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Old Oct 30, 2012, 07:23 PM
I think I'm inverted. Maybe.
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Aye. And we can generally count that wi-fi devices are being used facing a certain direction (right-side-up), and WiFi routers don't have big space or power limitations. We can't count as much with our planes.
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Old Oct 30, 2012, 07:27 PM
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wi-fi has very tight power limits at lest on phones and laptops
and i dont think what why up the model is means much at lest with Spektrums sat style setup
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Old Oct 30, 2012, 07:46 PM
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I suspect that is highly unlikely as 5.8 has only half the penetration of 2.4, so range will be reduced and it will be even more important to do a very careful install without masking the aerials. Not a receipe for a successful consumer product!
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Originally Posted by Elios000 View Post
wi-fi is moving to it
Maybe so, but wifi routers only need very short range (a few tens of metres max for consumer products) compared to our RC aircraft which need hundreds of metres minimum for anything but a small parkflyer. Plus the implications of losing connectivity to your router are somewhat less dire than losing control of you latest RC masterpiece...
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Old Oct 30, 2012, 07:52 PM
I think I'm inverted. Maybe.
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Originally Posted by Elios000 View Post
wi-fi has very tight power limits at lest on phones and laptops
and i dont think what why up the model is means much at lest with Spektrums sat style setup
Those are wi-fi receivers. WiFi transmitters don't have nearly the stringent requirements. Yeah, they do have hotspots now, but see how much range you get with one of those.
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Old Oct 30, 2012, 07:54 PM
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range is mostly based on power out put a 200mW RC TX is going to go a lot farther then 5mW wi-fi router

also you can get some FPV systems that use 5.8 already and they do fine out to a few miles
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Old Oct 30, 2012, 07:55 PM
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Originally Posted by acetech09 View Post
Those are wi-fi receivers. WiFi transmitters don't have nearly the stringent requirements. Yeah, they do have hotspots now, but see how much range you get with one of those.
laptop and cell phone have to transmit as well wi-fi has to have a TX and RX in both ends
so really your power reqs are much much tighter with a say a cell phone that needs to TX and RX + run the phone on effectively a 2S lipo
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Old Oct 30, 2012, 08:02 PM
I think I'm inverted. Maybe.
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Yes, they do transmit as well. I was talking about the function of the device. Effective power on receiving devices, as far as I know, is much less than most Wi-fi transmitters. Ever wondered why your cell phone isn't picking up the wi-fi signal that your laptop is, and your laptop isn't picking up the signal that your desktop's wifi card is? Routers have to be able to cope with the biggest devices, while receiving devices have to only cope with themselves.

Our cellphones run off of 1S Li-Ions mostly, these days, and only have to broadcast much shorter range signals than our RC uses.
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Old Oct 30, 2012, 09:02 PM
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Originally Posted by Elios000 View Post
range is mostly based on power out put a 200mW RC TX is going to go a lot farther then 5mW wi-fi router

also you can get some FPV systems that use 5.8 already and they do fine out to a few miles
  1. In the UK we are limited to 100mw of power for 2.4GHz TXs (http://www.ukrcc.org/35mhz.html);
  2. As far as I can tell any 5.8GHz transmitter over 25mw requires an amateur radio licence in the UK - a major issue since you need much more power to get the same range for 5.8GHz according to this: http://www.fpvuk.org/things-explaine...wer-and-range/
Based on that I can't see the RC manufacturers coming up with 5.8GHz TXs anytime soon; they wouldn't be a legal, marketable consumer product here and I suspect many other markets are similar.
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Old Oct 31, 2012, 05:15 AM
A man with too many toys
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900 MHZ may be the best solution.
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Old Oct 31, 2012, 07:56 AM
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900 MHZ may be the best solution.
Sadly not over here - 900MHz is used exclusively for 3G mobile phones. TBH I don't believe there is actually a problem to be solved at this point though; in the real world a well installed, well powered full hopping 2.4 system seems to be as near to bullet proof as you can get, at least here in the UK. If further congestion of the 2.4 band were to occur that may not hold true forever, but for now I feel 100% confident in using the band.
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Old Oct 31, 2012, 02:40 PM
Grumpy old git.. Who me?
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TBH I don't believe there is actually a problem to be solved at this point though
+1000

It doesn't matter what frequency we fly on, some people will crash their planes and blame it on "interference" or "brown-out" or "jamming" or even "triple triple secret agencies"... It's always been that way and always will be. Admitting we screwed up and crashed our plane and it was all our fault is really hard sometimes.

for example.. I'm teaching a flying buddy to fly. Twice this weekend gone I had to save the plane when "the radio stopped responding".. Soon at I touched the Tx it mysteriously started working fine Truth was he just got too slow and was flying on the verge of a stall and so the plane didn't respond to aileron input.
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Old Oct 31, 2012, 03:47 PM
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you know you could do DSMX on 72Mhz if you wanted to really
2.4 is nice because you dont need big long antennas

other then the antenna issue i wonder why they didnt do spread spectrum on the 72Mhz band? i guess it could cause issues with the older stuff
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Old Oct 31, 2012, 03:58 PM
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Originally Posted by Elios000 View Post
you know you could do DSMX on 72Mhz if you wanted to really
2.4 is nice because you dont need big long antennas

other then the antenna issue i wonder why they didnt do spread spectrum on the 72Mhz band? i guess it could cause issues with the older stuff
I don't think you can send enough data fast enough. You could with PWM, basically analog... but with digital signals I don't think it's fast enough to include all the data AND spread it.
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Old Oct 31, 2012, 09:47 PM
Freedom Isn't Free
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Hate to sound like an Old Phart, but in the '80's, we had 6 frequencies (there were a couple
reserved for licensed Ham radio guys), lots of interferance, and only 2 or 3 folks (depending on frequency) could fly at one time (cross-channel interferance).

We have come a long way and AMA deserves a lot of credit for getting us the 72 band and lately the 2.4 frequencies. Whatever the problems in the current situation, it's not as bad as it was, and IT IS UP TO US to live with the situation. AMA is making sure we aren't screwed or forgotten in the RPV field.

I think my point is that we owe AMA a lot and this is a reminder of just how much.

howell
AMA had nothing to do with getting 2.4.. All they did was bless it. The radio makers did it on their own. Thank them not AMA.
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Old Oct 31, 2012, 10:43 PM
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I don't think you can send enough data fast enough. You could with PWM, basically analog... but with digital signals I don't think it's fast enough to include all the data AND spread it.
the spread part is purely about using more then one channel ether at the same time or hoping or both

you can packetise 72 just fine ask the HAM packet radio guys about it
2.4 has a few things going for it a. its unregulated for the most part (only power restrictions) b. smaller antennas c.RC could jump right on it with spread spectrum and not interfere with older 72 gear
thinking about it wile it would work on 72Mhz it would mean stopping all use of older non spread spectrum gear as that would get shot down but the new stuff
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