The walkie-talkie seems to be just a talking tool. In fact, to really be proficient in playing, you need to understand and learn some basic knowledge. In this way, you will deal with some special situations.
1 Maintenance Tips
1. After long-term use of the walkie-talkie, pressing the key, the control knob and the case will easily become dirty. Use neutral detergent (do not use strong corrosive chemicals) and a damp cloth to clean the case. The use of chemicals such as stain removers, alcohol, sprays, or petroleum preparations can cause damage to the walkie-talkie surface and casing.
2. Handle the walkie-talkie, do not move the walkie-talkie with the antenna.
3. When not using accessories such as headphones, please attach the dust cap (if equipped).
2 What is walkie talkie C?
C (Continuous Digital Controlled Squelch System) is a continuous digital control squelch system. Its function is the same as that of C, except that it uses digital coding as the condition for whether mute is turned on.
3 How to minimize harm of radiation when using walkie-talkie?
1. While the walkie-talkie is transmitting, keep the walkie-talkie in a vertical position and keep the microphone 2.5-5 cm from the mouth. When transmitting, the radio should be at least 2.5 cm from the head or body.
2. Do not perform multiple actions of turning on and off during use, and adjust the volume to a level suitable for your hearing.
4 How far is the talking distance?
The conventional communication distance can be up to 8-10 kilometers in the open area, and the general urban area can be 3-5 kilometers. In the case of tall buildings or high mountains, the communication distance will be relatively short. When there is network support, the call range can reach tens of kilometers. Networking uses a relay station (also called a base station or a relay station) to automatically receive the transmitted signals from it, and amplify and forward them. The network can have a large communication coverage and extend the communication distance. The open area can reach 10-20 kilometers (handheld) or even 30-50 kilometers (vehicle). The building can cover the basement, underground parking lot, fire passage, etc. For the dead end area.
5 How to deal with water ingress
1. The machine should be turned off immediately after entering the water, and the battery should be unplugged immediately;
2. Shake the water out vigorously and blow dry in a ventilated and dry place;
3. Transfer to the service center as soon as possible.
6 What is CTCS?
CTCS (Continuous Tone Controlled Squelch System), a continuous voice controlled noise suppression system, commonly known as sub-audio, is a technology that transmits frequencies below the audio frequency (67Hz-250.3Hz) to the audio signal. Because its frequency range is below standard audio, it is called sub-audio. After the radio performs IF demodulation on the received signal, the sub-audio signal is filtered, shaped, and input to the CPU, which is compared with the C frequency set by the unit to determine whether to turn on mute
7 Precautions for the use of walkie-talkie battery
1. Use original or approved batteries.
2. If metal conductors such as jewelry, keys, or beads touch the exposed electrodes of the battery, all batteries may cause damage or personal injury. Take care when a battery is fully charged, especially when you put it in a pocket, wallet, or other metal container.
3. Charging should be performed in an environment of 5-40 degrees. If this temperature range is exceeded, the battery life will be affected and the rated capacity may not be fully charged.
8 How to maintain the radio battery?
1. Do not short the terminals of the battery or throw the battery into a fire.
2. The battery can be charged when it is installed on the intercom, but the intercom needs to be turned off to ensure that the battery is fully charged.
3. The first three charges should be sufficient for 16 hours to reduce the memory function, and the subsequent charging time can be about 10 hours.
4. Do not leave the radio and battery on the charger when not charging. Continuous charging will shorten the battery life.
5. Whenever possible, the battery should be in an indoor environment of about 20 degrees Celsius. Charging when the temperature is below 10 degrees Celsius will cause the electrolyte to leak and eventually become a barrier battery.
6. For general nickel-hydrogen batteries and nickel-cadmium batteries. Before each charging, you must ensure that the battery of the radio is completely clean (that is, it cannot transmit normally when the radio PTT button is pressed). Otherwise, the radio battery will be remembered. This greatly reduces the battery life.
9 What is DTMF?
DTMF (Dual Tone Multi Frequency) is a dual-tone multi-frequency group consisting of a high-frequency group and a low-frequency group. Each of the high-frequency and low-frequency groups contains four frequencies. A high-frequency signal and a low-frequency signal are superimposed to form a combined signal, which represents a number. DTMF signaling has 16 codes. Use DTMF signaling to select the corresponding radio
10 What is intermodulation interference?
Two or more signals are tuned in a non-linear transmission circuit to produce a combined frequency close to the frequency of the useful signal, which causes interference to the radio intercom system, which is called intermodulation interference.
