May 2013 - AMSAT-BB - mailman.amsat.org

Re: ISS HamTV Frequencies (range gain)
by Robert Bruninga 16 May '13

16 May '13

One needs to also realize duration. The time say above 70 degree elevation (where rates are highest) are less than 2% of the total pass times. Not worth worrying about. Similarly, a LEO satellite spends 70% of its time below about 22 degrees. (but it is far away and needs max gain). So simply design for the best operation for most of the time when the link will work. Remember, the satellite is 3000 km away on the horizon and very weak, but as it gets into say 1500 km it is twice as close and 4 times (6 dB) stonger which is a heck of a lot of gain. When it goes directly overhead it is another 6 dB closer which is more than *ten* times the signal on the horizon, so don't worry about the 2% of the time it is going to be above 70 degrees. The signa is 10 times stronger and easy to deal with. Bob, WB4APR -----Original Message----- From: amsat-bb-bounces(a)amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Art McBride Sent: Monday, May 13, 2013 12:44 AM To: 'Roger'; amsat-bb(a)amsat.org Subject: [amsat-bb] Re: ISS HamTV Frequencies Roger, A SWAG, (Wild Guess) 1 degree per second at a Zenith of 90 degrees. Anything less than 90 degrees will be slower with several minutes spent near the horizon. You can use an orbital program to get exact numbers. With a wide beam width antenna, the lag overhead may never require the antenna to move with the object, as there will be time for the antenna system to catch up after passing overhead. Art, KC6UQH -----Original Message----- From: amsat-bb-bounces(a)amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Roger Sent: Sunday, May 12, 2013 2:34 PM To: amsat-bb(a)amsat.org Subject: [amsat-bb] Re: ISS HamTV Frequencies Anybody off the top of their heads know how many degrees a second swing are (is?) required for direct aim at the ISS? I know there are beam width tolerances, altitude variations and degree above horizon variations but I'm looking at Bob B's fixed antenna aiming of 15-20 degrees above horizon to evaluate swinging a dish without torque eating up the drive train... Roger WA1KAT On 5/12/2013 5:01 PM, M5AKA wrote: > The AMSAT-UK page at > http://amsat-uk.org/2013/05/12/hamtv-from-the-iss/ provides the links, they are: > > Facebook https://www.facebook.com/Hamtvproject > > More information at > http://www.amsat.it/Amsat-Italia_HamTV_brochure.pdf > and http://www.amsat.it/Amsat-Italia_HamTV.pdf > > The HamTV.pdf gives the link budget, looks like there's 7dB of coax/connector losses to overcome between the ISS transmitter and the antenna. That document indicates a 90cm dish should be sufficient. > > I believe that it's going up on ATV 4 which is currently slated for > June 5. > > 73 Trevor M5AKA > > _______________________________________________ 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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TurkSAT
by K4FEG 16 May '13

16 May '13

Hello everyone! 2 questions: 1) is anyone hearing the beacon on TURKSAT? 2) if so, what TLE's are you using? I did not have things set up right after the launch so I missed out on the initial beacon that was heard by many around the world. thanks, K4FEG

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Re: ISS HamTV Frequencies
by I0ELE 16 May '13

16 May '13

Certainly! You can find the nominal link budget on http://www.amsat.it/HAMTV_Link-budget-IARU.pdf and all the relevant information http://www.amsat.it/Amsat-Italia_HamTV_brochure.pdf. However * Recommended Antenna gain > 25 dB * RHCP * Low noise down converter i.e. Kuhne LNC 25 or LNC 25 TM NF 0.7 dB * Any DVB-S Decoder which can decode a 1.3 MSym/s TV signal 73, Emanuele, I0ELE President AMSAT Italia

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Fox and ISS Ham-TV
by Les Rayburn 16 May '13

