A radio clock or radio-controlled clock (RCC), and often colloquially referred to as an "atomic clock", is a type of quartz clock or watch that is automatically synchronized to a time code transmitted by a radio transmitter connected to a time standard such as an atomic clock. Such a clock may be synchronized to the time sent by a single transmitter, such as many national or regional time transmitters, or may use the multiple transmitters used by satellite navigation systems such as Global Positioning System. Such systems may be used to automatically set clocks or for any purpose where accurate time is needed. Radio clocks may include any feature available for a clock, such as alarm function, display of ambient temperature and humidity, broadcast radio reception, etc.
In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band. The term is historic, dating from the early 20th century, when the radio spectrum was considered to consist of longwave (LW), medium-wave (MW), and short-wave (SW) radio bands. Most modern radio systems and devices use wavelengths which would then have been considered 'ultra-short'.
The Time from NPL is a radio signal broadcast from the Anthorn Radio Station near Anthorn, Cumbria, which serves as the United Kingdom's national time reference. The time signal is derived from three atomic clocks installed at the transmitter site, and is based on time standards maintained by the UK's National Physical Laboratory (NPL) in Teddington. The service is provided by Babcock International, under contract to the NPL. It was funded by the former Department for Business, Innovation and Skills; as of 2017 NPL Management Limited (NPLML) was owned by the Department for Business, Energy and Industrial Strategy (BEIS), and NPL operated as a public corporation.
CHU is the call sign of a shortwave time signal radio station operated by the Institute for National Measurement Standards of the National Research Council. CHU's signal is used for continuous dissemination of official Canadian government time signals, derived from atomic clocks.
WWV is a shortwave radio station, located near Fort Collins, Colorado. It has broadcast a continuous time signal since 1945, and implements United States government frequency standards, with transmitters operating on 2.5, 5, 10, 15, and 20 MHz. WWV is operated by the U.S. National Institute of Standards and Technology (NIST), under the oversight of its Time and Frequency Division, which is part of NIST's Physical Measurement Laboratory based in Gaithersburg, Maryland.
WWVB is a time signal radio station near Fort Collins, Colorado and is operated by the National Institute of Standards and Technology (NIST). Most radio-controlled clocks in North America use WWVB's transmissions to set the correct time.
JJY is the call sign of a low frequency time signal radio station located in Japan.
DCF77 is a German longwave time signal and standard-frequency radio station. It started service as a standard-frequency station on 1 January 1959. In June 1973 date and time information was added. Its primary and backup transmitter are located at 50°0′56″N9°00′39″E in Mainflingen, about 25 km south-east of Frankfurt am Main, Germany. The transmitter generates a nominal power of 50 kW, of which about 30 to 35 kW can be radiated via a T-antenna.
In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. The antenna intercepts radio waves and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation.
In a radio receiver, a beat frequency oscillator or BFO is a dedicated oscillator used to create an audio frequency signal from Morse code radiotelegraphy (CW) transmissions to make them audible. The signal from the BFO is mixed with the received signal to create a heterodyne or beat frequency which is heard as a tone in the speaker. BFOs are also used to demodulate single-sideband (SSB) signals, making them intelligible, by essentially restoring the carrier that was suppressed at the transmitter. BFOs are sometimes included in communications receivers designed for short wave listeners; they are almost always found in communication receivers for amateur radio, which often receive CW and SSB signals.
A tuner is a subsystem that receives radio frequency (RF) transmissions, such as FM broadcasting, and converts the selected carrier frequency and its associated bandwidth into a fixed frequency that is suitable for further processing, usually because a lower frequency is used on the output. Broadcast FM/AM transmissions usually feed this intermediate frequency (IF) directly into a demodulator that converts the radio signal into audio-frequency signals that can be fed into an amplifier to drive a loudspeaker.
Anthorn Radio Station is a naval and government radio transmitting station located near Anthorn, Cumbria, England, overlooking the Solway Firth, and is operated by Babcock International. It has three transmitters: one VLF; one LF; and an eLORAN transmitter.
The G-Shock is a line of watches manufactured by the Japanese electronics company Casio, designed to resist mechanical stress, shock and vibration. G-Shock is an abbreviation for Gravitational Shock. The watches in the G-Shock line are designed primarily for sports, military and outdoors-oriented activities; all G-Shocks have a chronograph feature, 200 metre water resistance and an alarm, with either a digital display, analogue display or a combination of analogue and digital displays. Other features such as a countdown timer, world clock, and a backlight are included in most models. Newer high-end models in the line also feature GPS, directional, pressure and temperature sensors, radio-controlled time adjustment and Bluetooth time adjustment achieved by connecting the watch to a smartphone via a dedicated application.
Citizen Watch Co., Ltd. is an electronics company primarily known for its watches and is the core company of a Japanese global corporate group based in Nishitokyo, Tokyo, Japan. In addition to Citizen brand watches, it is the parent of American watch company Bulova, and is also known for manufacturing small electronic devices such as calculators.
ALS162 is a French longwave time signal and standard-frequency radio station and is used for the dissemination of the Metropolitan French national legal time to the public. TéléDiffusion de France broadcast the ALS162 time signal, provided by LNE-SYRTE and LNE-LTFB time laboratories under ANFR responsibility, from the Allouis longwave transmitter at 162 kHz, with a power of 800 kW.
The Master of G is a line of G-Shock watches produced by Japanese electronics company Casio designed for usage in harsh environments. Many showcase new technology that Casio would eventually introduce into the G-Shock line of watches, such as an altimeter, digital compass and the Tough Solar feature.
Quartz clocks and quartz watches are timepieces that use an electronic oscillator regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks and watches are at least an order of magnitude more accurate than mechanical clocks. Generally, some form of digital logic counts the cycles of this signal and provides a numerical time display, usually in units of hours, minutes, and seconds.
RBU is a time code radio station located in Moscow. It transmits a continuous 10 kW time code on 66⅔ kHz. This is commonly written as 66.66 or 66.666 kHz, but is actually 200/3 kHz. Until 2008, the transmitter site was near Kupavna 55°44′04″N38°9′0″E and used as antenna three T-antennas spun between three 150 metres tall grounded masts. In 2008, it has been transferred to the Taldom transmitter at 56°44′00″N37°39′48″E.
The JUNGHANS MEGA was "the world's first radio-controlled wristwatch with hands" in 1991. It was produced by the German watchmaker Junghans, who had already introduced a digital watch called Mega 1 to the market in 1990.
