June 2010 - AMSAT-BB - mailman.amsat.org

QSLs sent
by Bob DeVarney W1ICW 06 Jun '10

06 Jun '10

To all who have sent me QSLs over the last several years. I am finally getting back in to the hobby and sat down last night and filled out a bunch of cards. S if anyone was waiting for VT on the sats from either W1ICW or WE1U, your patience is about to be rewarded. I am ashamed to admit some of the cards had 34 cent stamps on the SASEs... that's how far behind I had gotten. Again, my apologies and 73, Bob W1ICW

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Re HELIX REFLECTOR?
by Clare Fowler 06 Jun '10

06 Jun '10

To add to the discussion the July/Aug 2007 Amsat Journal has an article covering some gain comparisonmeasurements I made between four 13 turn (2.88 wavelengths) 13cm antennas with different square solid aluminum reflectors. The sizes were 0.56 wavelengths, 0.84 wavelengths, 1.0 wavelength and 1.4 wavelengths. There was no difference between the 0.84, 1.0 and 1.4 wavelengths but the antenna with the0.56 wavelength reflector had 1.5 db less gain. However for my 70cm helix antennas I followed the Satellite Handbook minimum size of 0.6 wavelengthsor slightly over 16 inches. I used 1/2 inch hardware cloth mesh to keep the weight and windloading down. These antennas have performed well however it appears that they would be a bit better with a somewhat larger reflector. A brief description and picture of the 70 cm reflector is in the November/December 2005 Amsat Journal article on The Development of a Quarter Wave Match for helical antennas. Clare VE3NPC >> Hi All: >> I am rebuilding a 440 MHZ Helix that I built several years ago . It >> worked very well, but I would like to reduce the size of the reflector to >> a more manageable size than I had before. The only reference to reflector >> size I can find is, "minimum 20" ". I may be looking in the wrong places. >> I would appreciate it, if someone would steer me in the right direction. >> Thanks, >> Pete, K1HZU

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WD9EWK on the move tomorrow to DM56
by Patrick STODDARD 05 Jun '10

05 Jun '10

Hi! Thanks to all the stations that worked me today, at the White Mountain Hamfest in Show Low and later in the day at DM44xj/DM54aj north of Show Low. WD9EWK logged 41 QSOs at the hamfest (including an amazing 12 QSOs on one AO7 pass around 1400 UTC!), followed by 47 more at the grid boundary. I hope to be up at DM56 Sunday morning for the 1620 UTC SO50 pass. I may be able to park on the DM55/DM56 line, but the primary goal for the day is DM56. I'll work passes on SO50, VO52, HO68, AO27, plus an AO51 pass just before 2300 UTC. Tomorrow will be a busy driving day - about 3 hours from here up to DM56, then 5 hours or so from DM56 back home. With the long drive home, I can't stay in DM56 for the passes after 2300 UTC nor do I plan to stop for any passes that I could work in the evening. I hope to work a bunch of you tomorrow from one of the rarely-heard grids in Arizona. 73! Patrick WD9EWK/VA7EWK - Pinetop-Lakeside, Arizona http://www.wd9ewk.net/

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AMSAT 2010 Space Symposium at Elk Grove Village, IL
by Mark Thompson 05 Jun '10

05 Jun '10

http://forums.qrz.com/showthread.php?t=251141 AMSAT Announces 2010 Space Symposium ________________________________ AMSAT announces the 2010 Space Symposium and Annual Meeting will be held on Friday, October 8 through Sunday, October 10. This year we have selected the Chicago/Elk Grove Holiday Inn which is near O'Hare Airport for the event. This is the same hotel that recently has hosted the Central States VHF Conference, TAPR and W9DXCC events. All Amateur Radio Operators interested in space communications are invited to participate in the Symposium offerings including: * Space Symposium with Amateur Satellite Presentations * Operating Techniques, News, & Plans from the Amateur Satellite World * Board of Directors Meeting open to AMSAT members * Meet Board Members and Officers * Annual General Membership Meeting * Annual Banquet—Keynote Speaker and Door Prizes * President's Club Reception * Area Coordinator's BreakfastThe Chicago/Elk Grove Holiday Inn is located at 1000 Busse Road, Elk Grove, IL (near O’Hare Airport with free hourly shuttles). The room rate and reservation information will be announced shortly. Watch the AMSAT Symposium Page www.amsat.org/amsat-new/symposium/2010/index.php for more news as it becomes available. 2010 Space Symposium First Call for Papers, Posters & Presentations This is the first call for papers for the 2010 AMSAT Space Symposium and Annual Meeting to be held October 8 - 10 at the Chicago/Elk Grove Holiday Inn near O'Hare Airport. The Symposium Committee invites proposals for: * Papers for publication in the Proceedings * Symposium Presentations * Poster Presentations * Equipment and Operating DemonstrationsThese can be on any topic of interest to the amateur satellite community. We request a tentative title of your paper/presentation as soon as possible, with final copy submitted by September 1, 2010 for inclusion in the printed proceedings. Abstracts and papers should be sent via e-mail to k9jkm(a)amsat.org The 2010 Symposium Author's Guide can be found at www.amsat.org/amsat-new/images/fck_images/AuthorGuide2010%283%29.txt

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Fw: WD9EWK @ DM44xj/DM54aj now
by i8cvs 05 Jun '10

