Tech ! Reviews

FPV drone video transmitter (vtx) is the main force of FPV experience. Over the past few years, we’ve seen tremendous technological advances in their performance, and power output capability in units, all in a smaller and smaller form factor. Since they are installed at the multi machine end of the business, they need to be able to adapt to the space provided, be able to easily connect to power distribution boards and cameras, and be durable enough to withstand the abuse of many crashes. While installing the molds, they can easily become one of the most sensitive parts of the helicopter. Now vtx is very rich in functions. It is sometimes confusing to filter these functions, but we will introduce these functions in detail to help you clarify your internal work and help you choose the best unit for a specific application.

How does FPV drone video transmitter work?

The video transmitter uses technology similar to radio, except for a much shorter distance. At the most basic level, your onboard flight camera is connected to your video transmitter. Your camera’s job is to convert the image it captures into data, which is then sent to the video transmitter. The video transmitter converts this information into a radio signal and outputs it to an additional antenna, which then transmits the signal. A video receiver (VRx) connected to a goggle or ground station captures the signal, converts it from radio waves back to data, and displays it on the display. The range of your vtx depends very much on a number of different things; the power level of your vtx (in milliwatts or megawatts), the antenna attached to your vtx, the antenna attached to your video receiver, and the signal frequency you operate.

Note: there are no perfect settings for all situations, but there are some settings that apply to specific situations or most flight scenarios.

power output

The power output of vtx is one of the most important factors for the crew, which is usually the first consideration for the pilot when selecting. Most video transmitters for small four axis aircraft (250mm and smaller) are rated between 25MW and 800MW. The usual logic here is applicable (most of the time), when it comes to higher ratings, you can go further away from your operating base, still maintaining quality signals. The higher the level, the stronger the signal penetration (such as flying through a forest), and at a lower setting, you will experience more signal disruption. At the same time, remember that the higher the power output, the more heat vtx generates and the more energy the battery consumes. When flying at higher output, you want your multi rotor to move faster in the air so that the air moves to the crew to cool it, otherwise the vtx may overheat.

Another factor to consider is whether you plan to fly alone or with other pilots. When you plan to fly with others, multiple rotors are flying in the air at the same time. Selecting too high power output may interfere with the video signals of other pilots, resulting in signal overflow. This is definitely not an interesting situation. Imagine flying your multirotor, and everything is going well, when suddenly another pilot’s video appears in your goggles. At first, it may make you lose your sense of direction, even if it’s only for a second, and if it’s longer, it may cause your quadad to lose control and may pay for repairs in the future. That’s why many clubs have power and frequency limits in flight. When flying with a team, the recommended power output rating is usually 200-250mw, unless everyone is flying at a higher output, then you want to match your team is flying.

Frequency of FPV drone video transmitter

The operation of vtx is to broadcast your video on a specific frequency. Think of it as tuning your car stereo to a particular station; you can’t get that station unless you tune it to the right frequency. It’s the same for your vtx and VRx. In order to receive frequencies in the most stable form, both must be set to the same channel. When selecting a vtx, you first need to select a vtx that runs in the entire spectrum you are looking for. For most applications, a 5.8GHz transmitter / receiver combination is appropriate, but if you want to be remote (more than 1km), you may need to consider low frequency operating spectrum, such as 2.4GHz or 1.2Ghz.