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

Terrestrial QRM to AO-27 and SO-50
by Bob Stewart 03 Oct '07

03 Oct '07

I may have found the culprit, though I'm not entirely sure, yet. I've sent an email to the group that I found, and I'll report back on the results. It seems to be in the right area. Bob - AE6RV

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AMSAT Space Symposium
by Martha 03 Oct '07

03 Oct '07

For those people who would rather not register for the Meeting through the AMSAT store, you can register via phone by calling 301-589-6062. Don't forget to go to the website and check out the Symposium apparel! -- 73- Martha

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October 4th 1957.
by John Hackett 03 Oct '07

03 Oct '07

Enjoy!. <http://news.bbc.co.uk/2/hi/science/nature/6937964.stm> 73 John. <la2qaa(a)amsat.org>

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October 4th 1957.
by John Hackett 03 Oct '07

03 Oct '07

Ladies and Gentlemen, (Yes, there ARE ! several Ladies among the satellite enthusiasts). Never mind the bickering re: schedules etc regarding the sounds emitted from the steel ball on the 4th of October 1957. For those not managing to catch it via AO-51 you can always listen to the original recording ... (and many, many more) ... on the following web page ... <http://www.dd1us.de/historical%20sounds%20from%20space.html> 73 John. <la2qaa(a)amsat.org>

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Re: Terrestrial QRM on AO27 2100z pass
by John Marranca, Jr 03 Oct '07

03 Oct '07

Dave: Yes, it was pretty bad. I worked you on that pass...and it was a bear. One thing that I DID realize, however, is that not only was AO-27 in range at 2100, but SO-50 was also. I wonder how much interference was caused by that happening. Anyway...thanks for the QSO. 73 de 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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mutual windows between GB5OSO and NA 4th Oct
by Robert Turlington 03 Oct '07

03 Oct '07

NOVA indicates that there are a number of mutual windows between GB5OSO and NA ao7:- 1200,1353,2112 (east coast USA) so50:-1019,1201,1343,1524,1705,1847 (east coast Canada)VO52:-1321,2248 (east coast Canada) I will call CQ in the middle of the linear passbandRegards Robert G8ATE (GB5OSO) _________________________________________________________________ Feel like a local wherever you go. http://www.backofmyhand.com

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Winlink Positions on APRS
by Robert Bruninga 03 Oct '07

03 Oct '07

During yesterday's Satellite demo of APRS via GO32: As I was zooming in on Annapolis, Maryland, to see our own station, the map seemed lit-up with more stations than usual. As I zoomed in to the mile scale, the area was full of APRS reporting boats. http://mm.aprs.net/map.cgi?map=APRSworld&lat=39&lon=-76.5&call=* &range=.5 Then I realized it is the annual boat-show weekend. On closer inspection, it seems these position reports are not on APRS VHF, or APRS Satellite, but are on WinLink HF. Steve's APRS FINDU.COM engine collects them from WinLink and adds them to the APRS system! Now, with the APRS format for including operating frequency in all position reports (and built-into the D710 radio), once that is integrated with the WHOIS system, then we will have one picture for all of ham radio for finding other hams and their operating frequency. See: http://www.ew.usna.edu/~bruninga/localinfo.html Bob, WB4APR

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Earth imaged by Japanese Lunar probe
by Kevin Forbes 03 Oct '07

03 Oct '07

>From the Radio Jove list ---------------------------------------------------------------------------------------------- Hi All, Good news! The Earth taken by the onboard HDTV of the KAGUYA http://www.jaxa.jp/press/2007/10/20071001_kaguya_e.html The KAGUYA is equipped with Jupiter radio receiver. The frequency range is from 10kHz to 30MHz. The sweep rate is every 2 seconds. Our Jupiter radio scientist is considering the simulataneous observations from ground observing stations. RadioJOVE on the moon may be possible. (^^); Professor and Dr. Kazumasa Imai Kochi National College of Technology, Japan http://www.ee.kochi-ct.ac.jp/~imai/drimai.html ---------------------------------------------------------------------------------------------- _________________________________________________________________ Advertisement: It's simple! Sell your car for just $30 at CarPoint.com.au http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fsecure%2Dau%2Eimrworldwide%…

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Re: SUD (Small Ugly Dish)
by Eric H Christensen 03 Oct '07

