Let's talk first about specifications. Mine came with RPSMA female antenna connector (there is a MMCX version too), standard 40 channels , 25mW/200mW/500mW/800mW power switchable and 7-24V input that provide 5V output for your camera.
Weights only 7 grams without antenna and cable, and small enough to put it on any type of vehicle
New feature is Smart Audio port which allows you to change channel band and frequency and even power output via your BetaFlight OSD controller (and radio of course). If you do not have that type of controller, you can change manually all parameters with button on the VTX. 7 segment LED display shows which band is in use , number of channel and power output mode.
Another feature is PitStop mode.
What is that ? Well, for FPV racers it is good thing, when you want to change channel frequency, you put it in pitStop mode. That mode transmits with very low power output (around 0.1mW), and if you accidentally enter channel that someone is using at that moment on the race track, he won't loose his picture because of that very low output. You will see your picture but on very short range due to low output (but probably you will see someone else's picture if you enter same frequency). Excellent feature for FPV racers.
First impressions and manual setup is explained in this video:
Time to test picture quality and range. Since this VTX doesn't come with antenna, I have used FatShark antenna for VTX and Eachine EV800D googles from Banggood with their original antennas. So nothing special, no special antennas, filters, or ground station. Everything stock on Eachine googles. These googles have DVR too and I have recorded whole flight with it. I can recommend these googles for excellent picture, DVR, built in battery and splittable designt that allows you to use it as a googles or as an LCD display mounted on your radio/tripod. LINK to Eachine googles.
And what did I get ? 4 kilometres of range without any problems using 800 mW output. That is awesome, more that I will ever need.
So if you need excellent and lightweight VTX for your FPV projects, with different output modes to suite regulations in various countries, I highly recommend this one from AKK.
