and here is a servo command board http://endurance-rc.com/
they say with a high gain antenna you could get 50km los what you think? I dont know any visual basics and I have not made a fpv system before do you think this is feasible for a noob? thanks
I have stp enabled on two radios.
usually stock ubnt will get you 3km range
I use only ubiquiti radios currently no other rx on the aircraft.
Forget the 50km link distance - that will be a theoretical link distance against a background of ideal circumstances, circumstances that are seldom defined by the manufacturer and which did certainly not include one side of the link moving/flying around. You'll be lucky if you get 5km. Don't consider that bad - it's typical in reality of most hardware that claims XXkm link distances.
Dal - spend some time looking at Ubiquiti Networks (http://www.ubnt.com/) rf link options - they produce some interesting wifi hardware. I have no experience using any of it on RC/FPV/UAV type models, but I have experience using their 700Mhz and 900Mhz wifi hardware - and set up properly its good gear quite capable of 5km -10km plus link distances in the right cirucmstances.
If you really want real world usable & reliable link distances of the sort you have in mind, then whatever hardware you use, you are going to have to use amplification - serious amplification, which is generally far more power than the average sized model will be able to practicaly carry: the battery mass will be so much that the model will have used it all up before anywhere near the theoretical distance is flown.
Your other option: take a look at http://webx.dk/rc/rc.htm. Thomas has a well established reputation for producing long distance rf link hardware that works well and is within the budgets that amatuer/hobby flyers are willing to pay.
5.8 Ghz WiFi (only wifi, not analog video) can send up to 1000 mW / 26 dBm and you can get a Ubiquiti Networks 5G WISPStation for about 45$. As I can understand You can configure these as bridge or station. On the other side 5.8 Ghz is really LOS sensitive: anything between the antennas will eat dBm's.
I will start some experiments with that hardware and a small IP video server (with 4 chanells) soon, because I need a 'legal' video link, and here in switzerland you can't use quiet nothing with a range higher than 500m in analog mode.
Another thing to consider is reliability - losing a link at 50 km from base is not a good thing. It won't be legal to fly away from visual range either :-)
You will get units of km from this rig at best - the datasheet specifies the best sensitivity being -90 dBm at 1 Mbps and maximum TX power of 20 dBm - assuming you use the 3 dBi dipole antenna on the aircraft and a directional but still aimable patch or yagi with say 10 dBi of gain you end up with a usable range of a little over 5 km (with 5 dB of fade margin left - barely enough for a stable link). That would be the outskirts of your UAV range and you will fear to thread too close to it :-)