Looking for long range 5.8GHz video transmitter? Check out the AKK FX2 and X2 Ultimate 1200mW VTX! They are also capable of transmitting at 25mW and 200mW, so you can use it for indoor flying as well as racing with others outdoor.

Specifications

The AKK X2 and FX2 VTX’s have the same spec, apart from the form factor (dimension) and weight.

Input Voltage: 7V to 26V

Output Voltage (BEC): 5V / 500mA (designed for FPV camera only)

Supports Smart Audio (VTX Control)

Supports Pitmode

Output Power settings: 25mW, 200mW, 600mW, 1200mW

Antenna connector: MMCX

Built-in Microphone

Connection: 6-pin connector

X2 dimension: 22x32x8mm; Weight: 6.8g

FX2 dimension: 36x36x5mm; Weight: 9.6g

What’s improved from the old version?

The “Ultimate” is an upgrade to the previous FX2 / X2 VTX. The improvements include:

Higher maximum output power (1200mW vs. 800mW)

Support for 6S LiPo (26V vs. 24V)

Beefier 5V BEC (500mA vs. 300mA)

Upgraded microphone

15%-20% lighter in weight (roughly)

X2 is now equipped with MMCX rather than SMA

However the “ultimate” is $7 more expensive than the “non-ultimate” version. So you might want to consider the cheaper FX2 / X2 if you don’t use 1200mW, or 6S :)

AKK FX2 Ultimate VTX

The AKK FX2 VTX is designed to be mounted in the FC stack (30x30mm mounting holes). It has a MMCX connector, a push button to change VTX channel, band and power, and a single digit display.

All the components are built on the top of the PCB, there is nothing on the underside. This makes a thinner board and easier to install in the stack.

The package comes with a MMCX to SMA pigtail, and a silicone cable for the power and signal.

AKK X2 Ultimate VTX

The AKK X2 is in a smaller form factor, so you can install it anywhere in the frame. If you don’t plan to install the VTX in the FC stack (e.g. in an ultralight build there is no room), then you probably want to get the X2 instead of the FX2. It’s a few grams lighter too.

Same as the FX2, the X2 has a MMCX connector, a push button and a single digit LED display.

The X2 VTX comes with a MMCX to SMA pigtail, and a silicone cable for the power and signal.

Here is the manual describing the operation of the VTX.

Actual Output Power Testing

I tested the actual output power of both FX2 and X2 Ultimate VTX using the ImmersionRC power meter V2 on all 8 Raceband channels (see all 5.8GHz bands and channels).

FX2 Ultimate

R1 5658 R2 5695 R3 5732 R4 5769 R5 5806 R6 5843 R7 5880 R8 5917 25mW 12.9 18.7 25.1 27.6 33.7 38.7 40.0 37.2 200mW 205 224 245 233 266 289 277 240 600mW 550 590 605 561 540 595 555 545 1200mW 870 840 960 800 800 870 860 730

X2 Ultimate

R1 5658 R2 5695 R3 5732 R4 5769 R5 5806 R6 5843 R7 5880 R8 5917 25mW 21.3 25.5 30.5 30.9 33.2 36.9 36.9 33.9 200mW 235 232 253 211 214 227 266 229 600mW 546 574 607 535 600 630 522 505 1200mW 1040 920 900 900 1030 1020 1000 872

Do you really need 1200mW?

Theoretically, higher power help increase maximum range of your VTX, but there are many other factors that can also affect your range. Not to mention higher VTX power can introduce some potential problems.

To maximize range, VTX power is probably the last thing on my list. You should optimize other parts of your FPV setup first. Using suitable FPV antennas for both transmitter and receiver, and getting a diversity/multiversity video receiver are just as important.

One downside with high transmitting power is multi-path interference, especially when you’re flying in environment such as rocky terrain and cliffs. Your VTX also gets much hotter which can affect the performance of the transmitter without adequate cooling. When I was testing the VTX on the bench, I noticed the power drops considerably over time if there is no cooling, and it gets really, really hot, so that’s something you should beware of.

Most importantly, you should follow your local regulation regarding the maximum power you are allowed to transmit. Be responsible and don’t break the law.

Audio Quality

I haven’t tested audio in a quad yet, but I briefly tested it on the bench and it sounded quite noisy. The static noise is really loud to the point I can barely hear myself when talking to the mic.

But hey, at least the mic is working this time! It wasn’t working with the older FX2 and X2 when we tested it last time.

Pitmode

There doesn’t seem to be anyway you can enter or quit Pitmode using the button. The only way to enter or quit Pitmode is by using Smart Audio (VTX Control).

VTXTable

Here is the VTXTable for setting up SmartAudio.