Comparison Sencor SRD 7200 vs Sencor SRD 215

A type of tuner used in radio receivers.

- Analogue. Tuning to the desired frequency in such tuners is carried out using the wheel. This scheme is considered more convenient than digital trim (see below), but the accuracy of analogue regulators is lower. This can make it difficult to use the receiver with numerous stations in a small frequency range (especially for FM broadcasts in large cities). In addition, the analogue tuner "does not know how" to memorize stations.

- Digital. The direct tuning of the tuner in such receivers is performed by an electronic circuit; the user only sets the desired frequency using the increase / decrease buttons or, in advanced models, from the numeric keypad. These tuners are somewhat less convenient for manual tuning, but they do a good job of fine tuning. Also, many receivers with digital tuners have the function of storing stations (see "Station Memory"), automatically searching for all available stations, etc.

— FM. The most popular broadcasting range among radio listeners today is primarily due to the fact that the vast majority of music stations broadcast in it. This is due to its features: FM uses frequency modulation, which makes it possible to broadcast sound with a fairly high sound quality, and even in stereo format. In the frequency band, the term "FM" usually refers to the 87.5 MHz to 108 MHz portion of the VHF band, although the range of individual receivers may vary. The disadvantage of FM is the limited range — within the line of sight (up to several tens of kilometers), which has secured the reputation of "urban" stations for FM stations.

— AM. Formally, this designation is not a range, but a type of modulation: "amplitude modulation" — amplitude modulation. In consumer radios, AM most often means the medium wave range of about 520-1610 kHz. Such waves have a propagation range of hundreds of kilometers, but the sound quality in this case is somewhat worse than that of FM, and therefore the AM band is mainly used by radio stations of the “conversational” genre (for example, news or journalistic).

— SW. Broadcasting on short waves (short wave) in the general range from 2.5 MHz to 26.1 MHz, divided into a number of separate sub-bands. Sound quality is average. Short waves are able to reach the opposite side of the Earth, but immediately outside the line of sight of the transmitter, a “dead zone” is formed, several...tens of kilometers wide. As a consequence, SW is commonly used for overseas broadcasts.

— DAB. Abbreviation for Digital Audio Broadcasting, i.e. "digital broadcasting". This term describes the key difference between this range and those described above: broadcasting in it is carried out not in analogue, but in digital format, the MP2 codec is used for transmission. This gives a number of advantages over traditional transmitters — in particular, a greater range with less power and high quality of the broadcast sound. In addition, this sound is practically not subject to distortion: weak interference does not affect its quality, and when the transmitter power is critically reduced, the signal is not distorted, but disappears entirely. The latter, however, can be written down as disadvantages; but the really significant drawback of this option is perhaps its low prevalence (so far) in the CIS countries. Technically, such broadcasting can be carried out in any band above 30 MHz, but in fact several options are used (depending on the country) related to the VHF band.

— DAB+. An updated and improved version of the DAB standard described above. It has all the characteristic features of digital broadcasting, and differs from its predecessor in higher sound quality at the same bit rates — both due to the use of a different codec (HE-AAC v2), and due to the use of more advanced noise correction algorithms. DAB+ broadcasts cannot be received on DAB receivers: at best, this will require a firmware update, and at worst, you will have to change the receiver itself.

Number of stations, i.e. certain fixed frequencies, which can be stored in the receiver's memory. This greatly simplifies tuning: by fine tuning the frequency once, in the future you can turn on the desired station by simply selecting it from the list (and in some models, it is enough to press a separate button once). The memory is usually found in receivers with a digital tuner (see "Tuner type").

The Radio Data System RDS technology is used primarily in the FM band; it allows, in addition to the sound signal, to transmit additional textual information by radio — for example, the names of broadcast compositions, announcements, advertising messages, etc. Accordingly, to display this information, the radio receiver must be equipped with a display.

— Bluetooth. Wireless technology for transmitting sound from mobile phones, tablets, etc. Allows you to connect a device wirelessly at a short distance from the signal source. The quality and overall capabilities of Bluetooth vary depending on the version:

— Bluetooth 4. Each version brings improvements relative to the previous one. So in version 4.0, three standards were actually combined: traditional Bluetooth, a high-speed channel and an energy-saving mode for small amounts of data. This allowed us to optimize channel usage and battery consumption. In version 4.1. Noise immunity has been enhanced when working next to 4G LTE modules. And version 4.2 introduced mainly general improvements in speed and security.

- Bluetooth 5.0. One of the most important innovations of the Bluetooth 5.0 standard is the expansion of the capabilities of the BLE (Bluetooth Low Energy) mode: if necessary, the device can increase the range by reducing the speed, or speed up transmission by reducing the range. In addition, a number of improvements have been introduced regarding simultaneous work with multiple connected devices.

