February 2011 - AMSAT-BB - mailman.amsat.org

ARISSat-! Demodulation
by santanaamt＠aol.com 10 Feb '11

10 Feb '11

Tnx for response: It is to have a more clear view of the way to work it cause of it's various modes, and to later explain if someone locally asks, I do post info on local reflectors and know there are amateur satellite fans in KP4. Siete Tres y Gracias de Angel - WP3GW

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ARISSat-1 decoding software release
by Gould Smith 10 Feb '11

10 Feb '11

As I posted on Monday, the ARISSatTLM software is not yet ready for distribution. We are still testing it. We expect to release the free ARISSatTLM software next week. This software will demodulate, decode and display the BPSK-1000 telemetry and Experiment data as well as the CW signal. There will be both PC and Mac versions. 73, Gould, WA4SXM AMSAT ARISSat-1 Project Manager

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ARISSat-1 Demodulation
by santanaamt＠aol.com 10 Feb '11

10 Feb '11

Hello to the group: Have been reading about the satellite and BPSK 1000,but then have a little doubt on two subjects: 1- The BPSK 1000 part, can be decoded on FM, SSB or a combination of both? 2- In the same line, if one TX to it on U/V, what is the mode to use? 70cmUSB/2mLSB, 70cmLSB/2mUSB and/or 70SSB/2mFM? Thanks in advance. Angel - WP3GW

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Decoding Software for ARISSat-1
by Clint Bradford 10 Feb '11

10 Feb '11

The Web site that Carlos is using to host the decoding software is giving browsers' "security warnings" and "invalid certificates" messages. Can "we" assist Carlos and host his wares somewhere else? I realize that going to his site is probably all fine ... but the warnings are enough to possible scare some away frm the project. Clint Bradford, K6LCS - - - - - - - - - - - - - - - - - - - - - - - - - - - This Connection is Untrusted You have asked Firefox to connect securely to svn.sarpeidon.net, but we can't confirm that your connection is secure. Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified. .... If you usually connect to this site without problems, this error could mean that someone is trying to impersonate the site, and you shouldn't continue. Technical Details svn.sarpeidon.net uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. (Error code: sec_error_unknown_issuer) /end/

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Re: ARISSat-1 - Dumb Question
by G0MRF＠aol.com 10 Feb '11

10 Feb '11

Thank you Greg. Makes sense to me now. Also, just calculated the velocity of a 90 minute LEO orbit and the velocity of a geostationary 24 hr orbit using circumference and time. Found that the velocity at LEO is higher, so presumably the decrease in orbit altitude of Arissat due to decay must also add acceleration. (Gravity) 73 David G0MRF In a message dated 10/02/2011 05:26:00 GMT Standard Time, ko6th_greg(a)hotmail.com writes: From: G0MRF(a)aol.com > Date: Wed, 9 Feb 2011 15:45:36 -0500 > To: clintbradford(a)mac.com; amsat-bb(a)amsat.org > Subject: [amsat-bb] Re: ARISSat-1 - Dumb Question > > Hmm. This is a bit of a brain teaser... > > So if the satellite is deployed towards the rear of the ISS, it's velocity > will be slightly lower. > So does that mean it will go to a lower orbit- (Same as firing retros to > reenter)? > > If so, then I believe as the orbit altitude is reduced, the apparent > velocity increases.....(??) which will cause ARISsat-1 to 'move ahead' of the > ISS over a few hours > > But didn't we say the velocity would be less than the ISS due to the method > of deploying it against the velocity vector ? > > Time for me to have a Tuna sandwich. We all know it's probably full of > Dolphin...and they are really clever. > > David G0MRF > Interesting puzzler, eh? From what I have read in the past, I think this their logic. What they are trying to do is to separate the orbits of the ISS and ARISSat as quickly as possible, to avoid the potential for a collision. Consider the options: 1. Throw it sideways to the ISS orbit. The result is that twice per orbit the two spacecraft's paths will cross, side to side. Bad idea. 2. Throw it ahead of the ISS (faster orbit speed). This will raise the orbit, slightly, and also make it a bit elliptical (up and down). The higher orbit makes the satellite go behind the ISS, but the elliptical shape also means that the orbits will cross every orbit (but out of phase, so they won't be at the same place when they do). But, then as the ARISSat orbit decays, they will get closer and closer, potentially getting back to the same place. Not good, either. 3. Throw it behind the ISS (slower orbit). As you note, this will lower the orbit (and make it a bit elliptical), and initially the apogee of the orbit will intersect that of the ISS. Being in a lower orbit, ARISSat will move ahead of the ISS, and over time, as the ARISSat orbit decays, the two will diverge even farther. So, this is the safest. At least, I think that's the logic. If not, pass me some of that tuna... Greg KO6TH

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ARISSat-1 Telemetry decoding
by Nitin Muttin 10 Feb '11

10 Feb '11

I downloaded and installed the application for decoding the ARISSat Telemetry, is there a test wav file to check if the app is working on my PC and also does this send the decoded telemetry data to the ARISSat team thry internet. 73's Nitin [VU3TYG] Secretary, AMSAT INDIA

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Spacewalk From International Space Station Will Air On NASA TV
by Marc Tessier - VE3TES 10 Feb '11

10 Feb '11

This could be the launch/release of ARISSAT, I for one would love to have a VCR setup but time will tell... P.S. I received this information from my NASA news forwarded email... Spacewalk From International Space Station Will Air On NASA TV Tue, 08 Feb 2011 23:00:00 -0600 Two Russian cosmonauts will step outside the International Space Station on Wednesday, Feb. 16. NASA Television coverage of the spacewalk will begin at 6:45 a.m. CST. This e-mail update was generated automatically based on your subscriptions. Some updates may belong to more than one category, resulting in duplicate notices. __________ Information from ESET NOD32 Antivirus, version of virus signature database 5860 (20110209) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

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Wanted: UHF Preamp
by Zachary Beougher 10 Feb '11

10 Feb '11

Hi! Does anyone here have a good UHF preamp that is sitting in a corner collecting dust that I could use on my Arrow or mobile satellite setup? I would never run anymore than 25w through it – I would be lucky if I did 10w. I weatherproof model would be preferred, but not 100% necessary. I thought I would check here before I go looking at all of the commercial retailers. 73! Zack KD8KSN

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demo
by Nick Pugh K5QXJ 09 Feb '11

09 Feb '11

Hi all I am giving a demo to a middle school in Lafayette LA EM30 . It would impress the students if you could come up on Echolink node 370324 at 10:20 CST Thursday and help demo to the 7th graders. If you can make it please respond to this email. Thanks nick Office 337 593 8700 Cell 337 258 2527 Helping UL become a world Class Engineering and Educational School

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BPSK 1000
by Pete Norris 09 Feb '11

09 Feb '11

I am trying to find BPSK 1000 on GNU website. I can't find the code they mention. I would appreciate someone telling me what I am missing or doing wrong. I am running Windows. Many thanks, Pete, K1HZU

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