Walkie-Talkie Basics (1)
In outdoor activities, the role of walkie-talkies is greater than that of mobile phones in some cases. It does not require external base station support and can communicate freely with teammates in most harsh environments. Some also have three-proof and GPS functions. In times of catastrophe, walkie-talkies can not only send distress signals, but can also be used to listen to outside information. As a PSK, it is necessary to have some knowledge of walkie-talkies and reserve a pair of walkie-talkies for backup.
For friends who travel frequently, the walkie-talkie (hand station) must not be unfamiliar.
But what kind of handstand is suitable for friends like us who travel a lot?
What is a walkie-talkie:
The English name of the walkie-talkie is two-way radio. It is a two-way mobile communication tool. It can make calls without any network support. It is suitable for relatively fixed and frequent calls.
How to identify civilian walkie-talkies:
A: Anything with LCD screen, digital display tube, and digital buttons on the intercom is a civilian walkie-talkie. Its frequency range is between 100-500Mhz, which can be shielded by the new shield.
The frequency range of the walkie-talkie:
In the daily use of walkie-talkies, according to the regulations of the China Radio Regulatory Commission, the frequencies of walkie-talkies are generally divided as follows:
Professional walkie-talkie: V segment 136-174MHZ; U segment 400-470MHZ.
For armed police and public security: 350-390MHZ.
Coastal use: 220MHZ.
Traffic light monitoring, air defense siren: 223.025-235Mhz
Amateur use: 433MHZ.
For cluster: 800MHZ.
Mobile phone: 900MHZ/180MHZ.
Civil: 409-410MHZ.
According to electromagnetic theory, the lower the frequency and the longer the wavelength, the weaker the ability of the radio wave to penetrate the building, but the stronger the diffraction ability. The higher the frequency and the shorter the wavelength, the stronger the ability of the radio wave to penetrate the building, but the weaker the diffraction ability. Therefore, in the city, due to the high density of buildings, strong penetration of radio waves is required, so the higher the frequency, the more suitable; and the use of walkie-talkies in open areas such as the wilderness or the sea requires radio waves with strong diffraction ability, so the V(136-174MHZ) is more suitable.
