The Collins 207B-1 was a radio transmitter manufactured in 1951 by Collins Radio Company.
The Collins 207B-1 was a radio transmitter manufactured in 1951 by Collins Radio Company.
The 207B-1 was capable of 35 kilowatts of RF output in amplitude modulation mode, and 50 kilowatts in continuous wave mode. The transmitter was designed for land-based operation within the frequencies of 4 to 26 MHz and was contained within five sheet metal cabinets bolted together to form a single unit with a weight of 16,800 pounds. Intended primarily for high speed telegraphy and broadcasting, the 207B-1 was capable of high power AM transmission and telegraphic or frequency-shift keying at speeds greater than 400 words per minute. It could also be used to amplify the power output of a single-sideband modulation transmitter to a peak envelope power of 30 kilowatts. [1] [2]
In April 1951 the United States Coast Guard Cutter USCGC Courier was equipped with two 207B-1 transmitters during its time as a ship-borne radio relay station to transmit Voice of America programs behind the Iron Curtain. [3] [4]
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 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.
In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of modulation used to transmit information, such as an audio signal, by radio waves. A refinement of amplitude modulation, it uses transmitter power and bandwidth more efficiently. Amplitude modulation produces an output signal the bandwidth of which is twice the maximum frequency of the original baseband signal. Single-sideband modulation avoids this bandwidth increase, and the power wasted on a carrier, at the cost of increased device complexity and more difficult tuning at the receiver.
Frequency-shift keying (FSK) is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier signal. The technology is used for communication systems such as telemetry, weather balloon radiosondes, caller ID, garage door openers, and low frequency radio transmission in the VLF and ELF bands. The simplest FSK is binary FSK (BFSK). BFSK uses a pair of discrete frequencies to transmit binary information. With this scheme, the 1 is called the mark frequency and the 0 is called the space frequency.
In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, that are the result of the modulation process. The sidebands carry the information transmitted by the radio signal. The sidebands comprise all the spectral components of the modulated signal except the carrier. The signal components above the carrier frequency constitute the upper sideband (USB), and those below the carrier frequency constitute the lower sideband (LSB). All forms of modulation produce sidebands.
In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves.
Digital Radio Mondiale is a set of digital audio broadcasting technologies designed to work over the bands currently used for analogue radio broadcasting including AM broadcasting—particularly shortwave—and FM broadcasting. DRM is more spectrally efficient than AM and FM, allowing more stations, at higher quality, into a given amount of bandwidth, using xHE-AAC audio coding format. Various other MPEG-4 and Opus codecs are also compatible, but the standard now specifies xHE-AAC.
Rockwell Collins was a multinational corporation headquartered in Cedar Rapids, Iowa, providing avionics and information technology systems and services to government agencies and aircraft manufacturers. It was formed when the Collins Radio Company, facing financial difficulties, was purchased by Rockwell International in 1973. In 2001, the avionics division of Rockwell International was spun off to form the current Rockwell Collins, Inc, retaining its name.
The Rheinsender is a large medium-wave transmission facility near Wolfsheim, southwest of Mainz for the frequency 1017 kHz. The Rhine transmitter was established in 1950 and went on the air May 15, 1950. It belongs to SWR and transmitted until the middle of the 1990s with 600 kilowatts. In the last years the transmission power was reduced to 100 kilowatts.
NAVTEX, sometimes styled Navtex or NavTex, is an international automated medium frequency direct-printing service for delivery of navigational and meteorological warnings and forecasts, as well as urgent maritime safety information (MSI) to ships.
FM broadcasting is a method of radio broadcasting using frequency modulation (FM). Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high fidelity sound over broadcast radio. FM broadcasting is capable of higher fidelity—that is, more accurate reproduction of the original program sound—than other broadcasting technologies, such as AM broadcasting. It is also less susceptible to common forms of interference, reducing static and popping sounds often heard on AM. Therefore, FM is used for most broadcasts of music or general audio. FM radio stations use the very high frequency range of radio frequencies.
The USCGC Courier (WAGR/WTR-410) was a cutter in the United States Coast Guard converted from the M/V Coastal Messenger a Maritime Commission Type C1-M-AV1 vessel.
A radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. Radio waves are electromagnetic waves with frequencies between about 30 Hz and 300 GHz. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves. Transmitters are necessary parts of all systems that use radio: radio and television broadcasting, cell phones, wireless networks, radar, two way radios like walkie talkies, radio navigation systems like GPS, remote entry systems, among numerous other uses.
The Domžale radio transmitter is a facility for medium wave broadcasting in Domžale, in Slovenia. The transmitter is fully transistorized. It could be received easily at a medium wave frequency of 918 kHz across the whole of Europe at night-time. It was the strongest radio transmitter of the Republic of Slovenia, broadcasting the first national radio channel.
An amateur radio repeater is an electronic device that receives a weak or low-level amateur radio signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. Many repeaters are located on hilltops or on tall buildings as the higher location increases their coverage area, sometimes referred to as the radio horizon, or "footprint". Amateur radio repeaters are similar in concept to those used by public safety entities, businesses, government, military, and more. Amateur radio repeaters may even use commercially packaged repeater systems that have been adjusted to operate within amateur radio frequency bands, but more often amateur repeaters are assembled from receivers, transmitters, controllers, power supplies, antennas, and other components, from various sources.
The Vakarel Transmitter was a large broadcasting facility for long- and medium wave near Vakarel, Bulgaria. The Vakarel Transmitter was inaugurated in 1937. It had one directional antenna consisting of three guyed masts and another consisting of two masts.
A valve RF amplifier or tube amplifier (U.S.) is a device for electrically amplifying the power of an electrical radio frequency signal.
The inductive output tube (IOT) or klystrode is a variety of linear-beam vacuum tube, similar to a klystron, used as a power amplifier for high frequency radio waves. It evolved in the 1980s to meet increasing efficiency requirements for high-power RF amplifiers in radio transmitters. The primary commercial use of IOTs is in UHF television transmitters, where they have mostly replaced klystrons because of their higher efficiencies and smaller size. IOTs are also used in particle accelerators. They are capable of producing power output up to about 30 kW continuous and 7 MW pulsed and gains of 20–23 dB at frequencies up to about a gigahertz.
The 74A4 and KWS-1 is an amateur radio receiver and transmitter pair made by the Collins Radio Company of Cedar Rapids, Iowa that were introduced in 1955. They were designed to operate using the then new single-sideband (SSB) voice modulation as well as CW and AM modes. They were influential in popularizing SSB.
R-158 (Р-158) is a portable VHF radio transceiver which entered service with the Soviet military in 1979. It was designed for use at platoon level.
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