December 2015 - AMSAT-BB - mailman.amsat.org

Re: [amsat-bb] Another Rotor Design - Great Fun, Easy to Build and Very Cheap
by Thomas Doyle 05 Dec '15

05 Dec '15

Thanks Phil, It is an updated version of a table top rotor I did several years ago. http://www.tomdoyle.org/satellite/SatTrackerIPoint.html The idea was to have a pointer that would point at the satellite so I knew where to point a hand-held Elk. It worked fine. This one is smaller and of course works with SatPC32. The steppers are too good a deal to pass up. To keep the size and cost down they designed a stepper with a high step angle of 5.625 degrees. They are geared down 64:1. Amazing amount of torque for such a little motor. Five of them with ULN-2003 driver boards for $16. I believe they could turn fairly large bread slicer capacitors and a rotary inductor as used in antenna tuners. A homebrew mechanical automatic antenna tuner would be an interesting project. http://www.amazon.com/USPRO%C2%AE-Stepper-28BYJ-48-4-Phase-ULN2003/dp/B00JB… 73 W9KE tom... On Fri, Dec 4, 2015 at 10:43 PM, Phil <phil_lor(a)bigpond.com> wrote: > On 05/12/15 02:31, Thomas Doyle wrote: > >> Hi, >> >> http://www.tomdoyle.org/3dPrinterRotor-1 >> > > That's really cleaver Tom. I imagine that the rotator would only handle > the lightest of aerials. > > -- > Regards, > Phil > _______________________________________________ > Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available > to all interested persons worldwide without requiring membership. Opinions > expressed > are solely those of the author, and do not reflect the official views of > AMSAT-NA. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb > -- Sent from my computer. tom ...

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(no subject)
by Gregory Beat 05 Dec '15

05 Dec '15

** Another Rotor Design - Great Fun, Easy to Build and Very Cheap ** What is a Stepper Motor? https://learn.adafruit.com/all-about-stepper-motors That Stepper Motor used by Thomas Doyle, W9KE http://www.tomdoyle.org/3dPrinterRotor-1/3DPrinterRotor-1.html can also be found at Adafruit (NYC) in either 5 or 12 Volt models. Holding Torque @ 12VDC: 250 gram-force*cm, 25 N*mm/ 3.5 oz-force*in The 12 Volt version of this same stepper motor used by W9KE can be found in the Icom IC-746 automatic tuner sub-assembly. http://www.adafruit.com/products/918 Mr. Carlson's Lab on YouTube Paul Carlson, VE7ZWZ Troubleshooting the Icom IC-746 (repairing that stepper motor) He notes that the "rotor" is a weak point in this stepper motor design. http://youtu.be/UdY6RhNOCWg === You can also use larger stepper motors, such as a NEMA 17 (also sold at Adafruit) Holding torque per phase: 2 Kg*cm, 20 N*cm/ 28 oz*in http://www.adafruit.com/product/324 w9gb Sent from iPad Air

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Another Rotor Design - Great Fun, Easy to Build and Very Cheap
by Thomas Doyle 05 Dec '15

05 Dec '15

Hi, http://www.tomdoyle.org/3dPrinterRotor-1 73 W9KE Tom Doyle

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Next Launch Attempt For Cygnus
by B J 05 Dec '15

05 Dec '15

http://www.parabolicarc.com/2015/12/04/atlas-launch-cygnus-rescheduled-satu… 73s Bernhard VA6BMJ @ DO33FL

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APRS mode on IO-86 Satellite
by Suryono Adisoemarta 04 Dec '15

04 Dec '15

This weekend IO-86 (LAPAN A2/ORARI) will be on APRS mode on the following passes: Saturday : 02.40 - 04.45 (1 orbit) Sunday: 03.02 - 05.00 (1 orbit) Freq: 145.825 MHz Path: YBSAT Next week we plan to activate voice repeater followed by APRS. 73 de Yono - YD0NXX Sent from my iPhone 5s

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Cygnus Launch Scrubbed
by B J 04 Dec '15

04 Dec '15

The weather was unfavourable. The next attempt will be made tomorrow but there's reportedly only a 30% of good conditions. 73s Bernhard VA6BMJ @ DO33FL

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Another Scrub For Cygnus
by B J 04 Dec '15

04 Dec '15

Today the reason was ground wind speeds being just above acceptable limits. 73s Bernhard VA6BMJ @ DO33FL

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Portable from EN 82 & EN 83
by jeffory broughton 04 Dec '15

04 Dec '15

This Sunday I will be operating 6 passes from the EN 82 & EN 83 line.From 9 am to 4 pm.My buddy John will be operating some of them under my call to get his feet wet! Just made a 2 hour trip to get the landowners permission ,whew! WB8RJY.JEFF jeff broughton

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WD9EWK @ Mesa AZ hamfest on Saturday (5 December 2015)
by Patrick STODDARD (WD9EWK/VA7EWK) 04 Dec '15

04 Dec '15

Hi! Just a reminder that I will have an AMSAT booth at the Superstition Amateur Radio Club's Superfest hamfest on Saturday (5 December) morning. This hamfest is at the Mesa Community College, along the east side of Dobson Road between Southern Avenue and the US-60 freeway in Mesa, Arizona. The hamfest officially opens at 7am, but I'm sure there will be people at the hamfest site an hour or two before that. It officially ends at 2pm. More information about the hamfest is available at: http://superstitionsuperfest.org/ WD9EWK will work various satellite passes from approximately 6am (1300 UTC) until either the crowd at the hamfest disappears, or the official end of the hamfest at 2pm (2100 UTC). Please call WD9EWK and be part of the on-air demonstrations. After the hamfest, my log will be uploaded to Logbook of the World, and QSL cards will be available on request (please e-mail me directly with the QSO details). The hamfest site is in grid DM43. Thanks in advance, and 73! Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK

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More On Cygnus Launch Scrub
by B J 04 Dec '15

04 Dec '15

http://www.nasaspaceflight.com/2015/12/cygnus-return-atlas-v-launch/ http://www.parabolicarc.com/2015/12/03/atlas-cygnus-launch-scrubbed-resched… http://www.spaceflightinsider.com/organizations/orbital-sciences-corp/rain-… http://spacenews.com/weather-postpones-atlas-launch-of-cygnus-cargo-spacecr… http://www.spacepolicyonline.com/news/next-u-s-cargo-spacecraft-ready-to-la… 73s Bernhard VA6BMJ @ DO33FL

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