So I have been wondering if I could stick a Dragon-Link on my favorite Devo6 radio... answer was no..
But it turns out things are not as complicated as it seems, because your 2.4G radio system is living in the same spectrum as WiFi routers.. Seems you can take the 2.4G output and simply plug it into a WiFi Antenna booster..
And 3D Robotics sell a fine $55 WiFi booster for exactly this.
Click through for build pictures and parts links.
It all started with me looking high and low for a official booster kit for the Devo radios, I love the little Devo6 for FPV, it is much more comfortable than some of my big radios for comfortable flying, but it only fly out to about maybe a mile, misunderstand me right, that is a lot of distance and I rarely need more.
The problem is that the 1 mile distance is up in the air clear of obstacles etc. if you fly low, it is easy to get a bunch of "stuff" between yourself and the aircraft, suddenly that 1 mile range is reduced to 1/4 mile and next thing you know.. you are crashing. that is why sometimes its worth boosting the antenna output.
So knowing that I was looking for more power, a friend of mine send me this article from DYIdrones.com where Jordi Munoz explains how he installed the booster to his radio.. seems like that would work for me as well, after-all the Walkera DEVO radios are also 2.4G systems.
Seems you need the booster from 3D robotics and maybe also a voltage regulator to give clean 6v power for the booster from a 2S battery you can mount on the back of the radio as well. Hobby King have one here. Im tempted to plug the booster into the power from my Devo and simply swap the 2S Devo battery more often.
Here is a alternative smaller booster "only" 500mw, keep in mind your radio at max setting is 100mw so this is still 5 times the power you are used to and may be fine locally.
OK nuf digressing, I got the box from 3D robotics today.. ripped it open and the girls in customer service was quite amused with my joy in a grey thing with a antenna. (I DID have grand plans of a build video.. but sorry had to plug it all together.. so here is instead the description after the fact.)
I should admit to being hugely worried about my cracking my favorite radio open and messing with its guts. this really is not my comfort area, however it turned out that getting the antenna cable connected correctly really was the biggest part of this project, next to getting all the screws back in the case correctly.
Good News, I found a couple of cables in the drawer with the right plug in each end. to attach to the Devo antenna out plug and to the extension cable for the booster.
I fretted a bit about how to bring the cable out.. maybe I should just pull it out the little door behind the TX on the Devo6.. in the end I drilled it into the top shoulder of the Devo6 and attached the WiFi booster with a double layer of 3M industrial double-side tape.
The trick became organizing the cable to avoid hard-turns in the coax cable.
Im not claiming this is a perfect cable run, and am looking to find a short cable that can go directly from the Devo Antenna out to the booster.
The final issue was powering the booster. it nominally require 6v DC. and I first thought to snag the power from the Devo battery.. but since I do not yet have a feeling how fast this thing empties batteries, I instead added a JST plug to the cord I cut from the official wall adaptor. and put a bit of velcro for holding a 2S battery.
Im not done testing this thing. But basic math suggest that to double the reach one need to qua-double the power (roughly) so that would mean this gets me conservatively 2 to 2.5 times the reach I used to have (going form 100mw to 1000mw).. not exactly Dragon-Link distances. But should give me a good deal more confidence in my signal bumming around in the forest flying proximity.
I have been using a 8turn helical IBcrazy antenna pointed by the spotter.. and have flown out of control range a few times where RTH suddenly took over while I had great video.. hopefully the control can now out-reach my video again.
Improvements.. well plenty.. for starters, I would like to wire the booster to the Devo battery and think I will put a extra switch for booster ON-OFF on the radio. it seems to be a through booster as I have no problems flying LOS locally without turning on the actual booster. I did do a quick range test with the booster on and off.. by binding the quad. and setting props to 10% throttle.. then walk away until the thing loose signal and stop running. I used a bunch of concrete walls we have handy.. no booster did not go to far, but with the booster I got quite a lot further... so not scientific.. but it seems to work.. not bad for about $55 DYI project really.
Little help here..... ;-)
How long can I safely run the 1000mw (1 watt) booster on a 2S 1000mah battery?
UPDATE WARNING and ADDITIONAL INFO TO READ.....
OK a week+ of flying this concept have shown a couple of things..
1. multiplying the output on the antenna do not double the actual range. you will have more coverage, but don't expect to go flying miles downrange just like that.
2. one of my friends who is a RF engineer (and a damn fine one at that) explained to me, that most of these amplifiers are rather shitty, and add a lot of noise to the amplified signal, so even tought its stronger, its not readable and meaningful as far as the signal goes.
3. you can find the 3Drobotics booster on Amazon in the $40 range.
4. IF you REALLY want distance.. pick up a ImmersionRC ezUHF box TODAY for about double the money you spend on the 3D robotic's kit.
1000mw WiFi booster from 3D robotics
*Yes I stuck the 3D Robotic's logo on the box. its really a ARGtek wifi booster.
I got the 1000mw WiFi booster from 3D robotics