New players, these get good reviews of performance. Claims of 8-12 Km on 2.4Ghz at only 500Mw. http://www.fpvlr.com/store I wonder if you could use these for the RC control?
This is a cloverleaf with a helical combo. Even better yet for long range. You get the high gain with the helical, and circular polarization to reject multipath.
The problem is that where you get gain, you get directivity and where you get directivity, you have the problem of staying on target. If you had an intelligent and automated tracking system, this would work great. For video you could have an assistant that tracked for you based on received signal strength and visual observation. For control this doesn't work because the receiver is on the wrong end of the circuit. You could build a tracking system based on GPS position relative to your control point. If you did that, you could use a really high gain antenna. ...Tiger
I don't see any "combo". You just pick a pinwheel (cloverleaf) for the transmitter and a helix for the receiver on the right frequency. ...Tiger
The cloverleaf is excellent, but the gain doesn't compare to the helix. On the bright side, it's omnidirectional. Just a matter of how much range you need and how you're going to deal with the directivity issues. ...Tiger
With two cloverleaf you do get a touch of gain, but omni directional on both ends, and multipath help from CP. So for normal FPV use it is the way to go to get started. A helical antenna on the ground with a cloverleaf in the sky is for really loooooong range flying. Like 20 miles away type stuff. Most people do use an antenna tracker, but for rotorcraft you could fly within your pre-set beam and with NAZA loiter GPS hold you could just re-adjust your own antenna after just setting the "parking brake" in the sky ;D Most super long range video has been straight polarized stuff like a whip antenna on the aircraft and a patch/yagi antenna on the ground with maybe a diversity whip antenna next to the patch. This works well, but circular polarized, high gain gives the best of both worlds. You could still do a diversity setup on the ground with a helical and cloverleaf which would offer the long and short of flying ranges. Look at this guys setup at 2:00 into the video. Same exact antenna we are talking about for the ground station: http://vimeo.com/43331117
PP - There was a good shot of the antenna tracker in that video. Pretty cool! I don't think I'd ever use a clover on both ends. It's super on the transmit end because it's so omnidirectional, but on the receive end directivity is not such an issue. I think the patch is still a much better choice. A circular patch would be the best, but it's hard to find and difficult to make. Even with the polarization loss of a linear patch, you have so much more gain. If you had 9db of gain and lost two or three to polarization, you'd still be about six ahead. Here is another awesome video from that guy. I guess you just have to kiss your stuff goodby before every flight and hope for the best. http://vimeo.com/37031136 ...Tiger
