December 2007 - AMSAT-BB - mailman.amsat.org

Call for Papers--2007 ARRL/TAPR Digital Communications Conference
by Ford, Steve, WB8IMY 16 Jul '12

16 Jul '12

Technical papers are solicited for presentation at the 26th Annual ARRL and TAPR Digital Communications Conference to be held September 28-30, 2007 in Hartford, Connecticut. These papers will also be published in the Conference Proceedings (you do NOT need to attend the conference to have your paper included in the Proceedings). The submission deadline is July 31, 2007. Please send papers to: Maty Weinberg ARRL 225 Main St Newington, CT 06111 or you can make your submission via e-mail to: maty(a)arrl.org Papers will be published exactly as submitted and authors will retain all rights. 73 . . . Steve, WB8IMY ARRL

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Santa docks at the ISS
by Ed Tump 25 Aug '08

25 Aug '08

Happy holidays! I got a kick out of this video: http://youtube.com/watch?v=_Di8mZLu0VE <http://youtube.com/watch?v=_Di8mZLu0VE&feature=PlayList&p=26B9B2ACB4AAC849& index=7> &feature=PlayList&p=26B9B2ACB4AAC849&index=7 Maybe he dropped off some more amateur radio gifts. 73, Ed KC9GWK Grid EN52 AmSat Member

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Re: FYI -- One Laptop per Child (OLPC) Opportunity
by Tom Clark, K3IO 23 Jan '08

23 Jan '08

(I posted this a couple of days ago, but it was never released from amsat.org limbo. So I resend. My order for OLPC went in today -- they accept either PayPal or plastic -- Tom) Another thing I gleaned from the OLPC wiki is that it supports FORTH (start at http://wiki.laptop.org/go/Forth_Lesson_0). Karl (DJ4ZC) designed Phase-3A back in the late 1970's and the onboard computer (IHU) used the computer language that Karl wrote called IPS (Interpreter for Process Structures) based on FORTH, but with German syntax and multi-tasking real-time support. Several of us (W0PN, W1HDX, ZL1WN, DB2OS & I) ported the German "dialect" of IPS into English and the "Gerglish" IPS has served as the basis for running all the Phase-3 IHUs up thru AO-40 (thanks to the efforts of W4SM and G3RUH). IPS is also planned for P3-E (N4HY already has it running on the new IHU) and probably P5. As another possible AMSAT/OLPC synergy, I can easily envision the OLPC Forth kernel being adapted to real-time control tasks with the addition of Karl's "chain". Although it is really modest compared to the normal laptop, Nick Negroponte and his team has really come up with a platform that has amazing possibilities! Meanwhile, ASUS has introduced their commercial Linux-based "Eee" miniature notebook that is already available ($399 from Amazon <http://www.google.com/pagead/iclk?sa=l&ai=BuJiyAGg3R9XlK4iaeuyDjLIMqprePM7t…>) -- Just Google ASUS Eee <http://www.google.com/search?q=Asus+Eee&sourceid=navclient-ff&ie=UTF-8&rlz=…> or see the Eee wiki entry <http://en.wikipedia.org/wiki/ASUS_Eee_PC#Storage> for details. 73, Tom

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FS: Kenwood TS-790A + IFD board + TNC31S
by Francisco Costa, CT1EAT 19 Jan '08

19 Jan '08

Dear AMSAT friends My pacsat station is for sale: Kenwood TS-790A 144/432/1200 MHz transciever ============================================ with the following extras: * UT-10 1200 MHz module * Symek IFD-B board (for speed up to 76000 bd) and mods: * extended rx (on 3 bands) * 9600 baud tx/rx * 100ms mute disabled * IFD-B board (38400 baud rx) plus: * Hand microphone * DC cable * Instruction Manual (in english) include schematics * External Control Instruction Manual (in english) * Modifications documentation (in english) All mods were performed by me and no holes were done. This equipment was bought new (1997), and until now there was not a single problem! It was kept on a non smoking environment. Cosmetic is a 8/10 (one minor dent, sort of paint bubble and 4 rotator control box feet "stain", all on top cover) Unfortunatly I don't have the original box anymore. Sorry TNC Symek TNC31S ================ * Tx 9600/Rx 38400 baud card * 128kb RAM * 512kb Flash-EPROM * English mailbox * Kiss autostart including: * RS232 cable plus adapter (DB9) * DC cable * Diskette with software * Original Manuals (english and german) This TNC was bought new (2000), and was used on UO-36 and Tiungsat-1 with great sucess. I did't use it since a long time ago, but I belive it's 100% operational. Cosmetic is 9/10. I will only sale the 2 items together. Price: 1500 Euro Buyer pays shipping. Payment methods: Euro countries: Bank money transfer only! Elsewhere: Western Union or PayPal. Photos: please visit http://ct1eatsale.no.sapo.pt/ Thanks for your attention. See you on P3E or Eagle. 73 F.Costa, CT1EAT www.qsl.net/ct1eat

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FS: Items for sale
by K7XQ 04 Jan '08

04 Jan '08

Have a few items for sale. Thought I would put them here locally just in case Someone might be interested before considering putting them on e-bay. * FT-736R 144 and 432 all mode satellite transceiver w/220 MHz module, hand mike and manual $800.00 plus shipping unless local pickup * Mirage 2512G 220 MHz 120 watts amplifier w/ preamp $250 plus shipping unless local pickup I actually see 150 watts out of this one * KJ6KO 60-70 watt 1296 SS Amplifier $200 plus shipping unless local pickup only used once, takes +28 VDC * MFJ-993B Automatic antenna tuner only used once like new condition $200 plus shipping unless local pickup ONLY trade considered would be a fully functional in good condition Yaesu FT-847 for entire package. I also have paypal. K7XQ Jeff Atwater, CA.

