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4 Metres
The 4-metre (70 MHz) band is an amateur radio band within the lower part of the very high frequency (VHF) band. As only a few countries within and outside of Europe have allocated the band for amateur radio access, the availability of dedicated commercially manufactured equipment is limited. Most radio amateurs active on the band are interested in home construction or the modification of private mobile radio (PMR) equipment. As a result, communication on the 4-metre band tends to focus on technical topics, with long Contact (amateur radio), 'rag chews' being the norm as long as there is some local activity. History Before World War II, British community radio stations had been allocated a band at 56 MHz. After the war ended, they were moved to the 5-metre band (58.5–60 MHz) instead. This only lasted until 1949, as the 5-metre band was earmarked for BBC Television broadcasts. Meanwhile, in 1948, 72-72.8 MHz was allocated to France (until 1961). In 195 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Radio Band
Amateur radio frequency allocation is done by national telecommunication authorities. Globally, the International Telecommunication Union (ITU) oversees how much radio spectrum is set aside for amateur radio transmissions. Individual amateur stations are free to use any frequency within authorized frequency ranges; authorized bands may vary by the class of the station license. Radio amateurs use a variety of transmission modes, including Morse code, radioteletype, data, and voice. Specific frequency allocations vary from country to country and between ITU regions as specified in the current ITU HF frequency allocations for amateur radio. The list of frequency ranges is called a ''band allocation'', which may be set by international agreements, and national regulations. The modes and types of allocations within each frequency band is called a bandplan; it may be determined by regulation, but most typically is set by agreements between amateur radio operators. National authoriti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandwidth (signal Processing)
Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies. It is typically measured in hertz, and depending on context, may specifically refer to ''passband bandwidth'' or ''baseband bandwidth''. Passband bandwidth is the difference between the upper and lower cutoff frequencies of, for example, a band-pass filter, a communication channel, or a signal spectrum. Baseband bandwidth applies to a low-pass filter or baseband signal; the bandwidth is equal to its upper cutoff frequency. Bandwidth in hertz is a central concept in many fields, including electronics, information theory, digital communications, radio communications, signal processing, and spectroscopy and is one of the determinants of the capacity of a given communication channel. A key characteristic of bandwidth is that any band of a given width can carry the same amount of information, regardless of where that band is located in the frequency spectrum. For example, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dublin
Dublin (; , or ) is the capital and largest city of Republic of Ireland, Ireland. On a bay at the mouth of the River Liffey, it is in the Provinces of Ireland, province of Leinster, bordered on the south by the Dublin Mountains, a part of the Wicklow Mountains range. At the 2016 census of Ireland, 2016 census it had a population of 1,173,179, while the preliminary results of the 2022 census of Ireland, 2022 census recorded that County Dublin as a whole had a population of 1,450,701, and that the population of the Greater Dublin Area was over 2 million, or roughly 40% of the Republic of Ireland's total population. A settlement was established in the area by the Gaels during or before the 7th century, followed by the Vikings. As the Kings of Dublin, Kingdom of Dublin grew, it became Ireland's principal settlement by the 12th century Anglo-Norman invasion of Ireland. The city expanded rapidly from the 17th century and was briefly the second largest in the British Empire and sixt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplitude Modulation
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the amplitude (signal strength) of the wave is varied in proportion to that of the message signal, such as an audio signal. This technique contrasts with angle modulation, in which either the frequency of the carrier wave is varied, as in frequency modulation, or its phase, as in phase modulation. AM was the earliest modulation method used for transmitting audio in radio broadcasting. It was developed during the first quarter of the 20th century beginning with Roberto Landell de Moura and Reginald Fessenden's radiotelephone experiments in 1900. This original form of AM is sometimes called double-sideband amplitude modulation (DSBAM), because the standard method produces sidebands on either side of the carrier frequency. Single-sideband modulation uses bandpass filters to eliminate one of the sidebands and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRLP
The Internet Radio Linking Project, also called IRLP links amateur radio stations around the world by using Voice over IP (VoIP). Each gateway consists of a dedicated computer running custom software that is connected to both a radio and the Internet. This arrangement forms what is known as an IRLP Node. Since all end users communicate using a radio as opposed to using a computer directly, IRLP has adopted the motto ''"Keeping the Radio in Amateur Radio"''. Amateur radio (or ''ham'') operators within radio range of a local node are able to use DTMF tone generators to initiate a node-to-node connection with any other available node in the world. Each node has a unique 4 digit node number in the range of 1000–8999. A real-time searchable list of all nodes worldwide (including their current status) is available anytime by viewing the IRLP Network at a Glance. As of February 2019, there are over 1,500 active nodes. IRLP connections are of two types: node to node, and node to reflec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software-defined Radio
Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in analog hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which were once only theoretically possible. A basic SDR system may consist of a personal computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the general-purpose processor, rather than being done in special-purpose hardware (electronic circuits). Such a design produces a radio which can receive and transmit widely different radio protocols (sometimes referred to as waveforms) based solely on the software used. Software radios have signif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Amateur Radio Transceivers
