In amateur radio, QRP operation refers to transmitting at reduced power while attempting to maximize one's effective range. The term QRP derives from the standard Q code used in radio communications, where "QRP" and "QRP?" are used to request, "Reduce power", and ask "Should I reduce power?" respectively. The opposite of QRP is QRO, or high-power operation.
Automatic Link Establishment, commonly known as ALE, is the worldwide de facto standard for digitally initiating and sustaining HF radio communications. ALE is a feature in an HF communications radio transceiver system that enables the radio station to make contact, or initiate a circuit, between itself and another HF radio station or network of stations. The purpose is to provide a reliable rapid method of calling and connecting during constantly changing HF ionospheric propagation, reception interference, and shared spectrum use of busy or congested HF channels.
Communications security is the discipline of preventing unauthorized interceptors from accessing telecommunications in an intelligible form, while still delivering content to the intended recipients.
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction.
Shortwave radio is radio transmission using shortwave radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), and generally extends from 1.7–30 MHz (176.3–10.0 m); from the high end of the medium frequency band (MF) just above the mediumwave AM broadcast band, to the end of the HF band.
Rockwell Collins was a multinational corporation company headquartered in Cedar Rapids, Iowa providing avionics and information technology systems and services to government agencies and aircraft manufacturers. The company was merged with UTC Aerospace Systems on November 27, 2018, and now operates as part of Collins Aerospace.
Earth–Moon–Earth communication (EME), also known as moon bounce, is a radio communications technique that relies on the propagation of radio waves from an Earth-based transmitter directed via reflection from the surface of the Moon back to an Earth-based receiver.
Conexant Systems, Inc. was an American-based software developer and fabless semiconductor company. They provided products for voice and audio processing, imaging and modems. The company began as a division of Rockwell International, before being spun off as a public company. Conexant itself then spun off several business units, creating independent public companies which included Skyworks Solutions and Mindspeed Technologies.
Secure voice is a term in cryptography for the encryption of voice communication over a range of communication types such as radio, telephone or IP.
The Hallicrafters Company manufactured, marketed, and sold radio equipment, and to a lesser extent televisions and phonographs, beginning in 1932. The company was based in Chicago, Illinois, United States.
In electronics, a local oscillator (LO) is an electronic oscillator used with a mixer to change the frequency of a signal. This frequency conversion process, also called heterodyning, produces the sum and difference frequencies from the frequency of the local oscillator and frequency of the input signal. Processing a signal at a fixed frequency gives a radio receiver improved performance. In many receivers, the function of local oscillator and mixer is combined in one stage called a "converter" - this reduces the space, cost, and power consumption by combining both functions into one active device.
A United States defense standard, often called a military standard, "MIL-STD", "MIL-SPEC", or (informally) "MilSpecs", is used to help achieve standardization objectives by the U.S. Department of Defense.
Multiple frequency-shift keying (MFSK) is a variation of frequency-shift keying (FSK) that uses more than two frequencies. MFSK is a form of M-ary orthogonal modulation, where each symbol consists of one element from an alphabet of orthogonal waveforms. M, the size of the alphabet, is usually a power of two so that each symbol represents log2M bits.
A communications receiver is a type of radio receiver used as a component of a radio communication link. This is in contrast to a broadcast receiver which is used to receive radio broadcasts. A communication receiver receives parts of the radio spectrum not used for broadcasting, that includes amateur, military, aircraft, marine, and other bands. They are often used with a radio transmitter as part of a two way radio link for shortwave radio or amateur radio communication, although they are also used for shortwave listening.
D-STAR is a digital voice and data protocol specification for amateur radio. The system was developed in the late 1990s by the Japan Amateur Radio League and uses minimum-shift keying in its packet-based standard. There are other digital modes that have been adapted for use by amateurs, but D-STAR was the first that was designed specifically for amateur radio.
The R-390A /URR is a general coverage HF radio communications receiver designed by Collins Radio Company for the US military.
NXDN is an open standard for public land mobile radio systems, that is systems of two way radios (transceivers) for bidirectional person-to-person voice communication, exclusively for use by police, fire, ambulance and other public safety organizations. It was developed jointly by Icom Incorporated and Kenwood Corporation. It is an advanced digital system using FSK modulation that supports encrypted transmission and data as well as voice transmission. Like other land mobile systems, NXDN systems use the VHF and UHF frequency bands.
WJDI was a pirate radio station. It was located in Cottekill, New York from 1989 to 1996. It was one of the pioneering & most successful pirate stations, known as "The Pirate King". Despite being a pirate radio, the station was a member of the National Radio Club. This made a lasting impression on so many DXers across the world.
