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

Russia Today reports Kedr deployment
by andy thomas 05 Aug '11

05 Aug '11

Guys you won't like it - brace yourself: BEGINS New satellite to commemorate first space flight permalink email story to a friend print version Published: 03 August, 2011, 20:02 Two Russian cosmonauts have left the International Space Station for a six-hour spacewalk to mark the 50th anniversary of the first-ever manned space flight by Yuri Gagarin with the launch of the unique microsatellite. The cosmonauts will spend about six hours outside the ISS and for the first time ever computerized Orlan-MK spacesuits with liquid crystal displays will give advice and instructions in case of emergency situations, such as increased oxygen consumption. During the spacewalk, the cosmonauts will launch a microsatellite made entirely by Russian university students. The satellite – which is dubbed “Kedr” (cedar) after Yuri Gagarin’s call sign – will be broadcasting greeting messages from outer space in 50 different languages to mark the 50th anniversary of the first-ever manned space flight. The cosmonauts will also install laser communication equipment on the outside of the Russian segment of the ISS. However, it does not mean high-speed internet will be available in the Russian segment, as long as “the new optical equipment is intended primarily to transfer science video to enhance the efficiency of the scientific activity of the cosmonauts,” the head of the extravehicular activity department of RSC Energia, Aleksandr Polishchuk said. With the US Shuttle program shutting down last month, Russia is currently the only nation able to send people to the stars. ENDS http://rt.com/news/first-space-flight-satellite/ and a video of the deployment 73 de andy G0SFJ

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Re: [suitsat2] Did Drew Hear Himself?
by Bill Ress 05 Aug '11

05 Aug '11

Steve - - additional, you may recall the RX tests in the clean room at your place. The RX is very sensitive having a NF (which includes the front end SAW filter) of just under 5 dB. Lou - thanks for commenting on what probably remains at the 70 CM input. I did some rough calcs and with the sensitivity of the RX and about 1.5" for an antenna, sub-microvolt signals will be heard. The 1 watt test Drew ran attests to that. So what this all means is that the transponder function is only minimally impacted by the lack of a 1/4 wavelength antenna. We need to get the word out that most typically equipped 70 CM satellite stations will make it through. Right now most everyone is focused on the easy signals but the linear transponder is almost fully functional. The very sweet thing is that with the transponder functioning we can now verify that the SDX is spot on in every way designed (Nice job guys!!) Another good test will be to exercise the command function. Now it will take a bit more power at the satellite which was by design anyway. I'm sure that's in the plan after the dust settles. Regards...Bill - N6GHz On 8/4/2011 3:30 PM, Louis McFadin wrote: > The antenna consists of a portion that is encased in grey Epoxy. > That part is about 1.5 inches long. > It's probably good enough for strong signals to get through. > SWR is not so important on a receive only antenna. > > On Aug 4, 2011, at 6:06 PM, Steven.Bible(a)Microchip.com wrote: > >> Hi Everyone, >> >> Glad to hear! I was just concerned and wanted to be sure. Then this >> opens up a lot more experimentation from the ham community. >> >> Question - How do you think the uplink is being received with no >> antenna? >> >> >> Steven Bible >> Applications Engineering Manager >> Wireless Products Division >> Microchip Technology Inc. >> Office Phone: +1-480-792-4298 >> Mobile Phone: +1-480-384-0319 >> >> >> -----Original Message----- >> From: suitsat2-bounces(a)tapr.org [mailto:suitsat2-bounces@tapr.org] On >> Behalf Of Anthony Monteiro >> Sent: Thursday, August 04, 2011 2:29 PM >> To: suitsat2(a)tapr.org >> Subject: Re: [suitsat2] Did Drew Hear Himself? >> >> Dear Friends, >> >> The transponder is inverting. The third harmonic >> would be highly distorted and opposite sideband! >> >> Also, I can confirm the transponder is working >> from hearing my own transmissions. I also heard other >> stations that were "ditters" on the downlink. >> >> 73, >> Tony AA2TX >> --- >> On 8/4/2011 4:23 PM, Joe Fitzgerald wrote: >>> >>> >>>> I am really wondering if Drew heard himself indirectly, and not >> through >>>> the transponder. There's a 3X difference between the uplink and >> downlink >>>> frequencies. >>>> >>>> Thoughts? >>>> >>> >>> >>> Drew was appropriately skeptical himself, he notes in his report: >> "Sounded >>> VERY good, and cycled on and off with the telemetry." >>> >>> -Joe KM1P >>> >>> >>> _______________________________________________ >>> suitsat2 mailing list >>> suitsat2(a)tapr.org >>> https://www.tapr.org/cgi-bin/mailman/listinfo/suitsat2 >>> >>> >> >> _______________________________________________ >> suitsat2 mailing list >> suitsat2(a)tapr.org >> https://www.tapr.org/cgi-bin/mailman/listinfo/suitsat2 >> >> _______________________________________________ >> suitsat2 mailing list >> suitsat2(a)tapr.org >> https://www.tapr.org/cgi-bin/mailman/listinfo/suitsat2 > > > > Lou McFadin > W5DID > ARISS US Hardware manager > > > > _______________________________________________ > suitsat2 mailing list > suitsat2(a)tapr.org > https://www.tapr.org/cgi-bin/mailman/listinfo/suitsat2 >

