Detailed explanation of the internal structure and performance parameters of the walkie-talkie

What are the main components of the walkie-talkie host?

1. Shell: Professional machine generally uses PC+ABS, which has very good performance. It has good appearance, good aging and wear, and the product is sturdy and durable. Commercial machines often use engineering plastic ABS in appearance, strength, wear resistance and aging. All aspects can meet the requirements very well; the buttons are made of silica gel, which is resistant to abrasion, aging, and feels good; the aluminum shell is made of lightweight material aluminum alloy ADC12, which is easy to form and follow-up.

2, the host: generally includes the face shell, PTT button, earphone and power jack plug, PCB components, LCD part, volume / switch button, coding knob, indicator light, MIC and so on. The PTT button acts as a launch switch, typically on the side. The indicator light indicates the working status, usually at the top. There is also a volume/switch button and a coding knob (select channel) on the top of the radio. The LCD part visually displays the working status of the intercom. The PCB component is the core part of the walkie-talkie. The important components are on the PCB, and non-professionals are not allowed to disassemble. Most walkie-talkies require special shields, aluminum shells (fixed PCBs), etc. due to technical performance and drop resistance requirements. Professional machines also have waterproof requirements and the structure is more complicated.

3, battery: battery is divided into Ni-Cd, Ni-MH battery and Li-ion battery, the capacity is 600mAh, 800 mAh, 1100 mAh, 1500 mAh. Lithium batteries are expensive and still in the development stage. Ni-Cd and Ni-MH batteries are commonly used, and Ni-MH batteries are generally recommended for large-capacity batteries. The battery surface and the bottom case are ultrasonically welded and are firm and reliable.

4, belt clip: the role is to fix the walkie-talkie on the belt, for the convenience of the customer, the belt clip can be removed.

5. Antenna: It is divided into two parts: the antenna jacket and the antenna core. The antenna jacket is made of high-performance TPU material, which is resistant to bending and aging. The antenna core is generally connected to the main body by a threaded structure, which is easy to disassemble.

6, seat charge: share with the fire cattle to charge the battery or the whole machine. The structure generally has a DC socket, a charging shrapnel, an indicator light, a button, and the like. The DC socket is connected to the AC adapter, and the shrapnel is connected to the battery pole piece. The indicator light indicates the charging state, and the button acts as a discharge. The charger can generally charge the battery and the whole machine.

7. In addition, the walkie-talkie also has accessories such as leather cases and earphones for customers to choose.

What are the main performance indicators of the walkie-talkie?

The walkie-talkie has the following main performance indicators:

1. Frequency error: the difference between the unmodulated carrier frequency and the assigned frequency.

2. Output carrier power: The average power of the transmitting rack to the transmission line in one RF cycle without modulation.

3. Spurious radio frequency component: A signal having a significant component on a discrete frequency or in a narrow frequency band, in addition to the modulation component at the vicinity of the carrier and its transmission bandwidth. Includes harmonic and non-harmonic and parasitic components.

4. Adjacent channel power: The portion of the total output power that falls within the specified bandwidth of any adjacent channel under the specified modulation conditions for the transmitter operating in a channel-divided system.

5. Audio distortion: the ratio of the rms value of the uncorrupted chord signal of its fundamental component to the rms value of the full signal, expressed as a percentage. This distorted sinusoidal signal includes harmonic components, power supply ripple, and anharmonic Wave component. 6. Modulation Limit: The transmitter audio circuit prevents the modulation from exceeding the maximum allowable offset.

7. Rated audio output power: The power that can be obtained when the receiver is connected to the specified load under the specified working conditions.

8. Reference sensitivity: Also known as the maximum available sensitivity, the input signal produces a standard signal-to-noise ratio (12dBSINAD) input signal level at the specified frequency and modulation.

9. Selectivity: Characterizes the receiver's ability to resist input signals with input signals. It is evaluated by measuring the performance of adjacent signal selectivity, co-channel rejection, blocking, spurious response, and intermodulation immunity.

It should be pointed out that the electrical performance indicators of walkie-talkies are different standards in different countries and regions and different industries. Because the measurement methods of each standard are also different, it is not possible to judge the level of product indicators simply according to the value of the indicators. There are specific standards based. For example, the intermodulation immunity index, the European standard, the US FCC, and the Hong Kong Telecommunications Authority standards, due to the different measurement methods, the index values ​​are very different when measuring the same machine.