You here a lot of people talk about diversity controllers, whats all that about then ?
Diversity is a means of comparing two or more received signals from the FPV plane and picking the best signal from the ones available to display in your goggles, on your screen or to decide which signal to send to your antenna tracker.
There is two different ways currently of doing this. The first method is to monitor a voltage in each receiver unit and comparing them. The stronger of all the signals in theory is the best picture and this is chosen by the diversity controller
The second system use by the Oracle system actually compares the pictures themselves and pick the best one to pass on. Each have their own merits, but essentially do the same job.
You can buy stand alone controllers such as :
Oracle here :
At a price of around £150 its not a cheap bit of kit but does the job very well indeed.
Another option is a Duo receiver. Its called a Duo because it has two antenna inputs and compares inside the receiver then output the one best signal.
Here’s a Dual input receiver the ImmersionRC Due 2400 :
Priced around the £ 190 mark again not cheap but very good.
If you have some electronics and soldering skills you can go down the DIY diversity route. A few examples are available to build and are reported to be very successful
So that’s the controllers, what decides how good each picture is ?
Well that’s down to your receiver antenna choice. The choice is yours, you can mix up any selection you want. You can have an Omni on one input, a patch on the other. Maybe a Patch on one, maybe a Yagi.
So whats the point ?
Well its for getting the best from your system at all times. One antenna may excel in one way but lack in other, so you can use multiple antennas at the same time.
Here`s a few examples of its use :
Lets say you have a simple two antenna input diversity system.
One antenna could be an Omni antenna the other could be a circular polarized patch antenna. When your flying behind you the omni would have a better reception and the diversity would pick that.
When the plane is in front of you a bit far out for the Omni the patch`s signal would be better so it will puck that one instead.
If you bank the aircraft then the Omni would be out of polarization so the Circular Polarization would provide the better picture.
You could have bought a diversity Patch antenna, these are one single Patch antenna housing but contain 2 antennas inside. They have one mounted vertically and the other mounted horizontally. Two wires come out of it, one for each antenna.
You plug one wire into each of the diversity inputs. When the plane is flying level, away and towards yourself the vertical antenna will receive the better signal, in maneuvers or banked turns the vertical will. The diversity see`s which is best so you get the best from the two.
So what if i have more than 2 inputs ?
If your diversity system has more than 2 inputs the worlds your oyster. You can combine the best of all worlds and have as close to perfect as you can get.
An example of this would be say a 8 dbi Circular Patch, combined with 2x Yagi antennas of 16 dbi. Then your circular could do all the closer range receiving, being circular the orientation of the plane wouldn`t matter, then at longer ranges the vertically mounted Yagi would be chosen then on banked turns the horizontally mounted Yagi.
This sort of system as most with the diversity systems are normally used with an antenna tracker to point the higher gain antennas at the plane. Some choices though don’t need this.