[amsat-bb] Re: Antenna Question
Hi Doug, I doubt that I have greater understanding of antennas than you do, but I'll give your question a shot. Actually, I have been working on circularly polarizing the ARROWS with the WRAPS lately, a work still in progress but almost complete. So I am throwing out the draft information I have been working on to date. You can circularly polarize a pair of ARROWs and they actually work well together from my experience (one of the reasons I suspect is that the feed system of the individual antennas is very well matched). If you are mounting the two antennas virtually on the same boom (sticking them right next to each other) it might get pretty crowded and interactions complicated. I have mounted two ARROWs separated horizontally about 3 feet apart with pretty good success. I have done this with stock ARROWs, and also with one side with the two meter elements, and the other side with the 70 CM elements (had to drill extra holes for the 70 CM mod), both ways worked about the same. The tricky part is coming up with the right feed lines (the transformer lines and the phasing line). I have a first draft of an article I am working on that describes my latest effort to come up with a polarity switching arrangement for ARROWs with the WRAPS, it can be downloaded here (if you have download issues, let me know and I'll try and get it to you another way). Click here to view Circling the WRAPS https://www.dropbox.com/l/xvKKUtfwUN5gFhGyCiXjua? I will be adding to the conclusion of the piece some suggestions on where to include an external diplexer in the line to handle the single feed line issue that you mention in your post. Anyway, I hope this will stimulate some ideas. Mark Mark Spencer, WA8SME 860-381-5335 mspen...@arrl.org ___ 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
[amsat-bb] Re: Antenna question continued
Jacob, for what it is worth, I built the 'eggbeater' and it was so 'noisy' tossed it. Built the dual Moxon out of brass tubing from the hobby shop and just love it !!! (I'm a big Moxon fan as you can tell) The Moxi works for me. But, since you already have the KLM's, not sure you will do better for LEO omni than that. 73, Ted -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Jacob Tennant Sent: Saturday, May 01, 2010 6:27 PM To: amsat-bb@amsat.org Subject: [amsat-bb] Antenna question continued OK so to continue my antenna question further, I have seen plans for the K5OE Eggbeater antenns, dual moxons for LEO's, as well as the EZ-Lindenblad antennas for small satellite antennas. Of these what is the general consensus as to the better of them? I am looking for something small and easy to setup for Field Day, portable operation where a dual beams and rotator setup would be cumbersome to use. I already have plans for the beams I have to be setup here at the house. Thank you everyone for indulging my curiousity... Jacob Tennant - K8JWT ___ Sent via amsat...@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 via amsat...@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
[amsat-bb] Re: Antenna question continued
In a message dated 5/2/2010 6:46:20 P.M. Eastern Daylight Time, k7trkra...@charter.net writes: I already have plans for the beams I have to be setup here at the house I wish you the best of luck Jacob with your setup. I did quite a bit of outdoor operation with a handheld sat antenna which was fun (3 VHF elements 7 UHF elements). Nice to be able to adjust elevation, azimuth, and polarization with just a twist of the wrist for best reception. Looking forward to hearing you on the birds. - - - I'm located near Charleston. Glad to see another West Virginian here on the list. 73, Gary -K8KFJ- Sat VUCC #125 ___ Sent via amsat...@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
[amsat-bb] Re: antenna question
Some maritime TVRO antennas used a mechanical scan at the feed point. A motor would either rotate an attenuator disk or offset the feed in a circular motion. A resolver kept track of the feed location in relation to received signal strength. The antenna was then slewed in the direction of best signal in both AZ and EL. Sort of a poor mans monopulse system. This works OK for antennas in the microwave region but would not work to well for VHF/UHF low gain arrays. What might work well is to use a pair of antennas with a doppler scan circuit that steered the rotor toward the estimated direction of the signal. Howie AB2S _ Windows 7: Simplify your PC. Learn more. http://www.microsoft.com/Windows/windows-7/default.aspx?ocid=PID24727::T:WLMTAGL:ON:WL:en-US:WWL_WIN_evergreen1:102009 ___ Sent via amsat...@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
