Radio System for 1 mile

[blackhawk444]

Hello. I am interested in UAV's, however do not have anywhere near the funds to make a real one. I am working on a conventional rc plane with a 2.4ghz video down link (rated for 1 mile). The plane that I am using comes with a plain radio. I was wondering what I could use to reach about a mile away? Also would location matter (could I use it inside by my tv?). Sorry if there was another thread on this, I tried searching and did not find anything. Thanks alot!

[Capt. Crunch]

I'm at about the same stage as you are on a Mini UAV.

Are you asking about the 2.4 Ghz tv or the RC 72 Mhz system?

Generally the 72 Mhz RC System, if using good quality equipment, will carry as far as you can safely see the a/c.

Alan Cocconi uses a stock JR transmitter with a high gain antenna, omni directional, for 4 mile glitch free use.
I'm not sure on his on-board 2.4 Ghz TV & telemetry, but I'm pretty sure he's just using a high gain helix antenna with auto pointing to the A/C. See http://www.acpropulsion.com/solong/
for more detail.

Hope this helps,

Wayne

BTW, I'm usign a GWS Beaver as test bed, FMA Co-Pilot, generic 2.4Ghz tv to date. Will try to integrate RCAP, GPS and Auto Thermal next. Goal is to fly a 4 M Motor Glider I have at home in the Sierras in 2008.

[kd7ost]

A good quality standard RC system will work up to 1 mile. But not well along the ground or with a lot of obstacle ground clutter. Get rid of the park flyer stuff that comes with the 99.00 RTF plane.

You need to ask one heck of a lot of "what if's" first though or it becomes an excersise in stupidity. Then you need to be able to have an answer for each "what if".

Questions like.

1. How do I know I hit the edge of my RC range?

2. Where does the plane go once I've hit the edge and lose it?

3. What is the population density of the public down range or within current fuel capacity?

If you don't have a handle on risk mitigation in these instances, and they will happen, you have no business doing it. No one does.

Dan

[blackhawk444]

Thanks for the responses. Could you recommend some quality radio systems? There are some trees, but not much else. No tall buildings. Could you answer those questions?..lol. I was thinking about walking the plane out to a point and testing if it is fully working with the radio. I would assume the the controls would start to cut out if it hit the edge. Population is pretty low. Just large houses with lots of yard space. No towns or cities. I am not going to do anything crazy. The max I will go is probably .5 of a mile due to added risks of going out farther. Thanks.

[kd7ost]

Thanks for the responses. Could you recommend some quality radio systems? There are some trees, but not much else. No tall buildings. Could you answer those questions?..lol.


What country do you live in? Different places in the world have different equipment. I only know of brands sold in America. You don't list where you're from.

Dan

[blackhawk444]

I am in the US...Thanks.

[kd7ost]

Just buy a 4 channel or better FM Hitec, Airtronics, JR or Futaba and you'll be OK.

Dan

[blackhawk444]

OK I think I am going to buy the Futaba 100$ 4 channel model. Is there a way to make it get more range? (make a better antenna somehow?). Also does flying by camera take alot of skill? Thanks...

[kd7ost]

The output power circuitry is tuned specifically for the length of the antenna. I don't think you'll have much luck finding a high gain Yagi style antenna at 72 Mhz. I would leave it stock.

Holding your transmitter antenna straight up will help in range because it radiates energy from the long edge out in a doughnut shape.

The receive antenna is the same way. If you fly with the receive antenna pointed right at you or away from you, this is the worst possible distance scenario. It should be standing up if possible. There are aftermarket antenna's that can be used that are short and stand straight up. I've never used one of those though.

Hard is a relative term. FOV and familiarity with one's surroundings make a huge difference. Also having a plane that is inherently stable. Something that will fly itself as much as possible. You don't want a handful on your hands. Concider a co-pilot CPD4 for pitch and roll stability as a good starting point. It will allow you to fly more or less hands off.

You should use a spotter and take it in small steps. A little at a time. You have to teach yourself to do it so don't bite off big chunks till you are ready.

Dan

[blackhawk444]

I am going to be using a flying wing type airplane. I am def. going to practice before really flying it. So a standard radio with the antenna up should be able to reach about .5 of a mile? If so that is great news. Thanks a lot Dan.

[E.N.]

You should always be able to look up and regain control of the plane. This means no flying inside while your plane's outside. A standard radio(i.e. JR, futaba, Hitec, and airtronics) will give you .5 mile LOS easily. It has more to do with the rx, I recommend the berg 7p because of zero glitching and failsafe mode.
The UAV forum is more for autonomous flight, try the FPV forum.

Ian:cool:

[blackhawk444]

The whole point is this project is to not be able to see the plane while its flying. Would the radio be able to go through trees? I will look into the berg receiver...Thanks.

[E.N.]

The signal will be degraded as it goes through obstacles. What I meant was that you are wanting to fly your plane in first person view by video. The FPV forum http://www.rcgroups.com/video-piloting-fpv-rpv-469/ is just for that.

Ian:cool:

[blackhawk444]

Well I have been doing more research. I have decided that I am going to try to step into the UAV section. Whole systems cost way to much money. I was thinking about working on one that would turn on with a aux. switch on my radio and then fly to a GPS location preprogrammed into it. Once it returned I could disable it and land it manually. Would this be obtainable with a budget under 1K? Also could I impliment this system with a flying wing type airplane? Thanks alot, Andrew.

[Capt. Crunch]

<$1k, don't see why not. the flight profile you describe should work fine with simple equipment. Landing and take off automously are the difficult parts, as are long range radio control.

[phubner]

Blackhawk,

I've built a first person flight aircraft based on an Easystar and 2.4 Ghx downlink. Including an upgraded brushless electric motor, 6ch futaba EXAS (thanks ebay), video goggles, it has cost me less that $700 so far. I'm of course not including my time in that cost!

I am now in the process of adding a GPS based Return-to-Home capability as I lost my downlink once -- quite scary when you are out of visual range although I was in the right area for testing with lots of open land. My custom controller is based on the ironically named Propeller chip by Parallax.com. I bought the dev kit for ~$50 total. Its a good deal and there is a vibrant community of developers who, like me, post their code openly in the forums.

I have already developed a program that takes control of the servos when my (unused) gear switch is toggled. I'm writing the GPS parsing and navigation routines now. I've posted the servo control routine already and will do the same for the nav once I get it done.

Check it out if you are interested at the forums.parallax.com site.

Paul

btw - im not affiliated with Parallax, I just like their stuff :-)