Quick Answer
VTX power output determines how far your video signal reaches. Lower power (25mW) is used for racing and close-range flying, mid-range (200-600mW) suits freestyle and general flying, and high power (1W+) is for long-range and dense environments. The 5.8GHz band is standard for analog FPV video in most countries.
What Is a VTX?
A VTX (video transmitter) sends the live camera feed from your drone to your goggles. It operates on the 5.8GHz ISM band for analog FPV systems. The power output, measured in milliwatts (mW), directly affects how far and how strongly the video signal travels. Higher power means better range but also more heat, battery drain, and potential interference with other pilots.
Common VTX Power Levels
| Power | Approximate Range | Best For |
|---|---|---|
| 25mW | 100-300m | Racing (legal limit in UK/EU), indoor, whoop |
| 200mW | 300-800m | Freestyle, general flying |
| 600mW | 500m-1.5km | Freestyle with good antennas, medium range |
| 1000mW (1W) | 1-3km | Long range, wooded areas, fixed-wing |
| 1600mW+ | 2-5km+ | Extreme long range, high-gain antennas needed |
These figures assume open line of sight with good antennas on both ends. Buildings, trees, and ground absorption all reduce effective range significantly.
Legal Limits
In the UK and most of the EU, the legal limit for 5.8GHz transmission is 25mW EIRP. This applies to all analog and digital video systems. Many pilots fly at higher power levels, but you should be aware that doing so may breach regulations and could cause interference with other spectrum users. Race organisers typically enforce 25mW limits for competitions.
25mW: Racing and Compliance
Running at 25mW keeps you legal and avoids causing interference with other pilots at a fly-in or race. Modern VTX units like the RushFPV Max Solo produce surprisingly clean output at low power, which can look better than a cheap VTX running at 600mW. For whoop and indoor flying, 25mW is more than enough to cover the distances involved.
200-600mW: Freestyle
Most freestyle pilots run between 200mW and 600mW. This power range provides a solid signal for typical flying distances (a few hundred metres) without excessive heat. The AKK Alpha 4 VTX offers adjustable power from 25mW up to 4W, giving you the flexibility to switch between race-legal low power and long-range high power from the same unit.
1W and Above: Long Range
High-power VTX units are designed for long-range flying where you need to maintain a video link over a kilometre or more. The Rush Tank 1600mW VTX is a proven choice for long-range builds. At these power levels, antenna selection matters enormously. A good directional antenna on your goggles (patch or helical) paired with omnidirectional antennas on the drone will extend range far more than simply increasing VTX power.
VTX Power vs Antenna Quality
Many pilots make the mistake of turning up power when their video breaks up. Often, the real problem is antenna quality or placement. A low-quality antenna will waste most of your transmit power as heat rather than radiated signal. Upgrading to a quality circularly polarised antenna on both your VTX and goggles will make a bigger difference than doubling your power output. The antennas collection has options for every budget and build size.
Battery Drain and Heat
Higher VTX power draws more current. A VTX at 1W might draw 500mA or more from your 5V BEC, which adds up over a flight. On small whoop builds where every milliamp counts, sticking to 25mW saves meaningful flight time. Heat is also a concern: VTX units running at high power get hot, and if mounted near your flight controller or ESC, that heat can cause reliability problems. Ensure adequate airflow around your VTX, especially at 600mW and above.
Pit Mode
Most modern VTX units include a pit mode that transmits at an extremely low power (around 0.1mW) for bench testing without causing interference. Use pit mode when setting up your drone at a flying field to avoid disrupting other pilots. Your goggles will pick up the signal at close range, but it will not interfere with anyone flying.
Troubleshooting Video Signal
If your video is breaking up despite adequate VTX power, check your antenna connections, ensure your VTX and goggles are on the same channel and band, and verify that your camera is outputting a clean signal. Our FPV video signal troubleshooting guide covers common causes and fixes. For more on how frequency bands and channels work, see our FPV frequencies and channels explained article.