11 What is scanning (SCAN)?
In order to hear conversations on all channels, one of the listening methods used is scanning. By pressing the dedicated key, the receiving circuit is received one channel at a time in a certain order to listen to the signals in the channel. If the receiving time of each channel is 100ms, ten channels can be scanned per second, that is, the scanning speed is 10ch / s.
12 What is Battery Save Function
In order to save power and extend the standby time, the radio does not receive and press the key for a period of time. It will work by turning off the power and turning on the power for a period of time. This method is called power saving. The turn-on and turn-off time ratio is approximately 1: 4. When a signal is received or a key operation is performed, the radio immediately exits the power saving state and enters a normal state.
13 What are the reasons for the intercom?
There are three reasons for intermodulation: transmitter intermodulation, receiver intermodulation, and intermodulation caused by external effects. Intermodulation interference must meet three conditions at the same time:
⑴ Several interference frequencies and the nominal frequency of the interfered receiver have a certain spacing relationship;
⑵ the interference signal must have sufficient amplitude;
⑶ for receiver intermodulation, all Interfering and interfered receivers must operate simultaneously. Transmitter intermodulation means that two transmitters are coupled to each other to form interference. Receiver intermodulation means that when two or more strong interference signals enter the front-end circuit of the receiver due to their non-linear effects, the interference signals are mixed with each other to produce an intermodulation product that can fall into the receiver’s passband. Its size depends on factors such as the size of the interference signal. Intermodulation caused by external effects is caused by poor contact of the receiving plug-in fasteners such as transmitter high-frequency filters and antenna feeders or corrosion of metal components. Intermodulation occurs in a strong RF electric field to generate intermodulation and form interference radiation Caused by sources, such external effects intermodulation interference can be completely avoided.
14 What are channels and channel spacing?
Channel refers to the frequency value occupied by the transmission and reception. The frequency difference between adjacent channels is called the channel spacing. The specified channel intervals are 25KHz (broadband), 20KHz, 12.5KHz (narrowband), and so on.
15 What is co-channel interference?
Any wireless interference sent by other wireless signal sources with the same frequency as the local useful signal and entering the intermediate frequency passband of the receiver in the same way is called co-frequency interference. When both the interference signal and the useful signal enter the receiver, they are also amplified and detected. When the two signals have a difference in carrier frequency, they will be beat interference. When the modulation of the two signals is not large, it will cause distortion interference. Distortion will be caused when there is phase difference between two signals. The larger the interference signal, the stronger the received noise will be until it is impossible to answer. This phenomenon is mainly due to the mutual use of wireless communication equipment in the same frequency nearby too close to each other. It may be an illegal station or a legitimate station without assigned frequency for frequency reuse, but the distance is relatively close. Caused by.
16 What is the reference sensitivity?
Also known as the maximum available sensitivity, under the specified frequency and modulation, the input signal level of the standard signal-to-noise ratio (12dBSINAD) is generated at the receiving output.
17 What is adjacent channel power?
A transmitter operating in a channel-divided system has a portion of the total output power that falls within a specified bandwidth of any adjacent channel under specified modulation conditions.
18 What is adjacent frequency interference?
When the wireless signal is in the radio frequency passband of the receiver or near the passband, the interference caused by the frequency conversion and entering the intermediate frequency passband is called adjacent frequency interference. This interference can of course reduce the signal ratio of the receiver and reduce the sensitivity reading, but it is different from the same frequency interference. Adjacent frequency interference is mainly caused by the technical indicators of the wireless communication equipment itself not conforming to national technical standards.
19 What are the main factors affecting communication distance?
The main factors affecting the communication distance are the power of the radio station, the sensitivity of the radio station, the height of the antenna, the type of antenna, the length and diameter of the feeder, the spectral distribution of radio interference in the area, the relative position of tall buildings or metal objects and the antenna , Terrain and other environmental factors.
20 Radio use safety precautions
1. On cars with airbags, do not place the radio within the range that may be involved when the airbag is deployed. If the two-way radio is in the area that may be involved when the airbag is deployed, once the airbag is rapidly deployed, the two-way radio may injure people in the car with great impact.
2. In a potentially explosive atmospheric environment or occasion, unless the intercom is a specially certified explosion-proof intercom, the intercom must be turned off. In potentially explosive atmospheres, electric sparks can cause an explosion or fire.
3. Do not replace or recharge the battery in a potentially explosive atmosphere. Installing and removing the battery may cause contact with sparks and cause an explosion.
4. Before approaching the blasting area and the area, you must first turn off the two-way radio to avoid possible explosion.