Ron,
Been there, Done that. I am using a Directive Systems Looper antenna for 1.2 GHz. With the setup I have, I chose a 6 foot long version with a 30 degree beamwidth rather than the 12 foot long antenna. It works quite well when AO-51 is put in L/U mode as was done several months back for channel B. You can check out my satellite antenna setup on QRZ.
I am using the IC-910 with the 1.2 GHz module. Works great. Figure about half of your output will ever reach the antenna. I selected Belden 9913F7 ultraflex cable which is ideal for my installation. Keep the runs as short as possible. Probably better, if it works for you, would be LMR-400 or 600 or hardline.
For a given length CP Yagi, the gain of the antenna is going to increase as the frequency increases (more elements, etc) and beamwidth of the antenna is going to become more narrow. So pointing the antenna accurately becomes a more significant factor. It's time to go out and buy the elevation rotor. You'll find that it is worth every penny you put into it. A beamwidth of 30 degrees on 1.2 GHz gives the half power points as 15 degrees either side of the antenna position. You don't really want to be 15 degrees off. You want to keep the satellite well within the main lobe of the antenna. At 1.2 GHz, starting with 10 watts, figure half of that gets to the antenna. You don't want to throw away half or all of what's left because the antenna isn't pointed at the satellite. Elevation control will also reduce your power requirements on all of your uplinks.
Date: Sun, 11 May 2008 20:49:23 -0500 From: Ronald Nutter rnutter@networkref.com Subject: [amsat-bb] Suggestions for Mode L antenna To: amsat-bb@amsat.org Message-ID: 4827A223.6020304@networkref.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I am considering purchasing the 1.2 ghz module for my IC-910H. For my satellite work, I have my antennas angled at about 20 degrees since I dont have an az/el rotor. This setup worked reasonably well with Mode S this weekend. What are my chances to be able to work Mode L with this kind of setup ? Also, I would appreciate any suggestions for an antenna that I could use. With only 10 watts, I am not expecting a great signal but I would hope to have at least a readable signal. Also, would appreciate any suggestions as to coax/feedline that I should look at buying ?
Thanks,
Ron KA4KYI
John:
I am using a "budget" rotor from Channel Master for my current setup. Is that strong enough to support an elevation rotor or do I need to save up some $$$ and get an AZ/EL rotor ? It looks like Yaesu is the only option I can find. Are there others that I should look at ?
Ron
John Kopala wrote:
Ron,
Been there, Done that. I am using a Directive Systems Looper antenna for 1.2 GHz. With the setup I have, I chose a 6 foot long version with a 30 degree beamwidth rather than the 12 foot long antenna. It works quite well when AO-51 is put in L/U mode as was done several months back for channel B. You can check out my satellite antenna setup on QRZ.
I am using the IC-910 with the 1.2 GHz module. Works great. Figure about half of your output will ever reach the antenna. I selected Belden 9913F7 ultraflex cable which is ideal for my installation. Keep the runs as short as possible. Probably better, if it works for you, would be LMR-400 or 600 or hardline.
For a given length CP Yagi, the gain of the antenna is going to increase as the frequency increases (more elements, etc) and beamwidth of the antenna is going to become more narrow. So pointing the antenna accurately becomes a more significant factor. It's time to go out and buy the elevation rotor. You'll find that it is worth every penny you put into it. A beamwidth of 30 degrees on 1.2 GHz gives the half power points as 15 degrees either side of the antenna position. You don't really want to be 15 degrees off. You want to keep the satellite well within the main lobe of the antenna. At 1.2 GHz, starting with 10 watts, figure half of that gets to the antenna. You don't want to throw away half or all of what's left because the antenna isn't pointed at the satellite. Elevation control will also reduce your power requirements on all of your uplinks.
Date: Sun, 11 May 2008 20:49:23 -0500 From: Ronald Nutter rnutter@networkref.com Subject: [amsat-bb] Suggestions for Mode L antenna To: amsat-bb@amsat.org Message-ID: 4827A223.6020304@networkref.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I am considering purchasing the 1.2 ghz module for my IC-910H. For my satellite work, I have my antennas angled at about 20 degrees since I dont have an az/el rotor. This setup worked reasonably well with Mode S this weekend. What are my chances to be able to work Mode L with this kind of setup ? Also, I would appreciate any suggestions for an antenna that I could use. With only 10 watts, I am not expecting a great signal but I would hope to have at least a readable signal. Also, would appreciate any suggestions as to coax/feedline that I should look at buying ?
Thanks,
Ron KA4KYI
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
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Date: Mon, 12 May 2008 15:17:03 -0500 From: rnutter@networkref.com To: jkopala@gmail.com CC: amsat-bb@amsat.org Subject: [amsat-bb] Re: AMSAT-BB Digest, Vol 3, Issue 239
John:
I am using a "budget" rotor from Channel Master for my current setup. Is that strong enough to support an elevation rotor or do I need to save up some $$$ and get an AZ/EL rotor ? It looks like Yaesu is the only option I can find. Are there others that I should look at ?
Ron
Hi Ron,
My Az rotor is a ham type (pedigree unknown), but the elevation rotor is a simple Alliance U-110. I think I paid something like $5.00 for a pair of them. As you scan see in the pictures, it handles quite a lot, as long as the balance is kind of close. If it matters, I chose to put a simple screw into the horizontal shaft where the Elevation rotor drives it, so it's not super stiff at that joint. Gives the motor a little "give" when starting.
Greg KO6TH
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participants (3)
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Greg D. -
John Kopala -
Ronald Nutter