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

Winterization project
by Greg D 02 Sep '13

02 Sep '13

Hi all, As I reported on the 20m Amsat Net (14.282mhz Sundays 18:00z - 19:00z) this morning, I noticed that my 2m antenna was listing slightly down-hill. Suspecting that the boom attachment screws had come loose, my project for the day was to go up on the roof and align and tighten them. The screws were a little loose. That's not why the antenna was drooping down. I discovered the real reason: Acorns. Apparently the local squirrels have been preparing for winter, such as it is around here, and had stuffed about a dozen plump acorns into the open end of the antenna boom. Besides their weight climbing out to the end, there was also the remaining weight of the acorns. So, the antenna ends have been taped over, but that's not going to prevent the squirrels from climbing out onto the antenna. Any suggestions on an effective squirrel deterrent? Greg KO6TH

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Another successful CubeSat Kickstarter
by M5AKA 02 Sep '13

02 Sep '13

The LunarSail project has completed a successful Kickstarter. As yet the project has no launch but hopes to be able to get a free one from NASA. They appear to be planning to use a Raspberry Pi computer board, see http://amsat-uk.org/2013/09/02/successful-kickstarter-for-raspberry-pi-luna… ---- 73 Trevor M5AKA AMSAT-UK website http://amsat-uk.org/ Facebook https://www.facebook.com/pages/AMSAT-UK/208113275898396 Twitter https://twitter.com/AMSAT_UK ----

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Re: Squirrel Repellant
by Clint Bradford 02 Sep '13

02 Sep '13

Go to your local nursery. They will have solutions (there's a pun there) - including urine of other animals (usually LARGER animals (grin)) or placing a ring of "barbed" wire on the mast - making it un-climb-able. Clint K6LCS

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Re: Winterization project
by Jeff Griffin 01 Sep '13

01 Sep '13

A 12 gauge full choke shotgun ? 73 Jeff kb2m -----Original Message----- From: amsat-bb-bounces(a)amsat.org [mailto:[email protected]] On Behalf Of Greg D Sent: Sunday, September 1, 2013 6:52 PM To: Amsat BB Subject: [amsat-bb] Winterization project Hi all, As I reported on the 20m Amsat Net (14.282mhz Sundays 18:00z - 19:00z) this morning, I noticed that my 2m antenna was listing slightly down-hill. Suspecting that the boom attachment screws had come loose, my project for the day was to go up on the roof and align and tighten them. The screws were a little loose. That's not why the antenna was drooping down. I discovered the real reason: Acorns. Apparently the local squirrels have been preparing for winter, such as it is around here, and had stuffed about a dozen plump acorns into the open end of the antenna boom. Besides their weight climbing out to the end, there was also the remaining weight of the acorns. So, the antenna ends have been taped over, but that's not going to prevent the squirrels from climbing out onto the antenna. Any suggestions on an effective squirrel deterrent? Greg KO6TH _______________________________________________ Sent via <mailto:[email protected]> 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> http://amsat.org/mailman/listinfo/amsat-bb

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Re: Polar Tracking LEO Satellites ... ?
by Rick Tejera 01 Sep '13

01 Sep '13

Rob, See my article in the April/May issue of the AMSAT Journal. While not motorized, I'm sure it can be easily adapted to be motorized. The basis is a simple Equatorial telescope mount. If you need a copy let me know. Rick Tejera (K7TEJ) Saguaro Astronomy Club www.saguaroastro.org Thunderbird Amateur Radio Club www.w7tbc.org -----Original Message----- From: amsat-bb-bounces(a)amsat.org [mailto:[email protected]] On Behalf Of Rob Sent: Sunday, September 01, 2013 3:38 PM To: amsat-bb(a)amsat.org Subject: [amsat-bb] Polar Tracking LEO Satellites ... ? I'm looking to put together a quick an easy portable tracking system for LEO birds .... maybe something for field day use or an ISS school contact .... Basically looking to do polar tracking with one rotor and a manual set declination angle .... Thoughts are: - rotor that can swing 180 degrees (-90,+90) - set the rotor to the half way point (0 degrees) - position the whole apparatus so that it's pointing at the azmith and elevation of the highest point on the pass - position the rotor to -90 for a west to east pass or +90 for a east to west pass - calculate the length of the pass and time the rotation so it sweeps 180 degrees in that period I'v been googling this topic till my eyes cross .... saw some data about folks trying to do polar tracking of Ao-40 a while back ... but that was a tad different considering Ao-40 is (was) in a high elliptical orbit ... Does anyone have advice ... or a link to some data .... calculations ... like how to convert az/el to something like (but not) declination/ra ???? Thanks, --> Rob, KA2PBT _______________________________________________ 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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Polar Tracking LEO Satellites ... ?
by Rob 01 Sep '13

01 Sep '13

I'm looking to put together a quick an easy portable tracking system for LEO birds .... maybe something for field day use or an ISS school contact .... Basically looking to do polar tracking with one rotor and a manual set declination angle .... Thoughts are: - rotor that can swing 180 degrees (-90,+90) - set the rotor to the half way point (0 degrees) - position the whole apparatus so that it's pointing at the azmith and elevation of the highest point on the pass - position the rotor to -90 for a west to east pass or +90 for a east to west pass - calculate the length of the pass and time the rotation so it sweeps 180 degrees in that period I'v been googling this topic till my eyes cross .... saw some data about folks trying to do polar tracking of Ao-40 a while back ... but that was a tad different considering Ao-40 is (was) in a high elliptical orbit ... Does anyone have advice ... or a link to some data .... calculations ... like how to convert az/el to something like (but not) declination/ra ???? Thanks, --> Rob, KA2PBT

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USAF Space Fence Shut Down
by B J 01 Sep '13

01 Sep '13

No signal on a website which carried its audio stream: http://www.spaceweatherradio.com/ According to: http://www.spaceweather.com/ it went silent on 0000 UTC 2013-09-01. 73s Bernhard VA6BMJ @ DO33FL

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Rolf in EN17
by Les Rayburn 01 Sep '13

01 Sep '13

Worked Rolf last night on FO-29 operating portable from EN17. Nice signal from the mobile set-up! Thanks Rolf for a new grid for me. I'll be uploading the log to LoTW tonight, and putting a card in the mail soon too. If you need EN17, you won't do better than trying for this first class operator. -- -- 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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Orbitron and WispDDE - Flipped Mode Issue
by Fabiano Moser 01 Sep '13

01 Sep '13

Hello, I am having trouble to understand how Orbitron and WispDDE works to get right Flipped passes of ISS over my QTH. Some times when ISS come from South América and cross over Europe my rotor need to work flipped, because my stop is North. Some times he do, sometimes not, then after cross 360º my rotor need to make a complete turn while is possible to go till 450º. Here is an example of one pass where rotor is NOT Flipped. http://img827.imageshack.us/img827/2755/cj0l.jpg Anyone had the same problem and/or can help me? Thanks. Best regards, Fabiano Moser CT7ABD

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Re: High orbit satellites?
by Ross Whenmouth 01 Sep '13

01 Sep '13

Hi, I think it takes about 2500m/s delta V to get from from LEO to a GTO. How feasible is it to use some type of an electric thruster (high specific impulse but low net thrust - eg a hall effect thruster or similar device) to slowly crawl up to GTO from LEO? I imagine that such a bird would charge it's batteries from solar power for most of an orbit, and would power the thruster from battery power during each perigee to slowly raise the apogee altitude. This would allow the use of a thruster with an peak electrical demand that is higher than the peak power generating capacity of the PV cells. 73 ZL2WRW Ross Whenmouth

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