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

Third Time Lucky For Antares
by B J 21 Apr '13

21 Apr '13

The launch was smooth and the payload is now in orbit. 73s Bernhard VA6BMJ @ DO33FL

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Icom IC-910 For Sale
by Dave Webb KB1PVH 21 Apr '13

21 Apr '13

I'm selling my IC-910 with one UT-106 DSP unit and UX-910 1296 MHz. $1475 shipped USA only. Contact me direct. Dave-KB1PVH Sent from my Verizon Wireless Droid RAZR

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ppod sep Antares!
by Lizeth Norman 21 Apr '13

21 Apr '13

Let the fun begin!

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'Bring Your Own Board’ CubeSat Workshop July 19
by M5AKA 21 Apr '13

21 Apr '13

Surrey Space Centre (SSC) and AMSAT-UK invite anyone with CubeSat equipment to a ‘Bring Your Own Board’ (BYOB) workshop being held at the Surrey Space Centre, Guildford, UK on Friday, July 19. Admittance to the Workshop is free, see http://amsat-uk.org/2013/04/21/bring-your-own-board-cubesat-workshop/ The AMSAT-UK International Space Colloquium takes place Saturday/Sunday July 20/21 at the Holiday Inn Hotel, Guildford, further details at http://amsat-uk.org/colloquium/colloquium-2013/ 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: Mount an Arrow on rotator with 2m vertical orhorizontal
by i8cvs 21 Apr '13

21 Apr '13

Hi Douglas, Using two identical 50 ohm coax lenght you can't transform each 50 ohm antenna impedance into 100 ohm but if you connect both 50 ohm coax cables to a T connector than the resulting impedance at the common output of the T connector will be 25 ohm i.e. two 50 ohm impedances in parallel and your radio will see a VSWR of 50/25 = 2 and this is the reason it will not work ! BTW if you connect the above 25 ohm impedance to the input of a 1/4 electrical wavelenght long coax cable of 36 ohm impedance than at the output of it you will get an impedance of 36^2 / 25 = 52 ohm toward the main feed line with a good VSWR of about 1 in TX and RX To build a 1/4 electrical wavelengt long of a transmission line of 36 ohm impedance you can connect in parallel two 1/4 electrical wavelenght of 75 ohm coax cable like RG-59 or RG-11 i.e. 34,13 centimeters or 13,38 inches long for 145 MHz BTW in this situation if both antennas are mounted in parallel one Vertical and the other one Horizontal and if the elements are mounted on the same plain with respect to the space than the resulting polarization of the radiated field can be at 45 degrees like \ or at 135 degrees like / depending at wich side of the dipoles the inner conductors of the 50 ohm feed lines are connected. 73" de i8CVS Domenico ----- Original Message ----- From: "Douglas Phelps" <dphelps1(a)ameritech.net> To: "R.T.Liddy" <k8bl(a)ameritech.net>; <amsat-bb(a)amsat.org> Sent: Tuesday, April 16, 2013 8:31 PM Subject: [amsat-bb] Re: Mount an Arrow on rotator with 2m vertical orhorizontal > Any reason why, using identical coax lengths, you could not transform the > impedance to 100 ohms and then use a T connector to sum both antenna > signals and achieve 50 ohms to the radio? I know Transmit power will be > 3 dB down at either antenna but is there any reason it will not work? > Any antenna gurus out there? >

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Antares Launch Attempt Scrubbed
by B J 20 Apr '13

20 Apr '13

http://www.nasaspaceflight.com/2013/04/orbital-antares-debut-launch-attempt/ http://spaceflightnow.com/antares/demo/status.html Next attempt will apparently be tomorrow. 73s Bernhard VA6BMJ @ DO33FL

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Bringing the F-1 engine back to life
by W4ART Arthur Feller 20 Apr '13

20 Apr '13

http://arstechnica.com/science/2013/04/how-nasa-brought-the-monstrous-f-1-m…

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G-5500 and ST-3 interface for sale
by John / NS1Z 20 Apr '13

20 Apr '13

Just a quick note: My G-5500 Yaesu rotor and ST-3 interface are for sale. Very good condition and working perfectly. If you live close to 34488 (Ocala/Silver Springs FL) I have the fiberglas cross boom I will include at no charge. Asking $650 for all.

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Soyuz CubeSat Launch April 19
by M5AKA 19 Apr '13

19 Apr '13

I believe the launch date for the Soyuz is still April 19 at 1000 UT. As with all launches things can change at the last minute. Info on the satellites and predicted TLE for BEESAT-2: http://amsat-uk.org/2013/04/17/soyuz-cubesat-launch/ ---- Trevor M5AKA AMSAT-UK http://www.amsat-uk.org/ Join or Renew your AMSAT-UK membership at http://shop.amsat.org.uk/shop/category_7/Membership-of-AMSAT-UK.html ----

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OSSI-1 and other CubeSats launched
by M5AKA 19 Apr '13

19 Apr '13

See http://amsat-uk.org/2013/04/19/ossi-1-amateur-radio-cubesat-launched/ 73 Trevor M5AKA

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