Intercom has frequency limitation
2018/06/20 | by:

 In order to ensure that the vast majority of users do not interfere with calls and make reasonable use of frequency resources, the National Radio Station Management Committee has divided the use of frequencies and specified that different industries use the corresponding frequency range. When users purchase a walkie-talkie, they must apply to the local Radio Management Committee for frequency points.

The public walkie-talkie refers to a wireless walkie-talkie whose transmit power is not more than 0.5W and works at a specified frequency. Radio frequency technical indicators such as radio transmission frequency and power must meet the following requirements:

1. Operating frequency (.9000; 409. Unit: MHz): 409.7500, 409.7625, 409.7750, 409.7875, 409.8000, 409.8125, 409.8250, 409.8375, 409.8500, 409.8625, 409.8750, 409.8875, 4099125, 409.9250, 409.9375, 409.9500, 409.9625, 409.9750 , 409.9875;

2, modulation method: F3E;

3, effective transmit power (EIRP): < 0.5W;

4, transmission frequency tolerance: <+5ppm;

5, transmitter spurious radiation: <50uW;

6, receiver spurious radiation: <20nW;

7, channel spacing: 12.50kHz

power control

When the CPU is in different states, different power sources are sent out

Receive power: normal intermittent operation to ensure power saving

Emission power: only when transmitting

CPU power: stable power