|
409 MHz
Public Radio Service (PRS) is a walkie-talkie personal radio service in the People's Republic of China, including Hong Kong and Macau, but excluding Taiwan. It can be used without a license. It uses 409 MHz. It is also known as PRS409.423 号文件） (trans-title:Technical requirements for micropower (short range) radio transmitting equipment) page 8 ] It is similar to the American Family Radio Service (FRS) and PMR446 in the European Union. Technical information The PRS radios use narrow-band frequency modulation (NBFM) with a maximum deviation of 2.5 kHz. The channels are spaced at 12.5 kHz intervals. They are limited to 500 milliwatts effective radiated power. See also * 70-centimeter band * CDCSS * Continuous Tone-Coded Squelch System (CTCSS) * General Mobile Radio Service * KDR 444 * LPD433 * Multi-Use Radio Service In the United States, the Multi-Use Radio Service (MURS) is a licensed by rule (i.e. under part 95, subpart J, of title 47, Code of Federal Regulation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDCSS
In telecommunications, squelch is a circuit function that acts to suppress the audio (or video) output of a receiver in the absence of a strong input signal. Essentially, squelch is a specialized type of noise gate designed to suppress weak signals. Squelch is used in two-way radios and VHF/UHF radio scanners to eliminate the sound of noise when the radio is not receiving a desired transmission. Carrier squelch A carrier squelch or noise squelch is the most simple variant of all. It operates strictly on the signal strength, such as when a television mutes the audio or blanks the video on "empty" channels, or when a walkie-talkie mutes the audio when no signal is present. In some designs, the squelch threshold is preset. For example, television squelch settings are usually preset. Receivers in base stations, or repeaters at remote mountain top sites, are usually not adjustable remotely from the control point. In two-way radios (also known as radiotelephones), the received s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Hobbies
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is very widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraft and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UHF CB
UHF CB is a class-licensed citizen's band radio service authorised by the governments of Australia, New Zealand, Vanuatu, and Malaysia in the UHF 477 MHz band. UHF CB provides 77 channels, including 32 channels (16 output, 16 input) allocated to repeater stations. It is similar in concept to the General Mobile Radio Service in the United States. Equipment User equipment designs are similar to commercial land mobile two-way radio, except the maximum legal output power is 5 Watts. External antennas are permitted and commercially manufactured antennas have gains as high as 12 dB. Handheld transceivers (handy talkies) are permitted and have transmit power from 500 mW to 5 W (full legal power) and are relatively cheap compared to full-sized transceivers. Operation in the band is restricted to modes F3E and G3E ( FM or PM of analogue voice telephony) except for channels 22 and 23, which are data modes only. Licensing Class licensing means that users do not have to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Radio Service
A personal radio service is any system that allows individual to operate radio transmitters and receivers for personal purposes with minimal or no special license or individual authorization. Personal radio services exist around the world and typically use light-weight walkie talkie portable radios. The power output, antenna size, and technical characteristics of the equipment are set by regulations in each country. Many regions (for example, the European Union) have standardized personal radio service rules to allow travelers from one country to use their equipment in another country. Examples of standardized services include PMR446 and FM Citizens Band Radio (CB) in the EU and several other countries/regions. 26–27 MHz CB radio is the oldest personal radio service and is used in nearly every country worldwide, with many countries and regions copying the United States 40-channel frequency plan. In many countries, CB radio is less popular due to the availability of other pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-Use Radio Service
In the United States, the Multi-Use Radio Service (MURS) is a licensed by rule (i.e. under part 95, subpart J, of title 47, Code of Federal Regulations) two-way radio service similar to the Citizens band (CB). Established by the U.S. Federal Communications Commission in the fall of 2000, MURS created a radio service allowing for licensed by rule (Part 95) operation in a narrow selection of the VHF band, with a power limit of 2 watts. The FCC formally defines MURS as "a private, two-way, short-distance voice or data communications service for personal or business activities of the general public." MURS stations may not be connected to the public telephone network, may not be used for store and forward operations, and radio repeaters are not permitted. In 2009, Industry Canada (IC) established a five-year transition plan, which would have permitted the use of MURS in Canada starting June 2014. In August 2014 IC announced a deferral of MURS introduction, as "the Department does not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LPD433
