|Oct 24, 2010, 05:19 AM|
David22, I'd like to avoid using a booster if possible. the reason we need a yagi is to blast through houses far away, as we want to fly 40km but at ground level. I can take a dropout of the video for 2-3 seconds, but control must be strong. That dictates we always have 20dbi margin, which we don't this far out. So we must use high-gain yagis (9 - 11dbi) in order to up the power to the required level.
thanks for all the suggestions guys, I'm looking through them right now!
|Oct 24, 2010, 09:44 AM|
What gain are you looking for? Here's a 12dbi unit: http://www.directivesystems.com/PDF/DS432-11R.PDF
|Jan 03, 2011, 10:54 PM|
Okay, I've been thinking all along that Yagi's were used for video reception over long ranges. But if you're using Yagi's on UHF frequencies, then are you using them to SEND your RC signal to your UHF receiver onboard the plane?
Pardon me for my ignorance, but this is the first I'm hearing of that.
So do you guys have 433mhz Yagi's for RC transmission AND 2.4ghz Yagi's for video reception on a single base station?
I don't understand how you'd manually point those antennas, seems like you'd need an antenna tracker to be accurate.
Are there any antenna trackers that would work with the DragonLink? I like the DOSD+, so I'm thinking DL all the way on my setup. But the EzUHF is the only one I've seen that has the antenna tracker features as part of the product suite.
Sorry, questions on several topics, but would love feedback from the "pros" on this thread.
|Jan 04, 2011, 12:27 AM|
North vancouver, B.C. Canada
Joined Apr 2008
you put both yagi's on a pole that can be aimed at the plane.
both yagi's are in the same polarization and alignment.
But spaced apart by a minimum of 70 cm
the video yagi goes on top because it is the weakest and needs more height
you do the manual aiming by useing the video reception
when in close for like inflight flying, or to land, the manual aiming is not really needed, the video is good for flying close range with a video yagi and uhf is for sure not needed to be aimed at close range.
Divercity, antenna trackers and other things are just a possable weak link that could cause you future problems IMHO
I like to keep things as simple as possable
|Jan 04, 2011, 12:57 AM|
Okay, that's totally awesome. Thanks for the info David.
I just placed a HUGE order for 2.4ghz AV gear, following Trappy's recommendation. I must wait a little while to build up the funds to get the UHF stuff. I'll fly 72mhz to begin with in close range while training and getting used to flying through a camera, then get the UHF gear with another Yagi on 433mhz for long range stuff.
I had no idea you guys were pointing your Yagi's manually. I mean, the way the BlackSheep guys fly, I can't imagine they'd have a free hand to do that sort of thing! So if your signal starts to get a bit blurry, you just start moving your antenna around until it cleans up?
Wow. Low tech, but puts control of the entire experience in the pilots hands. I kind of like that.
Gives new meaning to the phrase "Mad Skills"! Ya gotta be mad to do that, and it sure takes skills!
So, question about the video transmitter. Do you just use the little 2.4ghz black antenna that it comes with for video transmission, or do you use something fancy for that as well?
|Mar 23, 2014, 10:54 PM|
Australia, VIC, Berwick
Joined Oct 2013
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