November 2009 - AMSAT-BB - mailman.amsat.org

Speaking of Icom release dates...
by Michael Tondee 20 Nov '09

20 Nov '09

What about the new Kenwood? Anyone know if it will be sat capable? I hope to have enough money after the first of the year to purchase a new radio. Unfortunately, I think both the new Icom and Kenwood rigs will be out of my reach. I've heard rumors of 3K + for the Icom price. . I liked the TS-2000X I had and was hoping to get another new one before production is discontinued. Michael, W4HIJ

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Intelsat is advertising for Geosynchronous Hosted Payloads
by Daniel Schultz 19 Nov '09

19 Nov '09

Intelsat is running banner ads on Science Magazine's web site, offering "Hosted Payloads" on geosynchronous satellites. Check it out at http://www.spacedelivered.com/view/ Dan Schultz N8FGV

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Re: Satellite Thermal Lesson
by Robert Bruninga 19 Nov '09

19 Nov '09

> Subject: Re: [amsat-bb] Re: Satellite Thermal Lesson > > Fascinating report, Bob - thanks for sharing... > I recently bought a cheap IR thermometer (gave into a > long-standing state of curiosity) and had great fun > with it; can't wait to do some more testing, but > lots of fun walking around pointing at things > in the environment. But if you read the docs, the display from such an IR thermometer is completely meaningless unless you know the EMISSIVITY of what you are pointing at... Now the good news is that MOST things have a reasonablly good emissivity, such as BLACMK and WHITE and Fingerprints etc... Remember, even my fingerprints changed the emissivity of my aluminum from about 4% all the way up to near 90% like black and everything else. But point that thermometer at CLEAN aluminum and the reading will be meaningless for TWO reasons: 1) If it is clean, it will see hardly any IR from the aluminum and so "it should read a real low temperature"... 2) But it WONT! The reason is, that ALUMINUM is also a great REFLECTOR of IR! So therefore your IR thermometer will not even see the alluminum plate anyway, because all it will see is what it sees reflected in the aluminum. You can prove this to your self by holding a sheet of aluminum as if it was a mirror. Point is so y our IR gun see's your body in its reflection and you will see your body temperature. Point the reflection to somethig cold, and it will read the cold temperature. So again, those IR thermometers are only as good as the knowledge of the person using them. That's why those "window" snake-oil salesmen can come out and show you all the "leaks" and lost heat in your home, and sell you thousands of $$$ of new windows, because they either 1) don't have a clue how their instruments work, or 2) They do know, but they use the missleading display to fool the gullible. Thanks for the reminder about those IR thermometers. Someone in our department got some and was running around doing all kinds of measurements... Then we showed him how his measurements didn't mean a thing unless he knew the emissivity of what he was shooting at... Sure pulled the rug out from under him. But again. Almost everything around you has a high emissivity... But if he doesn't know what does and what doesn't, then he is just messing around... And should not use those numbers for anything valuable... Bob, WB4APR

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IC-910 mic connector
by Bob- W7LRD 19 Nov '09

19 Nov '09

For you 910 owners I am configuring a sequencer for my IC-910. On the mic connector, what is the +8Vdc 10ma on pin 2 used for? I am tapping into the PTT for triggering the sequencer and just trying to figure it all out. Thanks 73 Bob W7LRD Washington State AMSAT area coordinator

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Thanks for 3 new grids on AO-27 this afternoon!
by Patrick STODDARD (WD9EWK/VA7EWK) 19 Nov '09

19 Nov '09

Hi! Thanks to John W6ZKH, Alvaro XE2AT, and Ismael XE1AY for 3 new grids in the log during an AO-27 pass around 2043 UTC this afternoon. As "advertised", John and Alvaro were on from unusual spots - W6ZKH from DM07 in California, XE2AT from EK19 in Veracruz on the Mexican Gulf coast. XE1AY was also in there from DL91 in central Mexico, another new one for the log. Alvaro - it is nice to see you operate from different parts of Mexico once again. It's been a while. :-) 73! Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/

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AO-51 back to 9k6 PBBS and telemetry
by Andrew Glasbrenner 19 Nov '09

