TYT Handheld Radio Microphone Speaker MIC For Tyt Two Way

Walkie talkie, without any network support, you can talk, no phone charges, is suitable for relatively fixed and frequent talk occasions, consisting of shell, host, battery, belt clip, charger, antenna. Walkie-talkies have three categories: analog walkie-talkies, digital walkie-talkies, IP walkie-talkies.
Chinese name Walkie-Talkie Foreign name Walkie-Talkie [12-13] type mobile communication tool features two-way birth place Westinghouse laboratory inventor John Kermode field mobile communication advantages convenient, fast
The development history
Walkie talkie is the terminal equipment of cluster communication. It can not only be used as the terminal equipment of cluster communication, but also as a professional wireless communication tool in mobile communication. [1]
The intercom covers a wide range. Here we will work in the ultra-short wave frequency band (VHF 30 ~ 300 MHz, UHF 300 ~ 3000 MHz) radio communication equipment are collectively called radio walkie-talkie, in fact according to the relevant national standards should be called ultra-short wave FM radio telephone. People usually small power, small volume of the handheld wireless telephone is called "walkie-talkie", before someone called it "chat machine", "walkie-talkie"; And the large power, large volume can be installed in vehicles (ships) and other vehicles or fixed use of radio telephone called "radio", such as vehicle-mounted station (vehicle-mounted machine), Marine station, fixed station, base station, turntable, etc. [1]
Radio walkie-talkie is the first wireless mobile communication equipment used by human beings, as early as in the 1930s began to be applied. In 1936, MOTOROLA developed the first mobile radio communication product -- "patrol card" AM vehicle radio receiver. Later, in 1940, it developed the first 2.2-kg hand-held two-way radio AM walkie-talkie for the US Signal Corps, with a communication range of 1.6 km. In 1962, MOTOROLA introduced the HT200, the first hand-held walkie-talkie weighing only 935G. Its shape was called "brick", and it was about the same size as early mobile phones. [1]
Intercom appearance collection
Walkie-talkie Appearance Collection (17 pieces)
After nearly a century of development, the application of walkie-talkies has been very common, has been from the specialized field to the general consumption, from the military to civilian expansion. It is not only a professional wireless communication tool in mobile communication, but also a consumption tool with the characteristics of consumer products that can meet People's Daily needs. A walkie-talkie is a terminal device for point-to-point communication. It enables many people to communicate with each other at the same time, but only one person can speak at a time. Compared with other communication methods, this communication method has the characteristics of instant communication, instant response, economical and practical, low operating cost, no call cost, easy to use, and has the functions of group call, system call, confidential call and so on. In dealing with emergency or dispatching command, its role is other communication tools can not be replaced. Most of the traditional walkie-talkies use simplex analog communication mode, and some walkie-talkies use frequency division duplex analog communication mode. Digital walkie-talkies are used more in cluster communication, but most of them are frequency division duplex. Walkie-talkies and other wireless communication tools, such as mobile phones, have different market positioning and are difficult to replace each other. The walkie-talkie is by no means an obsolete product; it is here to stay. With the development of economy and social progress, people pay more attention to their own safety, work efficiency and quality of life, the demand for radio walkie-talkies will also grow. The public's extensive use of walkie-talkies has promoted the walkie-talkies to become a popular and dependent communication tool. [1]
The characteristics of
1. Walkie-talkies are not restricted by the network, and they allow users to communicate easily in places not covered by the network. [1]
2. Walkie-talkie provides one-to-one, one-to-many call mode, press to say, easy operation, make communication more free, especially in emergency dispatch and collective work, these characteristics are very important. [1]
3. Low call cost. [1]
The working principle of
The working principle of the intercom is as follows: [1]
1. Launch part: [1]
PLL and VCO (voltage controlled oscillator) generate the transmitted RF carrier signal, after buffer amplification, excitation amplification, power amplifier, generating rated RF power, through the antenna low-pass filter, suppress harmonic components, and then transmitted out through the antenna. [1]
2. Receiving part: [1]
The receiving part mixes the amplified signal from the RF with the first oscillator signal from the PLL frequency synthesizer circuit at the first mixer and generates the first IF signal. The first IF signal is passed through the crystal filter to further eliminate the clutter signal in the adjacent channel. The filtered first IF signal enters the IF processing chip, and is mixed with the second local oscillator signal again to generate the second IF signal. The second IF signal passes through a ceramic filter to filter out the useless stray signal, and is amplified and discriminated to generate the audio signal. Audio signals through amplification, bandpass filter, de-weighting circuit, into the volume control circuit and power amplifier amplification, drive speakers, get the information people need. [1]
3. Modulation signal and modulation circuit: [1]
An electrical signal in which human speech is converted into audio by a microphone [1]
4. Signaling processing: [1]
CTCSS/CDCSS signals generated by CPU are amplified and adjusted, and then modulated into VCO. After receiving the low frequency signal, part of the signal is filtered and shaped by the amplified and sub-audio bandpass filter, and enters the CPU, compares with the preset value, and controls the output of the audio power amplifier and loudspeaker. That is, if the value is the same as the preset value, the speaker is turned on; if the value is different, the speaker is turned off.