Comparison Syma X26 vs Blade Inductrix BNF

Maximum flight time of a quadcopter on one full battery charge. This indicator is quite approximate, since it is most often indicated for ideal conditions - in real use, the flight time may be less than stated. However, by this indicator it is quite possible to evaluate the general capabilities of the copter and compare it with other models - a longer declared flight time in practice usually means higher autonomy.

Note that for modern copters, a flight time of 20 minutes or more is considered a good indicator, and in the most “long-lasting” models it can exceed 40 minutes.

Additional sensors provided in the design of the quadcopter.

— Heights. A sensor that determines the flight altitude of the machine. Such sensors can use the barometric or ultrasonic principle of operation. In the first case, the height is measured by the difference in atmospheric pressure between the current point and the starting point (that is, the sensor determines the height relative to the initial level); in the second, the sensor acts similarly to sonar, sending a signal to the ground and measuring the time it takes to return. Barometric sensors are not very accurate, but they work well at high altitudes — tens and hundreds of metres; ultrasonic — on the contrary, they allow you to accurately manoeuvre at low level flight, but lose effectiveness as you climb. However, in some advanced models, both options may be provided at once. Data from the height sensor can either be used by the quadcopter “independently” (for example, when hovering or automatically returning), or transmitted to the operator to the remote control or smartphone.

— Optical. A sensor that allows the quadcopter to "see" the environment in certain directions. One of the simplest variants of such a sensor is a downward-facing camera that allows the device to “copy” the surface under which it flies. Due to this, the machine, for example, can navigate indoors, where the signal from GPS satellites does not reach. In...addition to such a chamber, "eyes" can also be provided from different sides of the machine. Note that optical sensors have certain limitations in their use — for example, they lose their effectiveness on dark, shiny or uniform (without noticeable details) surfaces, as well as at high speeds.

— GPS module. A sensor that receives signals from navigation satellites (GPS, in some models also GLONASS) and determines the current geographical coordinates of the machine. Specific ways of using position data can be different: returning home, flying by waypoints (see below), recording a flight route, etc.

— Gyroscope. A sensor that determines the direction, angle and speed of the machine's rotation along a specific axis. Modern technologies make it possible to create full-fledged three-axis gyroscopes of very compact dimensions, and it is with such modules that quadcopters are usually equipped. On the basis of gyroscopes, automatic stabilization systems usually work, returning the car to a horizontal position after a gust of wind, collision with an obstacle, etc. At the same time, such equipment affects the cost of the device, and in some cases (for example, during piloting), automatic stabilization is more of a hindrance than a useful feature. Therefore, some low-cost, as well as advanced aerobatic quadcopters, are not equipped with gyroscopes.

The range of the drone is the maximum distance from the control device at which a stable connection is maintained and the device remains controlled. For models that allow operation both from the remote control and from a smartphone (see "Control"), this item indicates the maximum value — usually achieved when using the remote control.

When choosing according to this indicator, note that the range is indicated for perfect conditions — within line of sight, without obstacles in the signal path and interference on the air. In reality, the control range may be somewhat lower; and when using a smartphone, it will also depend on the characteristics of a particular gadget. As for specific figures, they can vary from several tens of metres in low-cost models to 5 km or more in high-end equipment. At the same time, it should be said that the greater the range of communication, the higher its reliability in general, the better the control works with an abundance of interference and obstacles. Therefore, a powerful transmitter can be useful not only for long distances, but also for difficult conditions.

The frequency used to communicate between the aircraft and its control device (usually a remote control).

Some time ago, devices with analog control at a frequency of 27.145 MHz and 40 MHz could be found on sale. However, today these standards have practically fallen out of use and modern copter drones mainly use digital communications at a frequency of 2.4 GHz or 5.8 GHz(and some models support both of these ranges at once). This type of control has a number of advantages over analogue control. Firstly, it is less sensitive to interference: on an analog channel, a drone can mistake possible interference for a command and make an unexpected maneuver, while distortion of digital data is perceived precisely as distortion and does not affect the operation of the device. Secondly, the digital format provides high bandwidth, allowing you to even broadcast high-definition video directly from a drone. Thirdly, with this control, each “remote control-copter” pair is automatically allocated its own communication channel, and the system first checks whether it is being used by another pair of devices. Thanks to this, several devices can operate in close proximity without interfering with each other.

