April 2014 - AMSAT-BB - mailman.amsat.org

DSTAR Satellite users net weather permitting
by wa4hfn＠comcast.net 03 Apr '14

03 Apr '14

Hi All D Star Satellite users net tonight 0100 utc on REF 60 B Thanks WA4HFN em55 Damon

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Re: Ferrite RFI filters and Traps? (yes!)
by Robert Bruninga 03 Apr '14

03 Apr '14

>> I cut the RFI Ferrite blobs off of all trash Keyboards and stuff. >> These are great Ferrite devices. >> But what are they best for? > Check out this article from Chuck Councilman W1HIS: > http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf Wow, a long one, but on page 24 of 42 I learned a great technique. He says, simply put a turn or two on any ferrite core and hook it to an antenna analyzer. Then look at the impedance over frequency. At DC (or your lowest frequency) the impedance should be very low (and 90 degrees) Meaning the R is very low and the +jX is very high. Keep going up in frequency to where the R and jX terms are equal. That is where the Q is now 1 and the ferrite is starting to get quite lousy. He also said that as you double frequency, the R part of the impedance should also double. When you get to the frequencies where a doubling of frequency no longer doubles R, then you are starting to get into frequencies where this core is less effective. That is exactly the kind of rule-of-thumb advice I was looking for! Now I know what to do with all these cores! Bob, WB4aPR

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INVADER is "Cubesat OSCAR-77 (CO-77)"
by Akihiro Kubota 02 Apr '14

02 Apr '14

Please note that ARTSAT1:INVADER (call:ZQ1ZKK, norad:39577U) has got its OSCAR number: Cubesat OSCAR-77 (CO-77) was issued to INVADER on April 2, 2014. We would like to express best thanks to AMSAT-NA and all of you. ARTSAT Web Page: http://artsat.jp ARTSAT Facebook Page: http://www.facebook.com/artsat Akihiro Kubota ARTSAT Project Leader ===== - Message from Mr. Bill Tynan, W3XO (2014/04/02) Professor Kubota-san: Thank you for your reply. >From what I can determine, the ARTSAT Project, INVADER satellite meets all of the qualifications necessary to receive an OSCAR number. In accordance with your e-mail response, I will use Cubesat in the designation for this satellite. I therefore designate the ARTSAT Project INVADER satellite, Cubesat OSCAR-77 or CO-77. Thus CO-77 joins the earlier Japanese cubesats such as XI-IX(CO-57), XI-V(CO-58), Cute-I(CO-55), SEEDS-II(CO-66). Congratulations to you and the entire ARTSAT team for the launch and operation of Amateur Radio satellite, CO-77. May its mission be a successful one. 73, William (Bill) Tynan, W3XO AMSAT-NA OSCAR Number Administrator =====

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OFCOM VHF Consultation Document
by David Barber 02 Apr '14

02 Apr '14

Link to OFCOM VHF consultation - Includes potential expansion of UK 2m. http://tinyurl.com/o3tdohe David Barber G8OQW ********

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Joe Walsh on Ham Nation Tonight!
by Clint Bradford 02 Apr '14

02 Apr '14

TONIGHT - Wednesday night, Joe Walsh WB6ACU is going to be on the Ham Nation show with us. Will be a blockbuster show with several in- studio guests. Joe will be introducing a new host that is joining the show. That is 6PM PDT / 8PM CDT, Wed April 2, 2014. Go top http://www.twit.tv and click on WATCH LIVE! And join the discussion room! Clint PS Before ANYONE asks, "Why post this here, Clint???" - Well, if anyone has ever heard Joe perform, they'd agree that his work is space-worthy and out of this world ... If that isn't good enough, just know that Ham Nation has been very supportive of "working the satellites" - just view episodes 11 and 46, for starters ...