05 Jun '10

----- Original Message ----- From: "Patrick STODDARD" <amsat-bb(a)wd9ewk.net> To: <amsat-bb(a)amsat.org> Sent: Sunday, June 06, 2010 12:35 AM Subject: [amsat-bb] WD9EWK @ DM44xj/DM54aj now Hi! I found a spot on the DM44/DM54 line for the passes starting with the AO7 pass at 2256 UTC through at least the SO50 pass at 0206 UTC. Hope to work you from here. 73! Patrick WD9EWK/VA7EWK - north of Show Low, Arizona http://www.wd9ewk.net/

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HELIX REFLECTOR
by i8cvs 05 Jun '10

05 Jun '10

----- Original Message ----- From: "Pete Norris, K1HZU" <k1hzu(a)yahoo.com> To: <amsat-bb(a)amsat.org> Sent: Friday, June 04, 2010 2:51 AM Subject: [amsat-bb] HELIX REFLECTOR? > Hi All: > I am rebuilding a 440 MHZ Helix that I built several years ago . It worked > very well, but I would like to reduce the size of the reflector to a more > manageable size than I had before. The only reference to reflector size I > can find is, "minimum 20" ". I may be looking in the wrong places. I would > appreciate it, if someone would steer me in the right direction. > Thanks, > Pete, K1HZU Hi Pete, K1HZU My 15 turns RHCP 70 cm Helix Antenna was built at first with a round aluminum sheet perforated reflector with a diameter of 460 mm ( 0.67 wavelenght) and it worked very well but after enlarging the diameter of reflector to 690 mm (about 1 wavelenght) overlapping to it a perforated aluminum mesh I realized that the gain increases by about 2 dB and the front to back ratio was much better than before. The Helix is made with a non annealed wiredrawn aluminum rod 8 mm in diameter and the boom is made with a very hard plastic pipe 42 mm outside diameter and 31 mm inside diameter originally used for hight pressure oil ducts. Following "ANTENNAS" from John Kraus the lenght of a turn has been made 1 wavelenght long into free space and the pitch angle between turns is about 13.8 degrees while the calculated half-power beam width is about 28 degrees. The matching system between the 150 ohm impedance at the feed point and a 50 ohm coax cable is made using a 1/4 electrical wavelenght impedance transformer with Zo = 86 ohm made with two coaxial tubing. For better performance and not to distort the pattern the antenna is fastened to the rear of reflector and the weight is balanced with a counterweight made with few lead disks. The picture of the above 15 turns helix antenna is visible at i8CVS in QRZ.com I have built two Helix Antennas the first one is a 10 turns with 0.67 wavelenght round reflector used beginning from OSCAR-7 to actually FO-29 and HO-68 and it works very well. The second one is a 15 turns helix with a 1 wavelenght in diameter round reflector and it was used for the uplink from OSCAR-10 to AO40 as can be seen at i8CVS in QRZ.com but unfortunately I cannot use it for LEO satellites because the AZ/EL mount is slow because it was designed for HEO satellites and this is why I pull for P3E ! If someone is interested to built the above antenna for 10 or 15 turns I can send a zipped file with all the electrical and mechanical sized drawings of it. Best 73" de i8CVS Domenico

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HELIX REFLECTOR?
by Pete Norris, K1HZU 05 Jun '10

05 Jun '10

Hi All: I am rebuilding a 440 MHZ Helix that I built several years ago . It worked very well, but I would like to reduce the size of the reflector to a more manageable size than I had before. The only reference to reflector size I can find is, "minimum 20" ". I may be looking in the wrong places. I would appreciate it, if someone would steer me in the right direction. Thanks, Pete, K1HZU

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WD9EWK @ DM44xj/DM54aj now
by Patrick STODDARD 05 Jun '10

05 Jun '10

Hi! I found a spot on the DM44/DM54 line for the passes starting with the AO7 pass at 2256 UTC through at least the SO50 pass at 0206 UTC. Hope to work you from here. 73! Patrick WD9EWK/VA7EWK - north of Show Low, Arizona http://www.wd9ewk.net/

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Falcon 9 video - moving early?
by vk1pe.peter 05 Jun '10

05 Jun '10

I think that my eyes are not deceiving me. See http://www.youtube.com/watch?v=sP5gykvTBpM or http://bit.ly/dx9Vot. Falcon 9 appears to move at about T -3s. The count is still running towards zero in the video, and the "call" seems to be between 4 and 3. What do others think? Also, were the umbilicals meant to "tear away" (as it moved) or "drop away" (before it moved)? Peter VK1PE

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WD9EWK - midday Saturday
by Patrick STODDARD 05 Jun '10

05 Jun '10

Hi! This has been a good hamfest here in Show Low AZ. The morning started with 12 QSOs on AO7 around 1400 UTC! More on VO52 and SO50 later. Thanks to K8YSE and KD8CAO in Michigan for the QSOs, as well as N5AFV operating as KK5W in Texas. I will be on SO50 @ 1913 UTC followed by AO27 @ 1937 UTC to wrap up the hamfest demos. Thanks to WA8SME, N5AFV as KK5W, and AA5CK for talking with a Boy Scout that stopped by during the 1730 UTC SO50 pass! Several Scouts were able to satisfy several requirements toward th Radio Merit Badge, including the Scout who was on the mic. My first pass from DM54 (or possibly the DM44/DM54 boundary) will be a shallow AO7 pass at 2256 UTC. Hope to put more in the log then, to go with 33 QSOs wlready logged at the hamfest with two passes remaining. 73! Patrick WD9EWK/VA7EWK - Show Low, Arizona http://www.wd9ewk.net/

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