LPD433 (low power device 433 MHz) is a UHF band in which license free communication devices are allowed to operate in some regions. The frequencies correspond with the ITU region 1 ISM band of 433.050 MHz to 434.790 MHz, and operation is limited to CEPT countries. The frequencies used are within the 70-centimeter band, which is currently reserved for government and amateur radio operations in the United States and most nations worldwide. LPD hand-held radios are authorized for licence-free voice communications use in most of Europe using analog frequency modulation (FM) as part of short range device regulations, CEPT/ERCbr> REC 70-03 (22 August 2011) with 25 kHz channel spacing, for a total of 69 channels. In some countries, LPD devices may only be used with an integral and non-removable antenna with a maximum legal power output of 10 mW. Voice communication in the LPD band was introduced to reduce the burden on the eight (now sixteen) PMR446 channels over shorter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KDR 444
KDR 444 (Norwegian "kortdistanseradio", Swedish "kortdistansradio", "short distance radio") or KDR, is a licence-free personal radio service in the UHF range used in Sweden and Norway. It is usually referred to as SRBR 444 (Short Range Business Radio) in Sweden. Transmitters are limited to 2 W ERP (previously 1 W) in Sweden and 0.5 W in Norwayhttp://www.lovdata.no/cgi-wift/ldles?ltdoc=/for/ff-20120119-0077.html#40 Norwegian regulation on general permission for use of frequencies $40 (2) n Norwegian/ref>. FM with a bandwidth of 25 kilohertz is used. Norway require a radio with fixed antenna to be used with these frequencies. Channels Norway has 6 channels, while Sweden has 8 channels. Note that channel 6 is different in Norway and Sweden. Channels use FM. Frequencies 444.875 and 444.925 are newer frequencies available in Sweden but may not be available in some other regions (such as Norway); older equipment may also lack these new frequencies. Consequently, 444.975 is likely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Mobile Radio Service
The General Mobile Radio Service (GMRS) is a land-mobile FM UHF radio service designed for short-distance two-way communication and authorized under part 95 of 47 USC. It requires a license in the United States, but some GMRS compatible equipment can be used license-free in Canada. The US GMRS license is issued for a period of 10 years by the FCC. The United States permits use by adult individuals who possess a valid GMRS license, as well as their immediate family members.The FCC definition of “immediate family” includes the licensee’s spouse, children, stepchildren, parents, stepparents, siblings, grandparents, aunts, uncles, nephews, nieces, and in-laws. See . Immediate relatives of the GMRS system licensee are entitled to communicate among themselves for personal or business purposes, but employees of the licensee who are not family members are not covered by the license. Non-family members must be licensed separately. GMRS radios are typically handheld portable d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous Tone-Coded Squelch System
In telecommunications, Continuous Tone-Coded Squelch System or CTCSS is one type of in-band signaling that is used to reduce the annoyance of listening to other users on a shared two-way radio communication channel. (See squelch.) It is sometimes referred to as tone squelch. It does this by adding a low frequency audio tone to the voice. Where more than one group of users is on the same radio frequency (called ''co-channel users''), CTCSS circuitry mutes those users who are using a different CTCSS tone or no CTCSS. It is sometimes referred to as a sub-channel, but this is a misnomer because no additional channels are created. All users with different CTCSS tones on the same channel are still transmitting on the identical radio frequency, and their transmissions interfere with each other; however; the interference is masked under most conditions. The CTCSS feature also does not offer any security. A receiver with just a carrier or noise squelch does not suppress any sufficiently s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
70-centimeter Band
The 70-centimeter or 440 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio and amateur satellite use. The ITU amateur radio allocation is from 430 to 440 MHz; however, some countries, such as the United States, allocate hams 420 to 450 MHz. Depending on the country the band is shared with other radio services (in United States with government radar systems such as PAVE PAWS). 70 centimeters is a popular ham band due to the ready availability of equipment in both new and used markets. Most amateurs operating on 70 cm use either equipment purpose-built for ham radio, or commercial equipment designed for nearby land mobile frequencies. Amateurs predominately use the band for FM or digital voice communications through repeaters (useful for emergency communications), as well narrow band modes (analog and digital) for long-distance communications (called "DX", including Moonbounce). The band is also popular for Amateur Satellite Ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
