July 2012 - AMSAT-BB - mailman.amsat.org

CO6CBF/p FL02
by Hector Luis Martinez Sis 18 Jul '12

18 Jul '12

Hello there! If anyone still needs FL02, I will be in a work trip to Villa Clara province and I will try to operate on the 1939utc AO-27 pass. 73! Hector, CO6CBF *************************************** Genius is one per cent inspiration, and ninety-nine per cent perspiration. -- Thomas A. Edison *************************************** --- Consulte la Enciclopedia Colaborativa Cubana http://www.ecured.cu/

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Herringbone Log Periodic Antenna
by Joe Lowenthal 18 Jul '12

18 Jul '12

In June there was an email about the Herringbone Log Periodic's which were used at Dayton. Can someone give me that link? Thanks &73, Joe WA4OVO EM55

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CG3B Special Event on Satellites
by John Papay 18 Jul '12

18 Jul '12

A station in FN03 using the callsign CG3B was worked on the 0020z SO-50 pass on 18 July. It is a special event callsign commemorating 200 years of friendship between Canada and the US (after the War of 1812). The operator was unknown. QRZ.com indicates that the callsign will be used during the entire month of July. The QSL card will be mailed using a special issue 1812 Canadian stamp. QSL to VE3FOI. The sponsor is the Niagara Peninsula ARC. 73, John K8YSE

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XE3DX on EL60 Today
by David Maciel 17 Jul '12

17 Jul '12

EL60 will work from now on AO27 Pass XE for 14:58, 19:58 UTC ... from the Mexican Caribbean. David Maciel

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WTB a "beater" FT-817 for sat rx
by Clayton Coleman W5PFG 17 Jul '12

17 Jul '12

I'm looking for an inexpensive FT-817 (don't care it's a "D" or "ND" model.) It doesn't need to be cosmetically pretty. I don't necessarily need any of the accessories. Not interested in "packages" with all the accessories and after market accessories unless it's really, really cheap. Need it for a satellite-related project. Email off-list please. Thanks & 73 Clayton W5PFG

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SkyCube launches Funding Campaign on Kickstarter
by Trevor . 17 Jul '12

17 Jul '12

The ArduSat CubeSat project recently succeeded in raising donations of $106,330 in just 30 days on Kickstarter. Now another amateur radio CubeSat project SkyCube is using Kickstarter to raise $82,500 See http://www.uk.amsat.org/?p=8955 73 Trevor M5AKA AMSAT-UK International Space Colloquium Guildford takes place Sept. 15-16 http://www.uk.amsat.org/colloquium/twelve AMSAT-UK News on Twitter: http://twitter.com/AMSAT_UK ----

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antennas for portable use
by Thomas Doyle 17 Jul '12

17 Jul '12

I did a lot of comparisons between my Elk and Arrow II. My results were exactly the same as those of WD9EWK/VA7EWK but I was never sure why the Elk performed better. Comparison tests I have been running between a DIAMOND A430S10R and an Olde Antennas 7CP-70cm have given me an insight as to why the Elk works so much better. The tests between the Diamond and the Olde were the most inconclusive tests I have ever run until suddenly my ancient grey cells managed to figure it out. The Diamond has a longer boom which gives it more gain. The Olde has a very short boom but is circularly polarized. I had them mounted on opposite ends of the cross boom with a switch for quick comparisons. During part of a pass the Diamond would work better. During other parts of the pass the Olde would work better. The chart at the top of the SV1BSX web page holds the answer. http://sv1bsx.50webs.com/antenna-pol/polarization.html When the orientation of the sat antenna lines up with the Diamond it works better and continues to work better until the sat rotates to the point where the cross polarization loss cancels the gain advantage the Diamond has over the Olde at which point the Olde works better... What has this to do with the Elk - Arrow comparison. Since the 2M and 70cm antennas on the Arrow are mounted at right angles to one another we have a problem when working linear polarized sats. If the Arrow is turned to maximize the downlink signal it is automatically turning the uplink antenna to the angle that will maximize the uplink cross polarization loss of up to 30 dB. I do my testing on the linear sats and listen to my own downlink signal. When the Arrow is rotated to maximize the the received signal my best guess is that it is turned off the angle of the sat antenna. This would spread the cross polarization loss between the uplink and downlink antennas. The exact offset angle would depend on transmit power, receive sensitivity and a ton of other things. There is nothing wrong with the Arrow II it just can not work as well as the Elk on linear sats unless you have a quick wrist and rotate the antenna between transmit and receive. Even if you have very quick wrists resulting from a miss spent youth playing foosball there still is a problem. Trying to figure out the angle to turn the antenna during transmit is all but impossible. Since the sat is rotating the angle for transmit is not always 90 degrees from the angle for receive. All antennas work to some degree and all this stuff is only important if you are trying to maximize performance. 73 W9KE Tom Doyle On Mon, Jul 16, 2012 at 3:28 PM, Patrick STODDARD (WD9EWK/VA7EWK) <amsat-bb(a)wd9ewk.net> wrote: > Norm, > > I use an Elk log periodic for AO-7 and all my other satellite work. I am > able to work passes to the predicted LOS time, subject to local > surroundings. > I was only able to work down to 4 or 5 degrees elevation with my Arrow > dual-band Yagi, before I switched to the Elk. You can see this setup > in action working satellites - including AO-7 mode B - in some of > my videos at: http://youtube.com/va7ewk > > For AO-7 in mode A, the Elk is my 2m antenna, and a Buddipole dipole > on its tripod and telescoping mast is used for the 10m downlink. > Since this requires more setup, and the 10m downlink is weaker > than the 2m downlink, I don't work mode A very much. > > 73! > > > > > Patrick WD9EWK/VA7EWK > http://www.wd9ewk.net/ > > > On Monday, July 16, 2012, Lizeth Norman wrote: > >> Hi all! >> Just wanted some comments as to what ops are using for AO-7 portable. >> More importantly, some info on how they perform near loss of signal. >> Pictures of antenna arrays would be greatly appreciated. >> Norm n3ykf >> _______________________________________________ >> Sent via AMSAT-BB(a)amsat.org <javascript:;>. 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 >> > _______________________________________________ > 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 -- Sent from my computer. tom ...

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Circularity question.
by Tom Gentry 17 Jul '12

17 Jul '12

Do I go RHCP on the downlink and LHCP for the uplink or vice versa for Mode B? I may add RH/LH switching later but for now my new antennas will be fixed. Is there a reference that speaks to this issue? 73, Tom K5VOU

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Possible Delay For Mars Science Laboratory Landing Telemetry
by B J 17 Jul '12

17 Jul '12

http://spaceflightnow.com/atlas/av028/120716relay/ 73s Bernhard VA6BMJ @ DO33FL

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ao-7 antennas for portable use
by Lizeth Norman 16 Jul '12

16 Jul '12

Hi all! Just wanted some comments as to what ops are using for AO-7 portable. More importantly, some info on how they perform near loss of signal. Pictures of antenna arrays would be greatly appreciated. Norm n3ykf

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