- Bluetooth 5.1. A significant upgrade in version 5.1 was the ability to accurately position the signal transmitter (receiver). If previous versions could only determine distance, then version 5.1 can also determine direction. Thus, navigation began to function better and more accurately, which improved wo...rk with the smart home system, searching for connected devices, etc. In addition to this, the improvements again concerned saving energy consumption and simultaneous work with several connected devices.

- Bluetooth 5.2. The next update, after 5.1, is Bluetooth 5th generation. The main innovations in this version are a number of security improvements, additional optimization of power consumption in LE mode and a new audio signal format for synchronizing parallel playback on multiple devices.

- Bluetooth 5.3. The Bluetooth v 5.3 wireless protocol was introduced at the dawn of 2022. Among the innovations in it, they accelerated the process of negotiating a communication channel between the controller and the device, implemented the function of quickly switching between the operating state in a low duty cycle and a high-speed mode, and improved the throughput and stability of the connection by reducing susceptibility to interference. When unexpected interference occurs in Low Energy mode, the procedure for selecting a communication channel to switch from now on has been accelerated. There are no fundamental innovations in protocol 5.3, but a number of qualitative improvements are evident in it.

- Bluetooth 5.4. The version was presented at the beginning of 2023, the range and data exchange speed were increased. Also in Bluetooth v 5.4, the energy-saving BLE mode has been improved. This protocol uses new security features to protect data from unauthorized access, has increased connection reliability by selecting the best channel for communication, and prevents connection losses due to interference.

— USB port. The presence of a USB connector allows you to connect a flash drive, mobile phones, MP3 players and other similar peripherals. Accordingly, such models have a built-in player and allow you to use connected gadgets exclusively as a drive.

- Card reader. Like the USB described above, this item implies the presence of a built-in player. And the card reader allows you to use memory cards as a drive on which songs will be recorded.

— Line input. Input for transmitting audio in analog format. Through this input, you can connect an external signal source to the radio - for example, an MP3 player - and listen to music through the receiver's speakers. Despite the development of digital standards, line input is still one of the most popular connection interfaces.

The maximum power output of the receiver speaker(s) in normal operation, without overload. The higher the rated power, the higher the sound volume, but louder devices and energy require more.

Among the functions in the table clock and radio you can find: alarm clock, snooze, voice notification, calendar, thermometer, world time, radio auto-off timer, time projection, dial backlight, case backlight, USB charging port, wireless charging gadgets, flashlight. More details about them:

- Alarm. The watch has a classic alarm clock that provides a sound signal at a customer-specified time. Of course, this function can be used not only for morning wake-up, but also for other warnings. However, the most popular way to use an alarm clock is to wake you up in the morning. In light of this, some models may provide a very specific way of disabling the alarm - for example, by installing a propeller in place that takes off from the clock when the alarm goes off; and some models begin to move at the same time as the signal, and you have to catch them. There can be many similar options, but they all follow the same principle: to push the customer to take active action and reduce the likelihood of falling asleep after the sound has been...turned off. Watches with original alarm clocks will be especially useful for tech who tend to wake up when they wake up, turning off the alarm and falling asleep again.

— Delay of the alarm signal (Snooze). As the name suggests, this function is designed to reschedule the alarm to a later time. Its meaning is that when a signal is triggered, the customer can literally move the alarm time by several minutes with just one click of a button. Snooze is intended primarily for tech who prefer to lie in bed for a while after the alarm goes off before getting up: it minimizes the risk of falling back to sleep and missing the time to wake up, while pressing the Snooze button is much easier than changing alarm clock manually. In some models, the delay time is fixed (usually about 5 - 10 minutes), in others it can be adjusted at will.

— Voice notification. The watch has a voice warning system. One of the most popular uses of such a system is to announce the current time at the press of a button; in some situations, this method of finding out the time can be more convenient than trying to look at the dial. Theoretically, other types of alerts could be provided - for example, a low battery warning; however, for a number of reasons they are rarely used.

- Calendar. The watch has a calendar function. This feature requires, at a minimum, the display of the current day of the month, but the matter is not limited to this: even in watches with pointer dials (see “Movement type”), the calendar can also cover the day of the week or even the current month, and in digital devices - also the year, the number of the week in the year and a lot of other information, including displaying calendar tables for each individual month. The calendar can also provide other functions, such as setting an alarm for certain days of the week.

- Thermometer. The presence of a thermometer function in the watch allows you to use it to determine the air temperature in the number. This function may be useful in cases where you need to maintain a certain microclimate - for example, if there is a baby in the house. Built-in thermometers, as a rule, are made electronic, which provides more than sufficient accuracy for domestic use. And in some models, the digital temperature display can be supplemented with a color one - for example, by changing the color of the housing backlight (see below for the backlight itself).

