The S-Phone system was a UHF duplex radiotelephone system developed during World War II for use by Special Operations Executive agents working behind enemy lines to communicate with friendly aircraft and coordinate landings and the dropping of agents and supplies. The system was composed of a "Ground" transceiver, designed by Captain Bert Lane, and an "Air" transceiver designed by Major Hobday, both of the Royal Signals. [1]
The "Ground" set - which was to be used by agents on the ground - weighed about 15 pounds (6.8 kg) including batteries and was typically worn attached to its operator with two canvas straps. It was a highly directional unit which required the operator to face the path of the aircraft. It had the useful trait that transmitted signals could not be picked up by ground monitoring stations more than one mile distant; however, its signal was only good to 10,000 feet (3,000 m), which brought the aircraft within range of flak. It permitted direct two-way voice communication with an aircraft up to a range of 30 miles (48 km). While the S-Phone provided directional information to the pilot it gave no range information, although a pilot could tell when he was directly over the "Ground" operator because at that point no communication was possible. [2]
The primary purpose of the S-Phone was not navigational as such; rather, it was to provide a reasonably secure channel for coded conversation between staff officers based in London and agents in the field, allowing for the exchange of orders and information. The security of a circuit was sometimes tested by using an officer who could recognize whether a voice was actually that of the agent who was supposedly speaking to him.[ citation needed ]
It was designed in late 1942, using some of the component parts of the Wireless Set No.37. [3]
Use of the phone is shown in the post-war docu-drama Now It Can Be Told (aka School_for_Danger, 1946) on YouTube.
Joan-Eleanor a similar system developed for the OSS
In radio communication, a transceiver is an electronic device which is a combination of a radio transmitter and a receiver, hence the name. It can both transmit and receive radio waves using an antenna, for communication purposes. These two related functions are often combined in a single device to reduce manufacturing costs. The term is also used for other devices which can both transmit and receive through a communications channel, such as optical transceivers which transmit and receive light in optical fiber systems, and bus transceivers which transmit and receive digital data in computer data buses.
Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz ; above the medium frequency band (MF), to the bottom of the VHF band.
Wireless communication is the transfer of information (telecommunication) between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances can be short, such as a few meters for Bluetooth, or as far as millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of applications of radio wireless technology include GPS units, garage door openers, wireless computer mouse, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones. Somewhat less common methods of achieving wireless communications involve other electromagnetic phenomena, such as light and magnetic or electric fields, or the use of sound.
Air-ground radiotelephone service is a system which allows voice calls and other communication services to be made from an aircraft to either a satellite or land based network. The service operates via a transceiver mounted in the aircraft on designated frequencies. In the US these frequencies have been allocated by the Federal Communications Commission.
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A walkie-talkie, more formally known as a handheld transceiver, HT, or handheld radio, is a hand-held, portable, two-way radio transceiver. Its development during the Second World War has been variously credited to Donald Hings, radio engineer Alfred J. Gross, Henryk Magnuski and engineering teams at Motorola. First used for infantry, similar designs were created for field artillery and tank units, and after the war, walkie-talkies spread to public safety and eventually commercial and jobsite work.
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A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless and the network is distributed over land areas called cells, each served by at least one fixed-location transceiver. These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content. A cell typically uses a different set of frequencies from neighboring cells, to avoid interference and provide guaranteed service quality within each cell.
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An amateur radio station is a radio station designed to provide radiocommunications in the amateur radio service for an amateur radio operator. Radio amateurs build and operate several types of amateur radio stations, including fixed ground stations, mobile stations, space stations, and temporary field stations. A slang term often used for an amateur station's location is the shack, named after the small enclosures added to the upperworks of naval ships to hold early radio equipment and batteries.
The Rebecca/Eureka transponding radar was a short-range radio navigation system used for the dropping of airborne forces and their supplies. It consisted of two parts, the Rebecca airborne transceiver and antenna system, and the Eureka ground-based transponder. Rebecca calculated the range to the Eureka based on the timing of the return signals, and its relative position using a highly directional antenna. The 'Rebecca' name comes from the phrase "Recognition of beacons". The 'Eureka' name comes from the Greek word meaning "I have found it!".
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates oscillating electrical energy, often characterized as a wave. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications.
During World War II, the German Luftwaffe relied on an increasingly diverse array of electronic communications, IFF and RDF equipment as avionics in its aircraft and also on the ground. Most of this equipment received the generic prefix FuG for Funkgerät, meaning "radio equipment". Most of the aircraft-mounted Radar equipment also used the FuG prefix. This article is a list and a description of the radio, IFF and RDF equipment.
The Wireless Set No. 19 was a Second World War mobile radio transceiver designed for use by armoured troops of the British Army. First introduced in 1940, the No. 19 began to replace the pre-war Wireless Set No. 11. Two modified versions were introduced, Mk. II in 1941 and Mk. III in 1942. An improved version from Canada was introduced in 1942 for use primarily with other forces. In British service, the No. 19 was replaced in the post-war era by the Larkspur radio system. Canadian-built No. 19s saw continued service for many years with a variety of users.
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Aviation communication refers to the conversing of two or more aircraft. Aircraft are constructed in such a way that make it very difficult to see beyond what is directly in front of them. As safety is a primary focus in aviation, communication methods such as wireless radio are an effective way for aircraft to communicate with the necessary personnel. Aviation is an international industry and as a result involves multiple languages. The International Civil Aviation Organization (ICAO) deemed English the official language of aviation. The industry considers that some pilots may not be fluent English speakers and as a result pilots are obligated to participate in an English proficiency test.
An in-building cellular enhancement system, commonly implemented in conjunction with a distributed antenna system (DAS), is a telecommunications solution which is used to extend and distribute the cellular signal of a given mobile network operator within a building. In the United States, operators commonly supported by such solutions include AT&T Mobility, Verizon Wireless, Sprint Corporation, T-Mobile US, in addition to smaller regional carriers as required. Below ground level, large buildings and high rises are examples where mobile phones are unable to properly reach the carrier's macro or outdoor network. In these environments, the in-building cellular enhancement system will connect to the carrier's signal source which is typically a bi-directional amplifier or a base transceiver station. This signal source transmits the mobile network operator's licensed radio frequency. This frequency is then transported within the building using coaxial cable, optical fiber or Category 5e/Category 6 twisted pair cable. In-building coverage antennas are strategically placed to provide the best overall coverage for users.
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