Radio training materials

Radio training materials

Radio allocation

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use:
Ultra-long wave is mainly used for submarine communication, long-distance communication, etc. Long wave is mainly used for transoceanic communication, medium distance communication, underground rock communication. Medium wave is mainly used for marine communication. , 3 ～ 9MHz at night
The meter wave is mainly used for ionospheric scattering communication (30 ～ 60MHz), meteor trail communication (30 ～ 100MHz), the equal decimeter wave is mainly used for microwave relay communication (352 ～ 420MHz / 1.7 ～ 2.4GHz), tropospheric scattering communication ( 700M ～ 10GHz) and navigation satellite communications (1.5G ～ 1.6GHz)
The centimeter wave is mainly used for microwave relay communication (3.6 ～ 4.2GHz / 5.85 ～ 8.5GHz), digital communication and satellite communication. The millimeter wave is mainly used for communication and waveguide communication when the spacecraft re-enters the atmosphere

The international code for transmission characteristics in mobile radio communications (1979):

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ITU's regulations on some bandwidth in communication:
Voice frequency: 350 ～ 2700Hz
AM radiotelephone: about 5400Hz bandwidth wideband frequency modulation WBFM: maximum frequency deviation 12 ～ 15kHz, channel spacing 40kHz
Narrowband FM NBFM: maximum frequency deviation 5kHz, channel spacing 20kHz and 25kHz
Ultra-narrowband FM SBFM: maximum frequency deviation ± 2.5kHz

Ten-band radio frequency band allocation:
FM: 88 ～ 108MHz
MW: 535 ～ 1605KHz
LW: 150 ～ 270KHz
SW1: 4.75 ～ 5.10MHz
SW2: 5.85 ～ 6.20MHz
SW3: 7.10 ～ 7.50MHz
SW4: 9.45 ～ 9.90MHz
SW5: 11.50 ~ 11.95MHz
SW6: 15.10 ～ 15.55MHz
SW7: 17.55 ～ 18.00MHz

FM FM radio gain distribution:

Frequency spectrum of pilot stereo broadcast transmitter:

TV gain distribution:

PAL-D image intermediate frequency characteristics:

TV stereo and multi-accompaniment (FM-FM system):

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