This is a list of amateur radio transceivers. Alinco Land * DJ-100 * DJ-A10/A40 * DJ-A11/A41 * DJ-A35 * DJ-A36 * DJ-A446 * DJ-CRX series * DJ-VX10/50 * DJ-VX11 series * DJ-W10 * DJ-W18 * DJ-W35 * DJ-W58 * DJ-W100 * DR-138/438 * DR-CS10 Baofeng RX and TX below and elsewhere are ham radio jargon for receive and transmit. UV-5R The Baofeng UV-5R is a hand-held radio that has been marketed illegally in the United States and was produced since 2012. It has been used in a number of projects involving radios. It is described as a popular inexpensive model. Features The UV-5R is designed to transmit on the 2 meter band between 136 and 174 MHz and on the 70 cm band between 400 and 520 MHz. Features include CTCSS and duplex operation for use with local repeaters, dual watch and dual reception, an LED flashlight, voice prompts in either English or Chinese and programmable LED lighting for the LCD display. Illegal marketing and distribution in the Unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transverter
In radio engineering, a transverter is a radio frequency device that consists of an upconverter and a downconverter in one unit. Transverters are used in conjunction with transceivers to change the range of frequencies over which the transceiver can communicate. In electrical power engineering, a transverter is a universal electrical power converter that can combine, convert, analyze and control any combinations of DC or AC power. Amateur radio use Although not as convenient as a wide-range radio, amateurs who have invested a great deal of money or time in a fine-quality radio may find it more economical to extend the radio's range when new bands come available, rather than replace it. Some transceiver manufacturers are supportive of add-on transverters, and design in circuitry and cabling attachments for them. High band use Transverters are most commonly used in amateur radio to convert radio transceivers designed for use on the HF or VHF bands to operate on even higher frequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yaesu FT-847
is a district in Chūō, Tokyo, Japan, located north of Ginza, west of Nihonbashi and Kyōbashi, and adjacent to the east side of Tokyo Station. The Yaesu exit of this station, which faces Nihonbashi, is recent and primarily provides access to the Shinkansen platforms. History The area was named after the 17th century Dutch adventurer Jan Joosten van Lodensteijn, or simply Jan Joosten. For his services to Tokugawa Ieyasu he was granted a house in Edo (now Tokyo) in an area that came to be called "Yayosu Quay" after him — his name was pronounced ''yan yōsuten'' in Japanese (short version: Yayōsu (耶楊子)) — the Yaesu side of Tokyo Station is also named for him. Yaesu Avenue has a monument dedicated to Jan Joosten and his life after his arrival in Japan on ''De Liefde'' with his shipmate William Adams. Ukiyo-e artist Andō Hiroshige was born in the Yayosu barracks in the Yaesu area in 1797. Places in Yaesu *Tokyo Station and highway bus platforms * Yaesu underground ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICOM IC-7300
The ICOM IC-7300 is a multimode 6 meter and HF base station amateur radio transceiver. The IC-7300 was announced to the public at the Japan Ham Fair in 2015. The radio has 100 watts output on CW, SSB, and FM modulations and 25 watts of output in AM. Although not the first SDR radio on the market The IC-7300 was the first mass-produced mainstream amateur radios to use SDR technology instead of the older superheterodyne transceiver design. Designed to replace the older IC-746PRO the IC-7300 is smaller and significantly lighter than its predecessor. Like many other radios of its class the IC-7300 has an internal antenna tuner and contains an internal audio card accessible over USB. This allows the radio to be used for popular digital modes such as PSK31, Winlink, and FT8. The radio has received praise for its easy to use menus, large readable screen, and excellent audio processing. Specifications Specifications of the ICOM IC-7300 are: * Frequency range: Tx: 1.8 – 54&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICOM IC-7100
The ICOM IC-7100 is a multimode HF/VHF/UHF mobile amateur radio transceiver. The IC-7100 has support for a wide variety of commonly used amateur radio modes including ICOMs proprietary digital voice mode DSTAR. Additionally the radio offers 100 watts on HF, 50 watts on VHF, and 35 watts on UHF. The IC-7100 is unique in that it has a large detachable control head with a slanted display so the transmitter can be installed elsewhere in a vehicle or home. The receiver used in the IC-7100 is a triple conversion superheterodyne and has exachellet DSP and audio filters. The IC-7100 allows for connection to a computer over USB which enables the radio to be used for popular digital modes such as FT8, Winlink, and Packet Operation. Locations of nearby repeaters and sending APRS locations can be done with an optional GPS The Global Positioning System (GPS), originally Navstar GPS, is a Radionavigation-satellite service, satellite-based radionavigation system owned by the United St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Private Mobile Radio
Professional mobile radio (also known as private mobile radio (PMR) in the UK) are person-to-person two-way radio voice communications systems which use portable, mobile, base station, and dispatch console radios. PMR radio systems are based on such standards as MPT-1327, TETRA, APCO 25, and DMR which are designed for dedicated use by specific organizations, or standards such as NXDN intended for general commercial use. These systems are used by police, fire, ambulance, and emergency services, and by commercial firms such as taxis and delivery services. Most systems are half-duplex, in which multiple radios share a common radio channel, and only one can transmit at a time. Transceivers are normally in receive mode, the user presses a push-to-talk button on his microphone when he wants to talk, which turns on his transmitter and turns off his receiver. They use channels in the VHF and UHF bands, giving them a limited range, usually depending on terrain. Output power is typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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