16 May '13

First of all congratulations to the entire Fox team. I know that everyone is excited about the possibility of another FM bird in the near future. As for Ham-TV, I agree that more information about the ground station requirements would be most welcome. I just managed to win a TechnoTrend S2-1600 HDTV satellite PCI Card on ebay ($60 bucks with shipping) so I hope this is a good start on a complete station. The next hurdle for me will be assembling a workable antenna and I assume an AZ/EL rotor with automatic tracking? It does seem like information is incomplete considering how close to the go live date we are. I know that this type of digital TV is in wide use in Europe, so maybe some of these folks can lend the yanks a hand? -- -- 73, Les Rayburn, N1LF 121 Mayfair Park Maylene, AL 35114 EM63nf 6M VUCC #1712 AMSAT #38965 Grid Bandits #222 Southeastern VHF Society Central States VHF Society Life Member Six Club #2484 Active on 6 Meters thru 1296, 10GHz & Light

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Office Closed
by Martha 15 May '13

15 May '13

The AMSAT Office will be closed on Thursday, May 16th, Friday, May 17th and Monday, May 20th. Hope to see you in Dayton. -- 73- Martha

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ANS-134 ANS Special Bulletin - NASA Announces Fox-1 Launch Date
by JoAnne Maenpaa 15 May '13

15 May '13

AMSAT NEWS SERVICE SPECIAL BULLETIN ANS-134 SB SAT @ AMSAT $ANS-134.01 ANS-134 ANS Special Bulletin - NASA Announces Fox-1 Launch Date AMSAT News Service Bulletin 134.01 >From AMSAT HQ SILVER SPRING, MD. May 14, 2013 To All RADIO AMATEURS BID: $ANS-134.01 NASA announced Monday that AMSAT's Fox-1 spacecraft has been assigned for launch in 2014. For details on the launch vehicle, targeted launch date, orbit specifics, and more, please attend the AMSAT Forum or visit the AMSAT booth at the Dayton Hamven- tion this weekend. Watch http://www.amsat.org and the AMSAT News Service for more details to follow. [ANS thanks AMSAT Vioe President Engineeing Tony Monteiro, AA2TX for the above information] /EX

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Help regarding working of RCI SE
by Aayush Yadav 15 May '13

15 May '13

Hi, We are facing problems in automating the antenna in our ground station. The RCI SE board is not being detected by the computer. So we are not able to give any command through it. We are using RCI SE board ( by EA4TX) with yaesu g5500 rotor. Please can anyone help us. Regards, Aayush Yadav, Pratham, student satellite project, IIT Bombay.

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1973-05-14: Launch of Skylab 1
by B J 15 May '13

15 May '13

http://www-pao.ksc.nasa.gov/kscpao/history/skylab/skylab-1.htm 73s Bernhard VA6BMJ @ CO96NG

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ISS ham TV
by Robert C. Campbell 15 May '13

15 May '13

I am so confused. Is anyone going to make up a paper, ISS HamTV for dummies? I would like to work on this project but there does not at this time seem to be an easy shopping list, with connect tab a to slot a. I would hope there is something more clear in time to get a build done and ready by July. A mobile tv manager that runs the sports circuits for US tv networks says we will be waiting for our European hams on this one. Even the Tutionne web site confuses me.

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adjusting for Doppler
by Rolf Krogstad 14 May '13

14 May '13

I am sure this has been hashed over in the past but as a novice to the birds I am not sure how to proceed when operating one of the linear transpondesr. I looked at the latest editions of two ARRL publications: ARRL Operators Manual, edition 9, copyright 1007-2011 ARRL Satellite Handbook, copyright 2010 Both are very clear about how one should allow for Doppler shift on the linear transponders. One clearly says find your spot and then use the downlink VFO to adjust for Doppler shift, don't touch the uplink VFO after the initial setting of the frequency. The other clearly says find your spot and then use the uplink VFO to adjust for Doppler shift, don't touch the downlink VFO after the initial setting of the frequency. Color me confused... Rolf NR0T Amsat #38889 EN34

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