FPV long distance challenge/competition...

bicyclemonkey

Flying Derp
Mentor
A challenge to test the range to see who can go out the farthest and return...utilizing OSD and return to home functions so the plane will turn around when the range limit has been achieved. Also try to have the plane make a full round trip instead of hitting it's range and going down from a dead battery. Basically who can make it the farthest out and back. This would duplicate real-world issues that have to be overcome by normal FPV pilots.

It would probably be best to have it be a challenge/competition playing on behalf of a forum member. I see Josh B. and David W. competing here. Each would have to pick the planes/equipment they think will best win them the challenge.

...or something like that :)
 

Christian

Junior Member
Is it all about the range or should this be a frequency challenge? my example in the other thread (8km with 5,8ghz) is much more respectable than 8km with 900/1200 mhz. I think trappy and those guys from team black sheep are using 2,4ghz but I dont know their setups exactly.

For every beginner I can just recommend the homepage from david , (www.rcexplorer.se) here you can learn about the basics of fpv and also how to build you own fpv antenna. When you want to get max range of your system the antenna is the easiest way. go for it :)
 

ananas1301

Crazy flyer/crasher :D
tionYeah but if everyone´s going to use a different frequency then it is no wonder that with 5Ghz you won´t get the range as with 900Mhz.

In theory we should be able to calculate the distance to a given frequency: If you reached 100m with 1Ghz and 200m with 0.5Ghz (just examples) then you´ll get 150m with 0.75Ghz.


So my suggestion to this would be not only to compare the actualy ranges made but also the the range reached per single herz if you can all follow my thoughts! :) That would be also quit interesting.
 
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colorex

Rotor Riot!
Mentor
Though you'd violate like a million FCC rules :) and you'd have to build your own Tx from scratch.
 

JoeyG

Senior Member
*wishes he had an FPV setup* oh well.... Maybe next year (no maybe about it..) sounds like a plan, sure many would learn from the fews mistakes.

J.
 

bmsweb

Site Moderator
Man I'm too new to all this FPV stuff . . So far I've don't a whopping . . . . 210 meter :D

I'm interested to see how this thread goes and what people come up with.
 

JimCR120

Got Lobstah?
Site Moderator
Yeah but if everyone´s going to use a different frequency then it is no wonder that with 5Ghz you won´t get the range as with 900Mhz.

In theory we should be able to calculate the distance to a given frequency: If you reached 100m with 1Ghz and 200m with 0.5Ghz (just examples) then you´ll get 150m with 0.75Ghz.


So my suggestion to this would be not only to compare the actualy ranges made but also the the tange reached per single herz if you can all follow my thoughts! :) That would be also quit interesting.

When txrx systems are made the frequency does impact the wave propagation and thus range but there are many other factors involved.

When I was in the USN I worked on radios. I know a little theory but more what we actually used. Your UHF and VHF radios get LOS (line of sight) ranges which only goes out to the horizon of the earth which is about 20 miles out at sea level. When altitude is increased the max theoretical range goes up too. This is why there are satcom radios. These radios send their signal to a satellite which relays it back out increasing the range dramatically. Atmospherics also affect transmission wave range. Our lower freq radios (below 30 MHz) would go half way around the earth but then they are cranking out much more power to do that.

Another very important factor for the max range of a system is the receiver and its initial signal reception. With everything electronic there is noise; I don't mean what we hear but rather radio frequency noise. There is ambient noise and receiver noise. There is not much you can do about ambient noise since what is out there is there and somethings are just always on. Receiver noise however can be controlled and the less there is the weaker an incoming signal can be and still be detected by the receiver. So when people look at receivers they make sure the receiver sensitivity is a low number (measured in -dB).

At our level, unless we have testing equipment (like Bruce who at least has a spectrum analyzer showing a cross section of RF), our most effective means is to ask around and compare. In a nutshell the most important numbers we are looking at will be the radio frequency (deconflicted), transmitter power (hi), and receiver sensitivity(low).
 

bmsweb

Site Moderator
With everything electronic there is noise; I don't mean what we hear but rather radio frequency noise. There is ambient noise and receiver noise. There is not much you can do about ambient noise since what is out there is there and somethings are just always on. Receiver noise however can be controlled . .

I really never took noise into consideration Jim, you're 100% correct. I think I need to do a little more research in to what items in the aircraft cause noise etc (ie ESC placement in the aircraft etc). I will look into this and would be interested in what other come up with. I think it will do your . . sorry I mean my FPV Gear the world of good :p
 

ananas1301

Crazy flyer/crasher :D
When txrx systems are made the frequency does impact the wave propagation and thus range but there are many other factors involved.

When I was in the USN I worked on radios. I know a little theory but more what we actually used. Your UHF and VHF radios get LOS (line of sight) ranges which only goes out to the horizon of the earth which is about 20 miles out at sea level. When altitude is increased the max theoretical range goes up too. This is why there are satcom radios. These radios send their signal to a satellite which relays it back out increasing the range dramatically. Atmospherics also affect transmission wave range. Our lower freq radios (below 30 MHz) would go half way around the earth but then they are cranking out much more power to do that.

Another very important factor for the max range of a system is the receiver and its initial signal reception. With everything electronic there is noise; I don't mean what we hear but rather radio frequency noise. There is ambient noise and receiver noise. There is not much you can do about ambient noise since what is out there is there and somethings are just always on. Receiver noise however can be controlled and the less there is the weaker an incoming signal can be and still be detected by the receiver. So when people look at receivers they make sure the receiver sensitivity is a low number (measured in -dB).

At our level, unless we have testing equipment (like Bruce who at least has a spectrum analyzer showing a cross section of RF), our most effective means is to ask around and compare. In a nutshell the most important numbers we are looking at will be the radio frequency (deconflicted), transmitter power (hi), and receiver sensitivity(low).



Oh my good! You seem to have loads of knowledge in that area.

So would you agree that rather than doing what I suggested with the range per Herz stuff, we could look out for how to reduce noise and then make a comparable testing/competition?
 

bicyclemonkey

Flying Derp
Mentor
I'd like to see this in it's basic form...Off-the-shelf parts that are available for online purchase, slap it in a plane, get the return to home and OSD stuff, use the radio TX/RX of choice and see how far you can go out and back.
 

JimCR120

Got Lobstah?
Site Moderator
I saw a little USB think it was plug in Spectrum Analyzer module to use with a laptop, perhaps the same one Bruce uses on RCModelReviews. It could be a good thing to reveal RF emissions in the spectrum of our intended transmissions. I think it cost about $100.

So then if the noise is generated by the on-board electronics your choices are either get new electronics or try to minimize the noise. I would be interested to see what kinds of results are produced. Sometimes the specs of components are advertised so that
you can at least know what the manufacturer is trying to sell.

I think at our level our easiest answer is to range check our stuff, make a note of the results, and then compare our findings with those of other testers, and keep our eyes open for product technical reviews. Who knows, perhaps the show would do something like that but it maybe too geeky for the masses, idk.
 

bmsweb

Site Moderator
I saw a little USB think it was plug in Spectrum Analyzer module to use with a laptop, perhaps the same one Bruce uses on RCModelReviews. It could be a good thing to reveal RF emissions in the spectrum of our intended transmissions. I think it cost about $100.

I forgot all about that video! What a great idea. I might give that a go.

We did a range test at ground level yesterday with the 5.8Ghz system (using skew planar and clover) and a stock Turnigy. On the ground we're getting easily 500meter. I was surprised with the drive back as I had the Model in the car and at 400meters away from the base station, my son said we had perfect visual.