[amsat-bb] Re: antenna question
While searching for public text concerning Amateur satellites and phased array antennas, I came across this gem from our very own Tom Clark, K3IO http://mysite.verizon.net/w3iwi/electronic_scanning_antennas.pdf, Electronic Scanning Antennas for Amateur Spacecraft. I wonder if this knowhow could be utilized for ground stations to have antennas that could rapidly switch between different birds by a software reload function and a intelligent switching matrix ? How many of you would prefer (if a command station) to have multi-access to satellites as they pass during conjunction but use a small antenna farm selectively to access them _simultaneously_. On Thu, Oct 22, 2009 at 3:06 PM, Samudra Haque samudra.ha...@gmail.com wrote: Hi, Amsat-BB Are there any antenna designs that use predominantly rotating sub-reflectors and a reflector for tracking LEO birds, in contrast to rotating the main antenna structure on booms in the AZ-EL directions ? I am aware of multi-LNB antenna arrangements, thought it would be interesting to find out ways to keep a fairly large reflector constant on the ground and use a smaller steerable sub-reflector or horn feed to aim the beam ? Any ideas ? Samudra N3RDX ___ Sent via amsat...@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
[amsat-bb] Re: antenna question
This is a great paper and solid work. It doesnt have a chance of being implemented on an amateur radio budget or time scale to the point where a solid reliable platform can be flown. What the satellite group needs is more Oscar 7's (or VO 52's) and Oscar 10...Arsene and Oscar IV were not bad concepts. Face it, we are not going to make working the world on an HT a viable proposition. Robert WB5MZO From: samudra.ha...@gmail.com Date: Thu, 22 Oct 2009 15:16:25 -0400 To: amsat-bb@amsat.org Subject: [amsat-bb] Re: antenna question While searching for public text concerning Amateur satellites and phased array antennas, I came across this gem from our very own Tom Clark, K3IO http://mysite.verizon.net/w3iwi/electronic_scanning_antennas.pdf, Electronic Scanning Antennas for Amateur Spacecraft. I wonder if this knowhow could be utilized for ground stations to have antennas that could rapidly switch between different birds by a software reload function and a intelligent switching matrix ? _ Windows 7: It helps you do more. Explore Windows 7. http://www.microsoft.com/Windows/windows-7/default.aspx?ocid=PID24727::T:WLMTAGL:ON:WL:en-US:WWL_WIN_evergreen3:102009 ___ Sent via amsat...@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
[amsat-bb] Re: antenna question
Samudra, You could use a polar mount and preset mast angle and azmuth before each pass. That will give you a single axis control. Most antennas are moer that 30 degrees in beamwidth, the system only needs to be close +/- 15 degrees to have max signal. Art, KC6UQH -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Samudra Haque Sent: Thursday, October 22, 2009 12:16 PM To: Amsat-bb Subject: [amsat-bb] Re: antenna question While searching for public text concerning Amateur satellites and phased array antennas, I came across this gem from our very own Tom Clark, K3IO http://mysite.verizon.net/w3iwi/electronic_scanning_antennas.pdf, Electronic Scanning Antennas for Amateur Spacecraft. I wonder if this knowhow could be utilized for ground stations to have antennas that could rapidly switch between different birds by a software reload function and a intelligent switching matrix ? How many of you would prefer (if a command station) to have multi-access to satellites as they pass during conjunction but use a small antenna farm selectively to access them _simultaneously_. On Thu, Oct 22, 2009 at 3:06 PM, Samudra Haque samudra.ha...@gmail.com wrote: Hi, Amsat-BB Are there any antenna designs that use predominantly rotating sub-reflectors and a reflector for tracking LEO birds, in contrast to rotating the main antenna structure on booms in the AZ-EL directions ? I am aware of multi-LNB antenna arrangements, thought it would be interesting to find out ways to keep a fairly large reflector constant on the ground and use a smaller steerable sub-reflector or horn feed to aim the beam ? Any ideas ? Samudra N3RDX ___ Sent via amsat...@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 __ Information from ESET NOD32 Antivirus, version of virus signature database 4535 (20091023) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 4535 (20091023) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ Sent via amsat...@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
[amsat-bb] Re: Antenna Question
