- Steve Greene ks1g04(a)gmail.com <kay ess one gee zero four>@gmail.com -----------------------------------------------------------------------------------------------------------------

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