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Ferrite RFI filters and Traps?
by Robert Bruninga 02 Apr '14

02 Apr '14

I cut the RFI Ferrite blobs off of all trash Keyboards and stuff. These are great Ferrite devices. But what are they best for? IE, 1) are they intentionally lossy or are they High Q? and 2) What is their Optimium Frequency range (all ferrite torroid coil forms come in a variety of materials optimized for different frequency ranges. There is a big difference between the ferrite in a switching power supply (100 kHz) and something usable at VHF or UHF. I assume these ferrite tubes are probably optimized for digital and power supply hash only and so probably only suitable for use at HF, but probably not at VHF and UHF? And what is their Q? Can they be used for making high Q circuits? Today I am using some on the outside of a coax right at the edge of a cubesat to decouple the coax going to the network analyzer from the RF enveolope of the spaceframe for antenna tuning. So today's question had to do with their ability to serve as a high loss filter at UHF. But we may as well list all we know about these ferrites for other applications? p.s. My method for getting them out of the molded rubber is to cut the cable right clean at the ends. Then use a large drill (1/4") to drill out all the internal wires. Then use a hacksaw to cut off one end of the rubber as close as possible to the ferrite but without cutting it. Then pealing back the rubber or nibbling at it with a pair of dikes.... Got a hobby drawer full now. Bob, WB4APR

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Re: Joe Walsh on Ham Nation Tonight!
by Jeff Yanko 02 Apr '14

02 Apr '14

Can't get any better than this. Life's Been Good. Jeff WB3JFS ----- Original Message ----- From: "Clint Bradford" <clintbrad4d(a)earthlink.net> To: <amsat-bb(a)amsat.org> Sent: Wednesday, April 02, 2014 2:14 PM Subject: [amsat-bb] Joe Walsh on Ham Nation Tonight! > TONIGHT - Wednesday night, Joe Walsh WB6ACU is going to be on the Ham > Nation show with us. > > Will be a blockbuster show with several in- studio guests. Joe will be > introducing a new host > that is joining the show. > > That is 6PM PDT / 8PM CDT, Wed April 2, 2014. > > Go top http://www.twit.tv and click on WATCH LIVE! And join the discussion > room! > > Clint > > PS Before ANYONE asks, "Why post this here, Clint???" - Well, if anyone > has ever heard Joe perform, > they'd agree that his work is space-worthy and out of this world ... If > that isn't good enough, just > know that Ham Nation has been very supportive of "working the > satellites" - just view episodes 11 > and 46, for starters ... > > _______________________________________________ > 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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13 colonies sat ops
by Jeff Griffin 02 Apr '14

02 Apr '14

The yearly 13 colonies event up to now also included a special separate event for satellite operations. http://www.13colonies.info/Satellites.htm This included a 13 colonies sweep satellite certificate. This is one of the few awards still offered to satellite operators that has international recognition. I can vividly remember the last time, 2 years ago giving satellite operators the sweep from DE, most notably our Cuban friend Hector. Last year we only had sat operations from 11 of the 13 states. I just did an informal survey of the states that participated last year and find that only 7 states will be active this year. The consensus among the 13 colonies group is that this isn't going to work. We need to get all 13 colonies involved. The states we need to get operations going from are. CT DE MD NC PA RI If we get the rest I will once again make the trip to DE to assure anyone who wants the sweep. I know there has to be at least one good sat op in all of these states, let's not let this die. Let me know off list if you're interested in getting involved, I will do all I can to assist... 73 Jeff kb2m

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MO-76 wins PICAXE project of the month
by Howie DeFelice 02 Apr '14

02 Apr '14

The MO-76 $50sat team is pleased to announce that $50sat was chosen as Project of the Month by Rev-Ed, the makers of the PICAXE processor used in MO-76. http://www.picaxe.com/Project-Gallery/50SAT/ Howie AB2S

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Another theory regarding the Fermi Paradox
by Daniel Schultz 02 Apr '14

02 Apr '14

The following paper "A Necro-Biological Explanation for the Fermi Paradox" appeared on the physics preprint server this morning: http://arxiv.org/abs/1403.8146 The Fermi Paradox asks, if there are other intelligent civilizations in the galaxy, why have they not come to visit us? I have no comment regarding the date of publication. Dan Schultz

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