03 Oct '07

Sil, I look to Robert W0LMD (and others) for information on patch feeds. You may want to check out http://www.ultimatecharger.com/dish.html to see some projects that were done on the larger dishes. 73s, Eric W4OTN >Eric, > >I've googled and looked in more traditional places for generalised >design data for patch antennas but come up empty handed. If you can >suggest anywhere I might find some engineering design guides I'd be very >happy. I want to build some for various frequencies, not just 2,4 GHz. > >Thanks > >Sil > > >Eric H. Christensen wrote: >> Thanks Bob. I figured as much but I thought I'd ask. I'm going to try >> to set it up for S-band operation. I'm going to try to build a patch >> from ordinary items from around the house. Maybe I can document it and >> show others how to build their own setup to help demystify 2.4GHz. >> >> >> 73s, >> Eric Christensen, W4OTN >> AMSAT Area Coordinator - Southeastern Virginia USA >> AMSAT Member 35360 >> http://www.ericsatcom.net >> >> Donate to the Eagle Fund - >http://www.amsat-na.com/donation.php?donate=eagle >> >> >> >> Bob Bruninga wrote: >> >>>>Back to my "new" [18"] dish... Being that it >>>>is an offset dish, is 1.2GHz possible with >>>>this dish? >>> >>>No. >>> >>> >>>>Anyone tried this? >>> >>>Yes. I tried it for our satellite labs for students and althogh I get about >14 dB or so measured gain with it at 2.4 GHz, at 1.2 GHz, it was nothing more >than a big piece of metal giving no more gain than a flat reflector... maybe >between 3 to 6 dB. >>> >>>See the photo of its use at 2.4 GHz on the top of this page: >>> >>>http://www.ew.usna.edu/~bruninga/ea467.html >>> >>>With the antenna for one of those $75 wireless camera receivers at the focal >point, and the companion little wireless camera as a signal source a mile away >with only its 1.5" whip antenna, we receive the picture perfectly with a >margin of at least 16 dB. This means the picture would still be good out to >maybe 6 miles... >>> >>>It sure is an easy way to get into Amateur TV. Even though it does not even >require a license.. >>> >>>But if there are wireless LANS around, then the picture gets lots of QRM.. >>> >>>Bob, Wb4APR >>> >> >> >> _______________________________________________ >> 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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Re: Keep It Simple, MM
by Frank H. Bauer 03 Oct '07

03 Oct '07

I feel compelled to comment on one specific item that Dave questions in this thread---surface mounted components in space. I have worked at NASA for 32+years and have led or guided avionics teams throughout NASA for a large part of that time (15+ years). For many years we have used surface mount technology in our avionics products. I was quite proud of our (Goddard) surface mount capabilities. One of our techs was an expert on the installation, removal and replacement of surface mount components.an expertise that is highly sought after. This technology is a mainstream capability within the space community. So I need to say that this myth is "busted" 73, Frank, KA3HDO Date: Mon, 01 Oct 2007 22:20:55 -0400 From: "David B. Toth" <ve3gyq(a)amsat.org> Subject: [amsat-bb] Re: Keep It Simple, MM To: MM <ka1rrw(a)yahoo.com>, amsat-bb(a)amsat.org Message-ID: <6.2.3.4.2.20071001220931.03f3beb0(a)pop3.wcoil.com> Content-Type: text/plain; charset="us-ascii"; format=flowed At 08:06 AM 10/1/2007, MM wrote: >Keep It Simple Silly KISS >By Miles WF1F > >The direction of this tread is caution. I am not suggesting that we do >not use digital technology for satellites, just that we need to be >careful of the technology. The Space environment is not kind to >digital circuits. Digital circuits are easily corrupted by solar >radiation and thermal stresses. A digital circuit designed for use on >Earth many not survive the rigors of outer space. This is partially >because of the Size of a transistor inside a modern CPU. > >In 1978 a computer transistor was made up of wires 3 microns in size. >Today's CPU Itanium, uses wires 0.18 microns in size. The new DSP >chips used on Digital radio will be some where in-between. With the >wire sizes in the 0.20-micron range, it's much easier for solar >radiation to cause temporary shorts, which can cause system crashes. The SDX is a software-defined radio ... it does not necessarily, and probably does not, use a DSP chip. >Keep It simple. A small satellite that does one or >two features is better than one big satellite that >does 10 big features. At the cost of launches and satellites, i think this point is easily disputable. I am sure that the engineers are looking at an overall systems approach, AND they've done this before. The difference is the addition of a software-defined approach, which WILL be space-tested in SuitSat2 anyway >Axle lead Resistor and through-hole mounting of >components are much more resilient in space than >surface mount components. Miles, do you have any data to support this statement because right off-hand, I can't see why this would be true. >Hardware is not your only problem; you also need to >Extensively Test the software that runs the satellite >project. This is not the first satellite these guys have built - I think they had this somewhere on their "To-Do List" ... >The Analog satellites AO-7 (launched Nov 1974) and >AO-10 (June 1983) are still there when the sun is >shining. Well, that is actually a bug, not a feature. We need to have a way that we can guarantee that when a satellite dies, it STAYS dead. That was a real sticking point with Larry Kayser when he was still alive. These things pop up, un-controlled, and if we had enough of them, they'd be an interference problem. Dave

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