Today I will review a super light VTX module for FPV drones. Weighting only 3.5g, the Eachine ATX03 is suitable for small sized quadcopters.
VTX modules are used to wirelessly transmit the camera’s video signal. The most common frequency for FPV is 5.8Ghz. In order to allow the use of multiple VTXs in the same time (such as during a drone race) the frequency range (5333MHz~5945MHz) is divided into individual channels. Versatile VTX modules like this Eachine ATX03 features up to 72CH transmission channels.
According to transmission power you can find VTX modules from 25mw up to 10W. While proximity FPV park flying requires less power (25mw is just good for most cases) long range FPV flights (1 – 10Km) requires high TX power. Output power can be fixed or switchable between multiple values like in the case of Eachine ATX03. Note: always check the local RF regulation when you choose a VTX.
In order to save weight, like in the case of Eachine TX03, the VTX modules are integrated into the camera.
Eachine ATX03 VTX key features
- Adjustable output power (0/25mW/50mW/200mW);
- 3.2-5.5V input voltage (suitable for 1s Li-Po);
- NTSC and PAL video standards;
- Audio line input (10 KΩ impedance);
- 9 bands with total of 72 channels (including Raceband);
- 7 segment status display;
- One button configuration;
- IPEX antenna with connector;
- Very compact (size of 21.43mm * 15.20mm).
Eachine ATX03 VTX review
Disclosure: I received this Eachine ATX03 VTX as part of a product review collaboration with Banggood. Although the product was offered free of charge, all opinions in this review are my own.
The ATX03 VTX comes in a small box together with the instruction manual. Power wires as well as the camera wires are soldered. The 5.8G IPEX antenna is attached to the mainboard through a MHF RF Mini connector.
The VTX module has the size of 20mm x 17mm and weights about 3.5g including antenna.
Eachine ATX03 pin out / wire coding
- Red – power out for camera;
- Black – ground / GND;
- Yellow – Video In;
- White – Audio In;
- There is no 5th wire as the user manual says.
On top of the ATX03 5.8G VTX is located a micro push button which allows to configure the VTX. While short pressing the button you can change the channel number (from 1 to 8), by long pressing you can toggle between bands (A,b E, F, r, U, o, L and H).
Output power can be changed by pressing the same button for more than 5 seconds. You can toggle between 0mW, 25mW, 50mW and 200mW.
The actual settings are shown on the 7-segment display. BTW, configurations are stored on a non-volatile memory, so you don’t need to reconfigure the VTX every time you’re powering on.
Eachine ATX03 review – Test
In order to test the VTX, I used my RunCam Owl Pus camera, a 3.7V Li-Po battery and a 7″ FPV monitor.
Unfortunely Eachine doesn’t include with the ATX03 a 4 to 3 pin adaptor cable. This would allow to directly use the VTX with audio-less cameras without any modification (soldering).
Setting up the Eachine ATX03 VTX is very simple. I like the “one button” approach.
Range is excellent even at 25mW. In my opinion you don’t need to set higher output power for park flying. Don’t forget that increasing the broadcast power will put more stress to the flight battery.
I didn’t tested the audio carrier but I’ve read from other fellows that is a bit noisy.
For those who are interested in a lightweight and cheap VTX, this ATX03 can be ordered from here. I recommend to order together with the VTX a “Y” power cable in order to avoid soldering.
- Very lightweight;
- Adjustable broadcast power;
- 5V output for camera (with voltage booster, works even with 1s Li-Po);
- Audio Line-in for FPV with sound;
- Easy to configure.
- Not included adapter cables. In most cases requires soldering.