As for the features of specific frequency ranges, they are as follows:

- 2.4 GHz. The most popular standard in modern drones. This is due, on the one hand, to low cost (with all the advan...tages of digital control), and on the other hand, to expanded compatibility. The fact is that 2.4 GHz is the most common range of Wi-Fi modules in smartphones, tablets, etc.; so compatibility with this range allows you to easily supplement the drone with the ability to control it from an external gadget (however, this capability is not mandatory). One of the disadvantages of 2.4 GHz is also associated with the abundance of devices that use this frequency: in addition to Wi-Fi, these are Bluetooth modules, some other electronic devices, as well as most remote controls for radio-controlled equipment (not just copters). So this range is somewhat inferior to the 5.8-GHz range in terms of noise immunity; on the other hand, even with a busy broadcast, this moment is extremely rarely noticeable.

- 5.8 GHz. Further, after the 2.4 GHz described above, the development of digital standards. Allows for a longer communication range and is also more reliable, since there are significantly fewer extraneous signal sources at the 5.8 GHz frequency. In addition, the increase in frequency made it possible to increase bandwidth and effectively broadcast HD video from copters in the most advanced standards. However, some of the newest Wi-Fi standards also include support for this range, so drones in this category can also allow control from a smartphone (however, in such cases it is worth paying special attention to compatibility). The disadvantages of this option include the relatively high cost; however, thanks to the development and cheaper technology, support for 5.8 GHz can now be found even in relatively inexpensive copters.

- 2.4 GHz and 5.8 GHz. Support for both ranges described above - as a rule, with the ability to use any of them, at the user's choice. This provides additional convenience, reliability and versatility. For example, a model with two control methods (see “Control”) can use the 2.4 GHz band when working with a smartphone (which ensures a minimum of compatibility problems), and work with a remote control at 5.8 GHz (for maximum range and reliability). And drones controlled only from a remote control may even have a function such as automatically scanning ranges and selecting the least loaded one. At the same time, dual-band models are slightly more expensive than single-band ones, but the difference in price (especially with devices only at 5.8 GHz) is not particularly significant. So most modern copters capable of operating at a frequency of 5.8 GHz fall into this category.

When using specialized communication protocols, control signals between the copter and the remote control can be transmitted at special frequencies: 720 MHz, 915 (868) MHz.

The number and type of batteries used in the quadcopter control panel.

— AA. Replaceable batteries, colloquially known as "AA batteries". They are available not only in the form of disposable batteries, but also in the form of rechargeable batteries, are produced under various brands that differ in price and quality (which provides freedom of choice), and finding such elements on the market is usually not a problem. The power and capacity of AA elements are relatively small, but in most cases they are quite enough for normal operation of the transmitter for quite a long time. Usually, modern consoles require several of these batteries; in the most high consumption this number can reach 8.

— AAA. Also known as "pinky". In fact, a smaller version of popular AA elements (see above); has the same key features, but differs in more compact dimensions and, as a result, somewhat reduced power. This option is typical for low-cost class models, with a small range of the remote control.

— 3s. This marking does not describe the size of the battery, but its operating voltage and technology. It denotes a lithium-ion or lithium-polymer battery (see "Battery type"), assembled from three cells with a standard voltage of 3.7 V each, and thereby delivering an operating voltage of 11.1 V. The advantages of such a power supply are high power and capacity, which allows you to use the remote control for a long time without recharging. At the same time, batteries of thi...s type can vary significantly in size and weight, and not every model marked 3s will be compatible with the remote control. In addition, finding a spare battery is more difficult than a set of cells of a standard size.

— Proprietary battery. Powered by an original battery that is not related to any of the options described above. Such batteries can be much more powerful than replacement cells, making them well suited even for remotes with high power consumption. Their main advantage is the difficulty with quick replacement: the design of the remote control is at best poorly suited for this, and at worst the battery is generally non-removable. Also, finding the right replacement battery can be a major hassle.

The name of the engine installed in the quadcopter. Usually, knowing this name, you can easily find information about the features of the engine — both official manufacturer data and reviews from users — and determine how much you are satisfied with its characteristics. This can be very important when choosing a high-end professional model.

The capacity of the battery supplied with the quadcopter.

Theoretically, a larger battery can provide a longer charge time. However, keep in mind that this time also depends on the power consumption of the copter — and it is determined by the power of the engines, dimensions and weight, as well as a number of other features. In addition, the actual battery capacity is determined not only by ampere-hours, but also by its nominal voltage. Therefore, only quadcopters with the same battery voltage and similar operating characteristics can be compared by amp-hours; and it is best to evaluate battery life by directly claimed flight time (see below).

General dimensions of the device. A fairly obvious parameter; we only note that for models with a folding structure (see above), in this paragraph, the dimensions in the working (unfolded) position are given, and the dimensions in the folded form are specified separately.