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Ten-code. Ten-codes, officially known as ten signals, are brevity codes used to represent common phrases in voice communication, particularly by US public safety officials and in citizens band (CB) radio transmissions. The police version of ten-codes is officially known as the APCO Project 14 Aural Brevity Code. [1]
Radio frequency ( RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency [ 1] range from around 20 kHz to around 300 GHz. This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies, and also ...
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz ). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particularly in telecommunication. To prevent interference between different users, the generation and transmission of radio ...
The 2015 ITU World Radiocommunication Conference (WRC-15) approved a new worldwide frequency allocation of 5.351.5–5.366.5 MHz to the amateurs on a secondary basis. The allocation limits amateur stations to 15 watts effective isotropic radiated power (EIRP); however some locations will be permit up to 25 W EIRP.
In the United States, the Citizens Band Radio Service (CBRS), commonly called citizens band radio (CB radio), is one of several personal radio services defined under Title 47 of the Code of Federal Regulations, Part 95. [ 1] It is intended to be a two-way voice communication service for use in personal and business activities of the general ...
Cuban numbers station HM01. A recording of The Gong numbers station, run by the National People's Army of the German Democratic Republic, from 1988. A numbers station is a shortwave radio station characterized by broadcasts of formatted numbers, which are believed to be addressed to intelligence officers operating in foreign countries. [1]
These frequencies are known as the ISM bands (Industrial Scientific and Medical bands). The return signal of the tag may still cause interference for other radio users. [citation needed] Low-frequency (LF: 125–134.2 kHz and 140–148.5 kHz) (LowFID) tags and high-frequency (HF: 13.56 MHz) (HighFID) tags can be used globally without a license.
Radio waves are a type of electromagnetic radiation with the lowest frequencies and the longest wavelengths in the electromagnetic spectrum, typically with frequencies below 300 gigahertz (GHz) and wavelengths greater than 1 millimeter ( 3⁄64 inch), about the diameter of a grain of rice.