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

HRD
by Kevin Deane 06 May '11

06 May '11

Thanks guys that was fast, I guess I could have looked a little harder...Must be getting old... Kevin

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HRD
by Kevin Deane 06 May '11

06 May '11

Does anyone know if I can copy the logbook file for HRD out out of my tower and slip it into my laptop? If so what is the name of the file, I am having troble finding it... Thanks, and am shedding 68 tears for Echo, but have not lost HOPE... Kevin KF7MYK

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Re: AO-51 troubles
by Andrew Glasbrenner 06 May '11

06 May '11

I'm not an expert here...but the memory is constantly "washed" for errors from radiation. I think the non-volatile type stuff didn't/doesn't have the read/write cycles we'd need for that. There is ROM onboard that holds the bootloader and a very stripped down OS. 73, Drew KO4MA -----Original Message----- >From: "P.H." <pholmes102(a)gmail.com> >Sent: May 6, 2011 1:28 PM >To: amsat-bb(a)amsat.org >Subject: [amsat-bb] Re: AO-51 troubles > >Ok, all is a little clearer right now! > >I wasn't aware that the sat relied on volatile memory to store the >main software. Was there a particular reason why this was chosen over >non-volatile or was it just an oversight that this issue would >eventually happen when the batteries became exhausted? > >Just curious! > >Think now is a good time to remind everyone that an extra few dollars >into the Amsat Fox fund wouldn't do any harm :-) > > >73 > >Pete >2i0VAX >

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Re: AO-51 troubles
by Andrew Glasbrenner 06 May '11

06 May '11

Hi Pete, We can actually get all of the really important files up in an optimum pass, but since all of that is stored in volatile memory, when it comes around again it's gone. AO-51 requires the software to be running to do much of anything, as all the audio and control is run through the IHU. Even if we could upload everything in one pass, there is nothing to keep it from resetting right away during the next eclipse. We've not given up, but it's looking really grim right now. Let me point out that AMSAT-NA has been learning from our past (and present) experiences. The current design for Fox, seen as a replacement for AO-51 by many, includes what the team has been referring to as "zombiesat" mode. In this mode, Fox will operate without the IHU, and maybe even without the batteries while illuminated. We would still retain the ability to command the transmitter off if need be. As I understand it, the design also includes non-volatile memory for some systems, which would really be useful right now on 51. 73, Drew KO4MA AMSAT-NA VP Operations -----Original Message----- >From: "P.H." <pholmes102(a)gmail.com> >Sent: May 6, 2011 12:46 PM >To: amsat-bb(a)amsat.org >Subject: [amsat-bb] Re: AO-51 troubles > >Hi Drew & all, > >I'm not 100% sure how the software uploads take place, however I have >a suggestion. > >Would there be any benefit having one uplink station on the west coast >and another on the East coast, purely to allow the complete upload to >take place before an eclipse? > >Perhaps the users of AO-51 would donate to a road-trip fund to send >one of the command stations /portable to a location of benefit to >assist ? > >Just trying to think outside the box :-) > >good luck with the uploads, > >73 > >Pete > >2i0VAX

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AO-51 troubles
by Andrew Glasbrenner 06 May '11

06 May '11

All, We are having a difficult time trying to restore AO-51 to operation. Currently, the satellite will not retain the upload of the flight software across eclipse. The batteries are in very poor condition. We have a few more things to try, but with eclipses peaking around July at ~27 minutes, the long term situation is grim. There is a brief period around November where eclipses are as short as 16 minutes, but past that it is a long climb to 30 minutes or longer eclipses for many years. We have no expected "return to service" date. If you have 9k6 digital capability, you can listen in on our attempts at recovery on 435.150 on many passes over the US. Please support AMSAT-NA and the other AMSAT groups around the world, and help us get new satellites into orbit. Projects like Fox, FunCube, P3E, and Kiwisat need your financial support to keep our amateur satellite fleet flying. 73, Drew KO4MA AMSAT-NA VP Operations

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Re: Cables for small satellites
by Graham Shirville 05 May '11

05 May '11

Hi All, Many thanks to the kind experts who kindly sent us information in repect to this enquiry a couple of weeks ago. For FUNcube we have determined that the best coax for our purposes is RG178. The following reasons: we are only concerned with VHF and UHF signals flight heritage small diameter small minimum bend radius suitability for a variety of connectors - we are using MCX, MMCX and SSMCX connectors on different boards (for good reasons of course) Lessons learnt and advice received included: RG178 should not be used outside a spacecraft where it might be exposed to UV The cables will need retaining in some way to resist viabration during launch - glue to board or "tie" to structure. The connectors will also need to be glued together before flight It may be peferable/more reliable to solder cables directly to boards for flight models. All connectors are designed for a limited number of insertions. Therefore "saver" cable/connector assemblies should be used during most of the testing/verification programme. There is a range of extra flexible semi-rigid cables available. (Thats sounds confused) Like all COTS items used in space, the minimum bend radius rule of thumb - 6 times the outer diameter - should be derated if possible. again thanks an apologies for the delay in getting the results back out:) 73 Graham G3VZV A simple question this time! What is the best coax cable to use in a cubesat? Size, flexibility/min radius, existing space heritage, ease of applying connectors are our main design drivers - we are only using UHF and VHF so losses are not going to be too much of a problem hopefully.. many thanks in advance 73 Graham G3VZV

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Funnies
by Kevin Deane 05 May '11

05 May '11

Since Ham Radio cartoon funnies seem to be so hard to come by, I have been making my own. I was hoping I could find out from you guy's what was the OLDEST and BEST sat you all got to use so I could make them more interesting...Basically lookin for the oldtimers fav, something before my time if you will. I know Amsat has good info on all of them, just do not know the right one or one's to pick for my project. I have had good feedback on them so far, I thought I might circulate them publicly seeing how postage would get a little expensive... Kevin KF7MYK

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13 Original Colonies Special Event help needed
by Dave Webb KB1PVH 05 May '11

05 May '11

I am still looking for operators for CT, NH, NJ for the 13 Original Colonies Special Event. If anyone wants to participate send me an email. http://www.13colonies.info/ Dave - KB1PVH Sent from my Verizon Wireless DROID X

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Portable satellite antenna
by Alexander Sack 05 May '11

05 May '11

AMSAT-BB: I am a relatively new ham (1.5 months) and I have caught the satellite bug. I own a Kenwood TH-D72A which from reading this list and some others is a great little HT to operate satellites. The issue is an antenna. I live in an antenna restricted area so I am not sure what to do. I have read about the Arrow Antenna: http://www.arrowantennas.com/arrowii/146-437.html My goal is to work minimally the ISS! :-) Can folks suggest a portable setup that could work with my HT? Or are my expectations too high? 73 -aps (KC2ZSX)

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AmSat hey
by gregory.beat＠comcast.net 05 May '11

05 May '11

AmSat, talk to you later http://r2.bit.ly/mrj9iK --- I want meadows red in tone and trees painted in blue. Nature has no imagination. -- Charlse Baudelaire osama bin laden is dead

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