The small walkie-talkie may seem simple, but in fact it has hidden mysteries, and it is exquisite everywhere. Today I will share with you these "advanced" usage tips, do you know?
01-How to set up Yayin
Assuming that you accidentally set up a channel like a stranger, how to prevent others from hearing your own messages, then you need to add a password to this channel.
(1) Digital encryption
Add some specific digital codes (usually a three-digit octal digital signal, represented by DCS) to the normally transmitted signal. This method is called digital encryption, and the basic principle is the same as that of analog encryption. As far as communication quality is concerned, the two are the same, because they are only used as an identification signal and will be removed once the identification is completed. The difference between the two lies in the fact that analog encryption is generally processed by analog circuits, while digital encryption needs to be processed by digital circuits. Relatively speaking, digital circuits are more accurate, easier to process, and programmable than analog circuits. The setting method is basically similar to that of analog mute audio.
(2) Simulated encryption:
Add another audio signal that cannot be heard by human ears to the normally transmitted signal. This audio signal is called a mute or sub-audio signal, and the frequency of the mute audio signal set by the sender and receiver should be the same. When the sender attaches a mute audio signal, the receiver can only turn on the pre-squelch circuit after receiving the same mute audio, let the signal be transmitted to the subsequent circuit, demodulate the normal audio signal, and the user can hear the normal audio ; Otherwise, if the receiver does not set the mute audio function or does not match the mute audio frequency of the sender, the squelch circuit cannot be turned on, and of course the normal audio signal cannot be heard. Setting method: set the communication frequency first; then call up the mute audio setting operation by pressing "function key + number key"; then adjust the mute audio value as needed; store it in the channel.
02-How to set different frequencies for receiving/transmitting
Receiving and transmitting can be at the same frequency or at different frequencies. In general, the communication quality of receiving/transmitting different frequencies is higher than that of receiving/transmitting the same frequency.
Setting method: First, switch the operating mode of the walkie-talkie to frequency mode, first input the receiving frequency value; then use the "function key + number key" to call up the setting function of receiving/transmitting different frequencies, generally there are two or three options: +, -, same frequency. The so-called "+" means that the transmitting frequency is higher than the receiving frequency based on the current receiving frequency; the so-called "-" means that the transmitting frequency is lower than the receiving frequency. Select "+" according to whether the transmitting frequency is higher or lower than the receiving frequency. "Or "-"; then use the "function key + number key" to call the difference frequency value setting function, set this value to the desired difference between the receiving and transmitting frequencies (for example, the receiving frequency is 145.35, the transmitting frequency is 144.35 , The transmitting frequency is 1M lower than the receiving frequency, it should be set to "-", and the difference frequency value is set to 1M), and then store the above data according to the channel storage method, that is, the different frequency of receiving/transmitting is realized.
Some machines are specially set up with two storage keys to store the receiving frequency and transmitting frequency respectively. At this time, first switch to the frequency mode, input the receiving frequency and store it with the receiving storage key, and then input the transmitting frequency and store it with the transmitting storage key.
03-How to set the squelch level
All walkie-talkies are equipped with a so-called "squelch circuit" in the front stage, whose function is to remove and prevent the relatively low level of interference noise signals from entering the back stage circuit, and only allow the effective signal transmission with a higher level Go to the subsequent circuit and demodulate the audio signal.
Through this circuit, the received noise level value can be set, which is generally called the squelch level value. This value is usually represented by the level, which is generally 0-9 level. Level 0 is the lowest, which means that the noise level value is set to the minimum In fact, there is no noise signal threshold set, allowing any level of noise signal (including effective signal) to pass. At this time, there will always be noise signals in the walkie-talkie, and normal audio signals will definitely not be heard; level 9 is the highest. Means that the noise level value is set to the highest value, and only signals above this level value can pass, and signals below this value cannot pass.
The squelch level value depends on the environment in which the walkie-talkie is used, and it is not better to be larger or smaller; if there is not much noise in the environment, set the squelch value to be low, which will help improve the receiver sensitivity of the walkie-talkie; if you use environmental noise If larger, the squelch value needs to be set high.
04-How to set up dual watch and priority channel scanning
In some special cases, you may need to watch several frequencies at the same time when using the walkie-talkie. In this case, the dual watch function plays a great role.
In addition, there is another situation: in general, listening to a certain frequency, but there is another frequency that needs to be watched and processed first. In this case, you need to use the priority channel scanning function of the walkie-talkie. Many walkie-talkies (including fixed-channel walkie-talkies) have a priority channel scanning function.
Theoretically speaking, the walkie-talkie can only receive or transmit one frequency signal at each instant, so absolute "dual waiting" is impossible. It is only time-sharing to process two different frequencies. This time interval is generally a few Seconds (5~7 seconds), that is, when listening to a certain frequency, scan another frequency every few seconds. When a call is heard on another frequency, it will temporarily stay on this frequency and then use this frequency. After the communication is completed, it returns to the first frequency of the watch.
The dual-wait and priority channel scanning function can operate in frequency mode or channel mode, but it is best to operate in channel mode.
Dual standby: first store the two frequencies to be watched in the two channels, and then enable the dual standby function of the two channels through "function key + number key", after that, the walkie-talkie will alternately scan on the two channel frequencies.
Priority channel scanning: first store the frequency and various parameters that need to be scanned first in the "priority channel" (Pr) specially set by the walkie-talkie; then enable the priority channel scanning function through the function key; then, wait on another frequency .
Of course, not all walkie-talkies have dual-waiting functions. When choosing walkie-talkies, you can determine the functional value requirements of the walkie-talkies you buy according to your own usage.
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