Comparison iFlight Chimera7 ECO 6S vs FLH 7" 5.8G 2.5W ELRS 915MHz

The diagonal distance in inches between opposing drone motors. Aircraft with frame sizes less than 7 inches are conventionally classified as Micro, while those with frames 7–8 inches and 9–10 inches are included in the Mini category.

The size of the frame directly affects the maximum diameter of the propellers, in inches, that can be installed on the drone. If the copter is built on a 7-inch frame, then the permissible diameter of the propellers for it will also be 7”.

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.

The highest speed that a quadcopter can achieve in horizontal flight. It is worth considering that in most cases this parameter is indicated for optimal operating conditions: a fully charged battery, low air temperature, minimum weight, etc. However, it is quite possible to rely on it both when choosing and when comparing different models of copters with each other.

Note that quadcopters were originally designed as stable and maneuverable aerial platforms, and not as high-speed vehicles. Therefore, you should specifically look for a fast quadcopter only in cases where the ability to quickly move from place to place is critical (for example, when the device is supposed to be used for video recording of fast-moving objects over large areas).

The weight that the quadcopter is capable of carrying while performing its functions. By payload we usually mean the equipment that the aircraft carries directly without compromising flight stabilization: thermal imagers, cameras, rangefinders, release systems, etc. The higher the payload, the more diversification of missions a drone can accomplish per flight.

Possibility of online video broadcasting from the quadcopter to an external device — smartphone, laptop, control panel with display, virtual reality glasses, etc.

This feature provides several benefits at once. Firstly, it greatly simplifies the control of the device, even if it is within sight; and if the copter is not visible from the ground (which happens often, especially when using heavy professional equipment), then it is very difficult to do without "eyes on board". Secondly, live broadcasting makes it possible to use a drone for real-time observations, as well as full-fledged aerial photo and video shooting; recording of footage can be carried out both on an external device that receives the broadcast, and on the aircraft’s own carrier (usually a memory card — see below).

The specific features of the live broadcast for each model should be clarified separately; however, nowadays, thanks to the development of technology, such an opportunity is available even in low-cost devices.

The control method provided in the copter.

Modern drones are usually controlled by a remote control, a smartphone, or both. Here is a detailed description of each of these options:

— Remote control only. Management carried out exclusively from the complete remote control. The most common option, found in all varieties of drones — from the simplest entertainment models to high-end professional devices; and heavy commercial / industrial models (see "Type") are completely controlled exclusively in this way. Such popularity is explained by two points. Firstly, the functionality of the remote control can be almost anything — from a small device with a couple of levers and buttons to a multifunctional control unit with a screen for live broadcasts and displaying various specialized information. Thus, the equipment of the remote control can be optimally matched to the features of a particular copter. Secondly, you can install a powerful transmitter with a large range in the remote control (whereas the range of smartphones is very limited, and it also depends on the specific gadget model). Well, besides, the control panel is initially supplied with the drone (except that the batteries in some models need to be purchased separately).

— Smartphone only. Management carried out exclusively from a smartphone (or other similar gadget — for example, a tab...let) through a special application; communication is usually carried out via Wi-Fi. This option is good because almost any functionality can be provided in the control application; and the copter itself turns out to be convenient in transportation — in the sense that you do not need to carry a separate remote control with it. However, the range in such a control is very small — even under perfect conditions, it usually does not exceed 100 m, and in some models it does not even reach 50 m; and the actual communication range also strongly depends on the characteristics of the control gadget. In addition, the controls on the touch screen are not tactile, making blind control almost impossible. As a result, this option is very rare — in certain models of mini-drones and selfie-drones (see "In the direction"), for which the absence of a remote control and ease of carrying are important, and the described disadvantages are not critical.

— Remote control and smartphone. The ability to control the drone both from the remote control and from a smartphone. The features of both options are described in detail above; and their combination is found mainly in relatively simple devices, for which the shortcomings of control via a smartphone are not critical (although there are exceptions). At the same time, the main option for such copters is often control from an external gadget, and the remote control may not be included at all; This point does not hurt to clarify before buying. However, anyway, this control format gives the user the opportunity to choose the best option for a specific situation. For example, for recreational flights during a "sally" in nature, you can get by with a smartphone, and for aerobatic training, a remote control is better. So most modern quadcopters that can be controlled from a smartphone / tablet fall into this category.

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 frequency of the radio channel used to transmit the video stream from the camera on board the drone to the receiving device: smartphone or tablet, control panel or pilot’s video glasses. The most common frequencies are 2.4 GHz and 5.8 GHz; video data transmission at a frequency of 1.2 GHz is less common. This parameter directly affects the quality and stability of the video signal, depending on environmental conditions, as well as accompanying interference from other devices. Thus, for receiving video from FPV drones, the most preferable frequency is 5.8 GHz, which is due to a wide selection of channels and high data transfer rates.

The diameter of each individual quadcopter/multicopter propeller (it is usually the same for all propellers). In general, this indicator is of secondary importance: it is selected by the manufacturer in such a way as to provide features corresponding to the class of the machine. We only note that the noise level may depend on the size of the propellers: all other things being equal (the number of propellers, the number of blades, the weight of the apparatus, etc.), a propeller of a smaller diameter must rotate faster to provide the necessary thrust, and at high speeds the engines also run louder.