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ISS power output ?
by Andrew Rich 02 Jan '08

02 Jan '08

Does anyone know what power the ISS is running on 145.825 ? I see it is a D700, perhaps on 5 watts ? ---------------------------------------------------------------------------- Andrew Rich VK4TEC vk4tec(a)people.net.au http://www.tech-software.net

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Re: Making your own rotator controller
by Henk, PA3GUO 01 Jan '08

01 Jan '08

Hi Andrew, Not exactly an answer to your question, but still: Some years (~1995..1996) ago I built my own tracker as well. Was the time when the LVB trackers etc were not available. Only the expensive Kansas City tracker (expensive). My system is still operational. Bertus, PE1KEH, wrote in PASCAL the tracking SW (input: kepler, output: sat position). I added to that the controlling of the rotors. All corrections mentioned below (overshoot etc) are done in PASCAL in the PC. That sends and integer value to the ST6 (like your PIC) which does only one thing extra: check if the integer exceeds the allowed maximum right or left position (in case max left is at 4.5V where your range maybe 0..5V). Items to consider next to straight degrees2voltage conversion: - overshoot (when you stop, the rotor actually moved still a tiny bit) - thresholds (to avoid oscillation & to much shaking) 8 bits give enough accuracy, I used a pot.meter to convert the voltage of the rotor voltage from eg 0..20V down to 0..5V. http://home.vianetworks.nl/users/hamoen/pa3guo/zb_rtr_ctrl.html (includes my poor PASCAL routines) Of course it took a terrible amount of effort/time, which I had only back then, so today I would buy an LVB tracker :-) Still - this was one of the most satisfying projects I ever did. Seeying you home-made system following the bright ISS in the darkness of the night is soooo cool ! Have fun & success Henk, PA3GUO http://www.qsl.net/pa3guo

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Re: Wishing you a fantastic 2008 !
by John Marranca, Jr 31 Dec '07

31 Dec '07

Henk and All: I second that! 2007 has been a good year for me personally, professionally, and avocationally. It has been a privilege to meet so many fine people that enjoy these satellites as we do. Everyone I have met in AMSAT, and via Satellite has exemplified what it means to be a ham...in the true original spirit of Amateur Radio. Be well, be happy, be healthy, and be prosperous in 2008 my friends. John KB2HSH -- _______________________________ John Marranca, Jr PBX Technician/Shop Steward CWA Local 1122 BN Systems, Inc Orchard Park, NY (716)972-2006

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Re: Dont loose the north
by Tom Clark, K3IO 31 Dec '07

31 Dec '07

Jim, ZL1TYF is correct in his interpretation. My QTH is about 35 km from BWI (Baltimore-Washington Int'l) airport and is also on the Boston/NYC/Philly/Washington/Atlanta/Miami east-coast corridor, so a lot of high altitude planes pass overhead, These show up as a thin line (cabin lights) and dots (wingtip beacons). The bright curving traces are from planes landing or taking off from BWI. The Aurora animated GIF, you will see one BWI plane whose track split between two of the individual frames. In these pictures, the shutter was held open for 88 seconds, and then 2 seconds of dead-time allowed for the JPEG frame to be written to the CF card memory, so a new frame began every 90 seconds. The two long exposure star trail photos were made by stacking a number of these photos (140 for the non-aurora picture), each one on top of the previous frame. The stacking algorithm involved a pixel-by-pixel search. If the new pixel was brighter than the old one, then the new pixel was saved. If not, the the older, fainter pixel was kept. This is to be contrasted with the normal "open the shutter for an hour or two" scheme because the black background (due to stray skylight and sensor noise) doesn't "blow up". To do this processing, I used Max Lyon's Image Stacker software (http://www.tawbaware.com/imgstack.htm). If you view the 4-hour "140" picture at maximum resolution (http://www.pbase.com/tomcat/image/5186538/original.jpg), you will see that the star trail lines are dashed, due to the 88/2 second timing. The earth did rotate under the stares during the 2 second gap! If you look at this picture you will notice a gap about 2/3 of the way along each arc. This is due to the Canon D60 I was using at the time running out of battery power. It took me a few minutes to realize that the pictures had stopped. The reason the 4-hour picture was restricted to 140 JPEG frames is because, at the time, the biggest CF card I had was 256 MBytes in size. Although the camera produced 6 MPixel images, the individual frames were only ~1.5 MBytes because the JPEG compression (quite similar to ZIP & RAR) squeezed a lot of black pixels down to only a few bytes! (I really need to try a long overnight picture with my new 40D (thanks, Santa) camera equipped with a huge 8 GByte CF card.)

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Wishing you a fantastic 2008 !
by Henk, PA3GUO 31 Dec '07

31 Dec '07

Dear friends, Here in Europe we have about 6 hours left in 2007. Let me take to opportunity to thank you all for the fun we had together this year with our beloved satellites. And to all of you: a fantastic 2008 ! 73's Henk Hamoen, PA3GUO

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