antenna it would be completely uncontrolled or 'blind' using a dish or patch antenna to
receive with. Normally the best used is stick, cloverleaf or mushroom type.
For instance the probes which NASA sent out, like voyager, have no more power output
than a regular walkie talkie radio but because of the precision of the sending and receiving
'antennas' (more like a laser beam than a spotlight) it can be received from literally millions
of miles away. Of course it helps that there is comparatively little interference to swamp out
the signal in space but you get the idea.
�
If you need a graphic of this just google ‘antenna transmission pattern’ and that should
show you what I mean.
The claimed decibel (dB) increase of commercially available antennas rely on this principle
and by having a precise calibration of the antenna to the correct frequency range and
modifying the 'pattern' or focus of the transmission to give an increase in range.
In order to make your own antenna perfectly matched for optimum range you would need
to know the frequency range (bandwidth) in use and a good knowledge of antenna theory.
Unfortunately there's a really simple way of determining the signal bandwidth used by the
controller..
I say unfortunately.
It's called a spectrum analyser. Or an oscilloscope that can go up to 2.4GHz.
You hook the controller up to one and measure the maximum and minimum frequency the
transmitter uses, that gives the precise frequency range that you calibrate to the middle of.
There is a way to hack a pc usb tv stick to open the frequencies up to perform a similar
function to this as well, but I've only ever done it once. Even then it was not precisely
calibrated making the reading suspect at best, useless at worst.
The current stock antenna used is a 'naked lightbulb' type, probably poorly calibrated, but
ok for toy grade use. You can open the controller up and replace it with another better
manufactured antenna. Even if this is still a 'naked bulb' type antenna it should be better
than the stock one. It means you can use this mod to extend range, even giving is a sort of
quasi 'spotlight' antenna if you wanted to, but this means you have to point it in the right
direction
all the time
, it becomes less useful the closer you are, for instance if you do a high
speed pass in front of yourself and don't turn the antenna to face the quad all the way
along, despite being quite close, you could quite easily loose signal. Or, using the bulb
analogy again, try pointing a spotlight at a bird flying by and see how difficult it is to keep it
in the light. You want to tailor the antenna for your specific needs.
Synopsys
If you are wanting to extend range then I would stick with regular good named brand,
antennas for the controller, the fpv monitor and the quadcopter if you want reliability and
consistency. They may not be calibrated to your specific channel's frequency range but it
should be close enough to give good results.
The next step up could be getting a hobby grade transmitter that you can programme for
the CG035 frequencies and codes, but I personally don't know if anyone has been able to do
that.....yet, and a diversity receiver for FPV.
However If you want to experiment with it then thats cool too, but expect it to be a long
process with a lot of trial and error. It will certainly be an education.
Have fun!
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Elio.
