A mode of listening used to receive weak signals. By pressing the special button to force on the receiving signal channel, the operator USES the ear to identify the weak sound in the loudspeaker to achieve the purpose of listening.
A listening method used to hear signals on all channels.
By pressing the scan special key, the receiving circuit receives channels one by one in a certain order for a period of time to receive the signals in the channel. If the receiving time of each channel is 100ms, ten channels can be scanned every second, that is, the scanning speed is 10ch/s.
Scan the priority channel during the scanning process.
Deletes or adds a channel from a scan list to a scan list.
When this function is activated, no need to press the PTT key,Can be directly through the voice launch operation.
This function is used to limit the user over time transmission on a channel, and also to avoid radio damage caused by long time transmission.
Save electricity and extend the standby time.
During a period of time, No transmit receiving and keystroke operation. Radio will work in a way that shuts down for a while and turns it on for a while,This way is called energy saving. The switching time length ratio is about 1:4. When the signal is received or the key is pressed, the radio immediately exits the power-saving state and enters the normal state.
This function allows users to choose high or low power according to the actual situation.
When use this function, the user is forbidden to transmit signals on busy channels.
During receiving signals, the intensity of the noise corresponds to the intensity of the signal, and the stronger the signal, the weaker the noise. The maximum noise and the minimum noise are divided into several levels, each level is called a Squelch level.
Use this feature to avoid receiving irrelevant calls.
Call the appropriate radio using 2-tone or DTMF signaling options.
When using reverse frequency function, the transmitting and receiving frequencies of the radio will be exchanged. and the set signaling is also exchanged.
When using Talk Around function, The radio transmit frequency will be same as the receiving frequency.
When the intercom receives a properly coded call, it sends a signal to the caller in response to the call.
Press the special alarm key, the radio will send the maximum sound or the predetermined alarm code to other handheld devices or base stations.
Use this feature to prevent key misoperations.
Display radio battery level.
For radio operation at night or in dim conditions, you can see the radio LCD display and buttons.
To control the variation of the carrier parameters by one or more of the parameters of the modulating signal,
According to the different control parameters, modulation can be divided into amplitude modulation, frequency modulation and phase modulation.
Audio refers to the sound frequency of a person speaking. Usually refers to the frequency band of 300Hz-3400Hz.
Voice, digital signals, signaling and other useful signal carrier, easy to transmit high-frequency electromagnetic waves.
Channel refers to the frequency value occupied by transmitting and receiving. The difference in frequency between adjacent channels is called channel spacing. The required channel spacing is 25KHz(broadband), 20KHz, and 12.5KHz(narrowband).
2-tone signaling consisting of two audio signals, A Tone + B Tone.
First send A Tone for a period of time, and then send B Tone after A period of time. The 2-tone signaling can be used to select the corresponding radio.
5-Tone is the same as the two-tone, but it is composed of five frequencies.
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