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ArissatTlm for Mac
by Gilbert Mackall 05 Aug '11

05 Aug '11

Has anyone tried this program running under Lion ? I don't have it on my development systems, but have had the question ask by some users. Gilbert Mackall N3RZN

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If you made an AO-51 contact with NY4I/Mobile Thursday around 1830Z, please read
by Tom Schaefer, NY4I 05 Aug '11

05 Aug '11

> Hi, > > I heard AO51 while I was scanning in my car so I switched the D710 to PM5 for sat ops. I worked about 5 guys. I was in rush hour traffic so could not log. If you made a QSO with NY4I mobile, please reply so I can get you logged. I know I worked Hector in Cuba last. > > Thanks > Tom Schaefer, NY4I ny4i(a)arrl.net EL88pb Monitoring EchoLink node KJ4FEC-L 489389 DSTAR Capable APRS: NY4I-15

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ARISSat-1 What a Ham Radio Achievement!
by Harry Strahlendorf 04 Aug '11

04 Aug '11

Hi Gang, I excitedly tuned my base station, connected to a dual band Ventenna on the roof, to the downlink frequency of 145.950 mHZ this morning as I tracked ISS on a pass over North America. I'm in Southern New Jersey. I was amazed to be able to hear the initial greeting female voice from this special bird! On the following pass I used a portable HT and Arrow Antenna out on the lawn and copied ARISSat-1 5X9! Thanks to all who made this possible and all who are helping us enjoy this wonderful hobby! Sincerely & 73, Harry ~ W3DNQ

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AO51 contacts today with NY4I while mobile?
by Thomas Schaefer 04 Aug '11

04 Aug '11

Hi, I heard AO51 while I was scanning so I switched the D710 to PM5 for sat ops. I worked about 5 guys. I was in rush hour traffic so could not log. If you made a QSO with NY4I mobile, please reply so I can get you logged. I know I worked Hector in Cuba last. Thanks Tom NY4I

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Two signal reports
by Philip Jenkins 04 Aug '11

04 Aug '11

145.95.Mhz, 0557 UTC, 45 degree pass here in western NC (still using the Comet quad-band vertical). Lots of fading, but I did catch that voltage was 31.5. I thought that the vertical would do ok at a 45 degree elevation, BUT I found out differently on the next pass I listened to... 145.95 Mhz, 1400 UTC, 13 degree pass to from NW to SW. (Voltage was 34.0; had just come out of eclipse a few minutes before.) I was using the Arrow antenna into the HT, and was listening to the mobile rig with the quad-band vertical at the same time. I thought the vertical would really shine at such a low-angle pass, and while it was ok, the Arrow blew it away. I knew there would be a big difference, but not a HUGE difference. With the Arrow, I heard the satellite long after I thought it would have faded entirely behind the mountain(s). Darn it, now I have to do some research on knife-edge diffraction on 2 meters around mountain tops/ridges <grin> I think I'll try the CW beacon tonight - won't be until approx 0320 UTC before the satellite is back in range, and then it's only a 4 degree pass. (70 degrees on the next one though) Philip N4HF

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em45
by wa4hfn＠comcast.net 04 Aug '11

04 Aug '11

If anyone that worked me in EM45 portable needs a QSL,send me an email with the contact info and Ill QSL WA4HFN Damon

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Feedback on BPSK decoding
by Phil Karn 04 Aug '11

04 Aug '11

I'm interested in people's comments on the reliability of the BPSK-1000 digital link in the presence of the deep periodic fading that everyone is reporting. This fading is probably because the spacecraft hasn't settled down into a stable spin around its preferred spin axis (which includes the antennas). But I designed the BPSK-1000 format to be specifically resistant to fading, so I'm really curious to see how well it's working in practice. Although the decoders don't explicitly distinguish between lost frames and idle link time (hard to do given the signal design) you can gauge the effectiveness of the decoding from the amount of data you do successfully decode per unit time. If people could estimate how many bytes per minute of decoded data they're getting, and assuming the computer doesn't let the link idle very much, that would be a good indication of how well the system is performing overall. The channel symbol rate is 1000 Hz. After rate 1/2 Viterbi FEC the actual link data rate is 500 bps. From this you have to subtract idle inter-frame time and HDLC frame overhead (flags, 4-byte CRCs, etc) that varies with the length of the frame, leaving the data. So in 1 minute you could receive up to 3750 bytes of binary user data. How close are people coming to this figure? Phil

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Moans and Groans
by johnag9d 04 Aug '11

04 Aug '11

Yes! It is something that should be asked. We know from the so called test and the Yuris Night deal that the bird was used in ways not previously known. So either the antenna broke off or was not attached. This was not the crew that would have deployed in February. As has been said before beggers can't be choosers. If interested people pony up the bucks we can build and pay to launch anything and be autonomous. The reality is that raising several million dollars is not going to happen. So we take what we can get for now and celebrate the good as best we can. ARISSAT from my understanding was always what it is an education sat. The fact it has a transpoonder was a nice add on thanks to SDR and a test for the Fox platform. It was not advertised as an amateur only bird. ---------- Sent via Cricket Mobile Email

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