back on the birds after 15-year absence - want tips on antenna system
I was an active Satellite operator back in the AO-10, AO-13 and Radio Sputnik days (as AA6TT) and am just getting back on the birds after a near 15-year absence and am getting used to today's LEO sats. I completely missed AO-40. VERY surprised to learn AO-7 is QRV!
I presently have an Arrow antenna on a tripod located indoors. Rig is a FT-847 with MacDoppler tracking software. I successfully heard the 70cm CW beacon from HO-68 earlier today so it's nice to know everything works. Will be attempting QSOs on future passes on this and other LEO birds.
I will be building a more robust outdoor antenna system in a few months and want to make sure I am prepared for the satellites which may be launched in the next few years.
Here is what I am thinking (overkill for LEO birds but I want to be ready to MEO & HEO sats):
10m Dipole V M2 2M-CP14 or Gulf Alpha 2M-8ELSat and SSB Electronic mast-mounted preamp U M2 436CP-30 or Gulf Alpha 70CM-16ELSat and SSB Electronic mast-mounted preamp
Questions:
(1) RHCP for the V and U Yagis? Any reason to have switchable polarity?
(2) Anyone who has used both M2 and Gulf Alpha satellite antennas please comment on their relative merit.? I find M2 on-air performance to be very good however I have had problems with M2 feed-point failures.
(3) Will next gen ham satellites have S-Band downlinks?
(4) Will next gen ham satellites have L-Band uplinks and/or downlinks?
(5) Other bands to be prepared for?
(6) Are these the satellites currently available for 2-way QSOs? AO-7, AO-27, AO-51, SO-67 & HO-68. Did I miss any?
(7) Any pattern to when AO-7 is in Mode A and Mode B?
73, Bill
-----
William Hein, AA4XT
mobile: +1 (615) 967-1226 email: Bill.AA4XT@Gmail.com Loc: EM65PS Web: AA4XT.com
6752 Owen Hill Road College Grove TN 37046-9122 USA
Welcome back Bill. My last sat QSO was via Oscar 8.
William Hein wrote:
I was an active Satellite operator back in the AO-10, AO-13 and Radio Sputnik days (as AA6TT) and am just getting back on the birds after a near 15-year absence
Welcome back! I'll try to answer what I can.
Questions:
(1) RHCP for the V and U Yagis? Any reason to have switchable polarity?
Some LEOs have different circularities for different transmitters. For example, AO-51 has both LHCP and RHCP on 70cm. The sense can also change during a pass depending on spacecraft orientation and squint. Switchable polarity is well worth it in my opinion.
(3) Will next gen ham satellites have S-Band downlinks?
Yes, and AO-51 has an S downlink now, usually about 1 week a month. P3E and others will have S.
(4) Will next gen ham satellites have L-Band uplinks and/or downlinks?
Yes, and AO-51 and CO-65 use L now also. Kiwisat and P3E will have L also.
(6) Are these the satellites currently available for 2-way QSOs? AO-7, AO-27, AO-51, SO-67 & HO-68. Did I miss any?
Off the top of my head, add ISS, SO-50, VO-52, FO-29 (due to return soon), NO-44 sometimes, CO-65 for a real digital challenge. Lots of one-way cubesats that can be fun too.
(7) Any pattern to when AO-7 is in Mode A and Mode B?
Right now the satellite is in 24/7 illumination, and the onboard timer switches modes every 24 hours or thereabouts. Check http://oscar.dcarr.org/ as a quick way to figure out which one is on right now. When it returns to eclipses, it generally favors B and only works while illuminated.
I hope that helps. Joining AMSAT if you're not already a member is a good way to support the program, and there is always something interesting in the AMSAT Journal. There are several active ops in your immediate area, including a BOD member; they may chime in. See ya on the air soon.
73, Drew KO4MA
Nice, informative response Drew...I'm keeping this one on the wall!
Roger WA1KAT
----- Original Message ----- From: "Andrew Glasbrenner" glasbrenner@mindspring.com To: "William Hein" bill.aa4xt@gmail.com Cc: amsat-bb@amsat.org Sent: Monday, December 28, 2009 9:27 PM Subject: [amsat-bb] Re: back on the birds after 15-year absence - want tipson antenna system
Welcome back! I'll try to answer what I can.
Questions:
(1) RHCP for the V and U Yagis? Any reason to have switchable
polarity?
Some LEOs have different circularities for different transmitters. For example, AO-51 has both LHCP and RHCP on 70cm. The sense can also change during a pass depending on spacecraft orientation and squint. Switchable polarity is well worth it in my opinion.
(3) Will next gen ham satellites have S-Band downlinks?
Yes, and AO-51 has an S downlink now, usually about 1 week a month. P3E and others will have S.
(4) Will next gen ham satellites have L-Band uplinks and/or downlinks?
Yes, and AO-51 and CO-65 use L now also. Kiwisat and P3E will have L also.
(6) Are these the satellites currently available for 2-way QSOs? AO-7,
AO-27, AO-51, SO-67 & HO-68. Did I miss any?
Off the top of my head, add ISS, SO-50, VO-52, FO-29 (due to return soon), NO-44 sometimes, CO-65 for a real digital challenge. Lots of one-way cubesats that can be fun too.
(7) Any pattern to when AO-7 is in Mode A and Mode B?
Right now the satellite is in 24/7 illumination, and the onboard timer switches modes every 24 hours or thereabouts. Check http://oscar.dcarr.org/ as a quick way to figure out which one is on right now. When it returns to eclipses, it generally favors B and only works while illuminated.
I hope that helps. Joining AMSAT if you're not already a member is a good way to support the program, and there is always something interesting in the AMSAT Journal. There are several active ops in your immediate area, including a BOD member; they may chime in. See ya on the air soon.
73, Drew KO4MA _______________________________________________ Sent via AMSAT-BB@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
Bill,
Welcome back to the Satellite community, it's an exciting time to be "satellite active"!! You asked a bunch of good questions, most of your answers can be found by visiting www.amsat.org. When your at the site on the left column look for AMSAT Site Menu" scroll down to about eleven items to AMSAT video news and listen to Dayton 2009 ,Barry Baines excellent presentation on the direction of the program. I think his remarks will answer most of your questions. Bill, have a Healthy and Satellite filled NEW Year, hope to work you on the "birds".
73, Pete, WB2OQQ AMSAT Area Coordinator
participants (5)
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Andrew Glasbrenner -
Nigel Gunn G8IFF/W8IFF -
Peter -
Roger Kolakowski -
William Hein