- World time. The presence of a world time function in the watch allows you to determine the current time in other regions. Most often, an additional dial is used for this, which is set in advance for the time of the time zone of interest and constantly displays this time; and in the most advanced models there may be several such dials. There are other ways to implement this function - for example, models with LCD screens (see “Dial type”) can provide quick switching between local time and a specified time zone. In any case, watches with a world time function are useful in cases where you regularly communicate with people from other time zones - in particular, they minimize the risk of being in an inconvenient situation by calling your interlocutor in the middle of the night or at another inopportune moment. On the other hand, today there are more practical ways to monitor standard time than desk clocks (for example, smartphones are equipped with similar tools); therefore, this function is rarely found, mainly in luxury models.

— Radio auto-off timer. A timer that turns off the receiver after a specified time. This way, you don't have to worry about turning off the device manually - just set the desired time and the receiver will turn off automatically. This can be useful, for example, if you like to fall asleep to music: by setting a timer, you can calmly fall asleep without worrying about wasting energy on “all-night” broadcasting (which is especially critical for self-powered devices, see “Power”).

— Time projection. The watch has a projector function. Thanks to it, the device is able to display various data not only on the dial, but also on various surfaces - for example, projecting information onto the ceiling or wall. In some cases, the projector mark is more convenient and better visible than the main dial. As the name of this feature suggests, the projector is primarily designed to display the time; technically, nothing prevents other data from being displayed in this way, however, for a number of reasons, such a possibility is rarely provided. As a rule, the projector unit is made rotating, which allows you to adjust it to different environments.

— Dial backlight. The watch has a dial illumination system. This backlight is convenient in low light conditions: it allows you to see the dial without using additional lighting sources (in other words, you can look at the watch even in complete darkness). Note that in this case we are talking about systems that turn on for a short time - usually for a few seconds while the customer holds the button; Constantly glowing symbols on the dial do not count as backlighting, although they can also be seen in the dark without any problems. And in some models, the dial illumination can be combined with the case illumination (see below).

— Case lighting. The watch has a case lighting system. Unlike the dial backlight described above, this function is usually not associated with the main functionality of the watch - it plays a decorative role and also allows the device to be used as a night light.

- Flashlight. The built-in flashlight allows you to use the receiver as a light source. Moreover, the power of such sources can be quite high, providing an effective range of several tens of meters. Usually this function involves a directional beam, but there are also diffused light flashlights.

— USB port for charging. The presence of a port for connecting a third-party gadget and replenishing its energy. Naturally, this solution is applicable when connecting a table clock to a 230 V power supply, and the speed itself will be mediocre.

- Wireless charger. Ability to work in Power Bank mode without using a cable. The gadget is charged wirelessly by placing the desired device on the charging area.

— Pencil stand. The presence of a pencil stand in the watch design. By design, such a stand usually represents a characteristic “glass”; its shape can be varied, but the dimensions are usually large enough to accommodate several fairly large stationery items. Therefore, despite the name, the stand can be used not only for pencils, but also for other items - pens, markers, scissors, etc.

Power supply methods provided in the design of radio receivers and table clocks.

- Batteries. Powered by standard replaceable batteries ( AA, AAA, type C, LR44, PP3, etc.). There are two main advantages to this diet. Firstly, a shrunken element can be quickly replaced; for this, of course, you need to have fresh batteries in stock, but it’s easy to take care of this in advance. Secondly, consumer devices are independent of outlets; this allows you to install them on almost any suitable surface, easily move from place to place, without worrying about the length and placement of the mains cable. Batteries, of course, need to be purchased separately, which slightly increases spending. However, many replacement batteries are also available as rechargeable batteries. Thanks to all this, battery-powered models are very popular today.

- Network. Powered by a standard 230 V network. On the one hand, this option eliminates the hassle of batteries, and on the other hand, connecting to the network is associated with a number of inconveniences: the power cord limits the ability to install a radio or clock in places where there are sockets nearby, moreover the device may interfere or simply not fit into the overall environment. Mai...ns power in watches is quite rare in its pure form - much more often it is used as a fallback option for battery-powered models: if the situation allows, you can plug the watch into an outlet and not waste the charge.

- Battery. Powered by an original battery that is not related to standard sizes. Like the batteries described above, this option provides the device with autonomy. However, the key difference is that the battery, as a rule, does not provide for quick replacement: a non-standard format makes it difficult to purchase a spare battery, and more often than not, it is generally made non-removable. Therefore, the main, if not the only, option for discharging is charging, which requires a connection to the network and takes quite a long time. As a result, rechargeable batteries are considered a less suitable power option than replacement batteries and are rarely used.

Theoretically, a higher capacity allows for greater autonomy, but in practice, operating time also depends on power consumption - and it can be very different, depending on the characteristics and design features.