True, but since the QST article mentioned a phasing line, I was trying to figure out his design. George, KA3HSW - Original Message - From: Nigel Gunn G8IFF/W8IFF ni...@ngunn.net Subject: [amsat-bb] Re: Antenna Question To: George Henry ka3...@att.net Cc: amsat bb amsat-bb@amsat.org, Jim Jerzycke kq...@pacbell.net I would suggest that you don't need a phasing line if the dipoles are spaces a quarter wave and that both are fed by equal length cables. George Henry wrote: Looking at the pictures, it appears that the dipoles are separated by about 1/4 wave in free space, which is physically longer than a 1/4 wave phasing line would be. And I'd think that the phasing line would have to be 1/2 wavelength, after introducing a 1/4 wave offset between the dipoles, correct? ___ Sent via amsat...@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
[amsat-bb] Re: Antenna Question
Sounds like the QHTennas, made by N4QH. Reviewed in QST in 2005, then he stopped producing them just a few months later. Near as I could figure out, they are a conventional turnstile design, but with the 2 dipoles separated by the length of the phasing line, and no reflector. George, KA3HSW - Original Message - From: Joel Black jbbl...@charter.net To: amsat-bb@amsat.org Sent: Saturday, July 04, 2009 9:50 AM Subject: [amsat-bb] Antenna Question Happy Independence Day. Does anyone recognize the following antennas? I purchased them years ago and they were part of a system I never installed. Over the years, one of the elements has been damaged and, even though I can fix it myself, I'd like to know who made these. Doggonit, I cannot upload to my webpage (something else yet to figure out). Suffice it to say, my description may not do the antennas justice. There are two of them, a 2m and 70cm made out of sched 40 PVC. They appear to be a turnstile type antenna with two aluminum elements at the top and two at the bottom 90° out of phase from each other (top and bottom). In other words, if looking at a compass, the top two elements would be at N and S, the bottom two at E and W. This is the same on both antennas as they are a matching set. These antennas were in an old QST, but I have since gotten rid of all those magazines and cannot find the article online. Any ideas or suggestions? Tnx, Joel, W4JBB ___ Sent via amsat...@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
[amsat-bb] Re: Antenna Question
Oh My! Somebody else has my warped sence of humor:-) Just ask my granddaughter. I goof with her all the time with stuff like this. Like when she asks to get on the computer and I tell her she will break it if she does:-) RoD KD0XX --- On Sat, 7/4/09, David - KG4ZLB kg4...@googlemail.com wrote: From: David - KG4ZLB kg4...@googlemail.com Subject: [amsat-bb] Re: Antenna Question To: amsat-bb@amsat.org Date: Saturday, July 4, 2009, 11:28 AM How can you upload a web page if you have your dog on it ? Move the dog first then try! ;-) Happy 4th all! 73 -- David KG4ZLB www.kg4zlb.com Joel Black wrote: Happy Independence Day. Doggonit, I cannot upload to my webpage (something else yet to figure out). ___ Sent via amsat...@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 via amsat...@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
[amsat-bb] Re: Antenna Question
The product review is in the August 2004 QST. If you have access to the reviews page you can find it under the Q listings by manufacturer. Jim KQ6EA --- On Sat, 7/4/09, George Henry ka3...@att.net wrote: From: George Henry ka3...@att.net Subject: [amsat-bb] Re: Antenna Question To: amsat bb amsat-bb@amsat.org Date: Saturday, July 4, 2009, 8:51 AM Sounds like the QHTennas, made by N4QH. Reviewed in QST in 2005, then he stopped producing them just a few months later. Near as I could figure out, they are a conventional turnstile design, but with the 2 dipoles separated by the length of the phasing line, and no reflector. George, KA3HSW - Original Message - From: Joel Black jbbl...@charter.net To: amsat-bb@amsat.org Sent: Saturday, July 04, 2009 9:50 AM Subject: [amsat-bb] Antenna Question Happy Independence Day. Does anyone recognize the following antennas? I purchased them years ago and they were part of a system I never installed. Over the years, one of the elements has been damaged and, even though I can fix it myself, I'd like to know who made these. Doggonit, I cannot upload to my webpage (something else yet to figure out). Suffice it to say, my description may not do the antennas justice. There are two of them, a 2m and 70cm made out of sched 40 PVC. They appear to be a turnstile type antenna with two aluminum elements at the top and two at the bottom 90° out of phase from each other (top and bottom). In other words, if looking at a compass, the top two elements would be at N and S, the bottom two at E and W. This is the same on both antennas as they are a matching set. These antennas were in an old QST, but I have since gotten rid of all those magazines and cannot find the article online. Any ideas or suggestions? Tnx, Joel, W4JBB ___ Sent via amsat...@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 via amsat...@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
