I've been reading up with great enthusiasm about the amateur payloads being carried into space lately and I would definitely like to take advantage of them. The biggest thing that has always kept me from doing anything with the birds full time has been a decent antenna array. At the moment, my sat station consists of a Kenwood TH-D7AG and an arrow handheld antenna. While it works fine, and I have made close to a dozen contacts or so with it, it's a little discouraging to be outside with it in the winter months.
I know this question probably gets asked many times, but what would be the best antenna to work LEO birds like AO-51 and some of the cubesats coming online here soon? Looking at some of the commercial antenna systems available are a little out of my budget, and I absolutely suck at building my own and don't really enjoy that aspect of the hobby anyhow. I'd also like to do something without an AZ/EL rotor, as I can't fit that into particular setup at this point in time.
So I guess in essence what would be the best "bang for the buck" for what I am trying to accomplish here?
73's Stephen N1VLV
... but what would be the best antenna to work LEO birds like AO-51 and some of the cubesats ... without an AZ/EL rotor...
That is the right approach. A simple $75 TV rotator will do 98% of what the $600 AZ/EL mounts can do for LEO's. AND you don't need the LONG yagi's either, since they are only needed for high orbiting satelits of which there are none right now.
Remember these numbers. 66% of all pass times are below 20 degrees elevation. 85% are below about 45 degrees and 98% are below 60 degrees or something like that. So just put your arrow on a TV rotator and tilt it up about 15 degrees. Done.
If you can't see down to 15 degrees above the horizon due to trees, then you are already losing out on 66% of all pass times, but then you may as well tilt up to about 30 deg and nail the remaining 33% with a little more gain. You don't need any gain abouve 30 deg, because the satellite is already 6 to 10 dB closer to you than it was on the horizon anyway. That is why a fixed antenna at 15 degrees works very well. See it all on http://www.ew.usna.edu/~bruninga/rotator1.html.
Bob, WB4APR
Commercial, shareware and freeware...
http://www.dxzone.com/catalog/Software/DSP/
73, Alan VE4YZ AMSAT 35968
participants (3)
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Alan Thoren
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Robert Bruninga
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Stephen Brown Jr