19 Nov '09

Due to a combination of meeting some of our objectives early and having issues with others, we have switched from 38k4 to 9k6 for the last day of this scheduled mode. We might be experiencing some desense issues on the L uplink with the 38k4, so for the next 24 hours we'd like to encourage any L/U 9k6 capable stations to attempt to access the BBS and let us know if you are successful. Power is at 2.05 watts, so the downlink is strong. 73, Drew KO4MA AMSAT VP Operations

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Arrow Antenna - Mod II
by Clint Bradford 18 Nov '09

18 Nov '09

I just posted photos of another "mod" performed to my Arrow Satellite Antenna: the addition of an HT tray. Helps with "counter-balancing." Use the PHOTOS link at the top of ... http://www.work-sat.com Clint Bradford, K6LCS 909-241-7666

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Re: PocketSat3 for iPhone, iPod touch
by Clint Bradford 18 Nov '09

18 Nov '09

>> ... Unfortunately the $1.99 version is only good for 40 fixed sats ... The two-buck app lets you know if the program runs properly on your particular setup. Again, I have tried six sat tracking apps for my new 32GB iPod touch - and PocketSat3 if the finest of the bunch. Clint Bradford, K6LCS http://www.work-sat.com

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Satellite Thermal Lesson
by Robert Bruninga 18 Nov '09

18 Nov '09

Lesson learned on Satellite Thermal. For years, we have been trying to demonstrate to students the extreme differences in Temperature of a satellite based simply on its color. In space, far from earth, here is what you should get for three identical satellites: Black will be about +55 deg F White will be about -60 deg F Aluminum will be about +225 deg F (from memory anyway)... But we have never been able to see the extreme temperature of the aluminum in our vacuum chamber. Of course, we are not using a SUN, but an incandescent lamp which has 95% of its radiation as heat and only 5% as light, so we attribtuted our wishy-washy results as due to the lack of real solar spectrum. This year, we finally have a Tvac chamber that has a liguid nitrogen cold plate so we can actually better simulate the blackness (and cold) of space.. Again, same result. Aluminum was about the same as black. This was a frustrating result from this new chamber. Then I noticed the fingerprints on the aluminum. I cleaned the aluminum with a swab of alcohol to eliminate all the surface contaminants, and fingerprints and re-did the test... BINGO. Now the temperature of the aluminum goes up and off scale HOT, way way different from the black or White. And now the WHITE also goes colder.. So just the thinneest innvisible layer of surface contamination completely changed the thermal emissivity of the Aluminum. And we all know this anyway, since "low-E" coatings of glass and other materials is now so common. It is only the outer surface of molecules that set the absorbtivity and emissivity... And the differnce between Black and Aluminum is 30-to-1 (if the aluminum is clean)... That's why we wrap baked potatos in Aluminum foil! (don't use greasy hands)... Of course we always clean our actual spacecraft to clean-room conditions before flight, so this does not impact our on-orbit results, but it sure does make a difference in the lab when we are demonstrating absorbtivity and emissivity in the chamber with samples handled by the students! When I get a chance, Ill post the results... Bob, WB4APR

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PocketSat, RIP ???
by Clint Bradford 18 Nov '09

18 Nov '09

Unfortunately, I heard "one of us" report last week that "PocketSat isn't really popular any more, with the demise of the Palm computing platform ... " That's woefully incorrect on many fronts. Palm users are plentiful, and Jim is still supporting us. PocketSat+ is still the best Palm-platform satellite tracking software available, IMHO. Support still at ... http://www.bigfattail.com But Jim has not let his programming skills stagnate. We now have PocketSat3 for the Apple iPhone and iPod touch devices. It provides gorgeous screen graphics for our passes. Available in the Apple Store. Docs and support at Jim's new site at ... http://www.pocketsat.com/ It works marvelously on my new 32GB iPod touch. AMSAT's keps are one of the four default sets for painless download. Recently added is a "View Constellation" mode - which overlays your view of the heavens on a sat pass. There are several "satellite trackers" in the Apple Store ... from free to $.099 to a few bucks. I have tried five others. NONE of them come close to the feature set, ease of use, and product support that one receives with PocketSat3. Clint Bradford, K6LCS http://www.work-sat.com 909-241-7666

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