[amsat-bb] Re: Antenna Question
Yeah, I found the review on the ARRL web site by searching for QHTenna. Looking at the pictures, it appears that the dipoles are separated by about 1/4 wave in free space, which is physically longer than a 1/4 wave phasing line would be. And I'd think that the phasing line would have to be 1/2 wavelength, after introducing a 1/4 wave offset between the dipoles, correct? In answer to Joel's original question, there is a link at www.qhtenna.com for questions or support for owners of existing QHTennas. They should be pretty easy to duplicate, at any rate. George, KA3HSW - Original Message - From: Jim Jerzycke kq...@pacbell.net To: amsat bb amsat-bb@amsat.org; George Henry ka3...@att.net Sent: Saturday, July 04, 2009 1:54 PM Subject: Re: [amsat-bb] Re: Antenna Question The product review is in the August 2004 QST. If you have access to the reviews page you can find it under the Q listings by manufacturer. Jim KQ6EA --- On Sat, 7/4/09, George Henry ka3...@att.net wrote: From: George Henry ka3...@att.net Subject: [amsat-bb] Re: Antenna Question To: amsat bb amsat-bb@amsat.org Date: Saturday, July 4, 2009, 8:51 AM Sounds like the QHTennas, made by N4QH. Reviewed in QST in 2005, then he stopped producing them just a few months later. Near as I could figure out, they are a conventional turnstile design, but with the 2 dipoles separated by the length of the phasing line, and no reflector. George, KA3HSW ___ Sent via amsat...@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
[amsat-bb] Re: Antenna Question
I would suggest that you don't need a phasing line if the dipoles are spaces a quarter wave and that both are fed by equal length cables. George Henry wrote: Looking at the pictures, it appears that the dipoles are separated by about 1/4 wave in free space, which is physically longer than a 1/4 wave phasing line would be. And I'd think that the phasing line would have to be 1/2 wavelength, after introducing a 1/4 wave offset between the dipoles, correct? ___ Sent via amsat...@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
[amsat-bb] Re: Antenna Question
That's them. Thanks, George and, David, I got the dog off the webpage. ;) Tnx, Joel, W4JBB George Henry wrote: Sounds like the QHTennas, made by N4QH. Reviewed in QST in 2005, then he stopped producing them just a few months later. Near as I could figure out, they are a conventional turnstile design, but with the 2 dipoles separated by the length of the phasing line, and no reflector. George, KA3HSW - Original Message - From: Joel Black jbbl...@charter.net To: amsat-bb@amsat.org Sent: Saturday, July 04, 2009 9:50 AM Subject: [amsat-bb] Antenna Question Happy Independence Day. Does anyone recognize the following antennas? I purchased them years ago and they were part of a system I never installed. Over the years, one of the elements has been damaged and, even though I can fix it myself, I'd like to know who made these. Doggonit, I cannot upload to my webpage (something else yet to figure out). Suffice it to say, my description may not do the antennas justice. There are two of them, a 2m and 70cm made out of sched 40 PVC. They appear to be a turnstile type antenna with two aluminum elements at the top and two at the bottom 90° out of phase from each other (top and bottom). In other words, if looking at a compass, the top two elements would be at N and S, the bottom two at E and W. This is the same on both antennas as they are a matching set. These antennas were in an old QST, but I have since gotten rid of all those magazines and cannot find the article online. Any ideas or suggestions? Tnx, Joel, W4JBB ___ Sent via amsat...@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 via amsat...@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
[amsat-bb] Re: Antenna Question
It surprises me that nobody appears to sell commercially made Lindenblads. Jim Jerzycke wrote: An altenative would be to build a Lindenblad like Tony AA2TX designed. I have the parts collected to do just that, but won't have the time to build one for a few weeks. ___ Sent via amsat...@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
