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 of Canada. Chu may refer to: Surname A common Chinese surname Places Chu River in modern Kyrgyzstan and Kazakhstan Chu, Kazakhstan, a city in Kazakhstan A popular unofficial name for the Hubei Province and Hunan Province in the Peoples Republic of China States Chu (Ten Kingdoms), a kingdom during the Period... In the United States (and potentially elswhere), each radio station or TV station is assigned a city of license by the Federal Communications Commission that they must serve. While this has become far less meaningful over the decades, stations are still required to post their public file somewhere within the... For other uses, see Frequency (disambiguation). ... A radio format or programming format describes the overall content broadcast on a radio station. ... Nominal power is a measurement of a mediumwave radio stations output used in the United States. ... The National Research Council of Canada (NRC) is Canadas leading organization for scientific research and development. ... A website (alternatively, Web site or web site) is a collection of Web pages, images, videos or other digital assets that is hosted on one or several Web server(s), usually accessible via the Internet, cell phone or a LAN. A Web page is a document, typically written in HTML... Call sign can refer to different types of call signs: Airline call sign Aviator call sign Cosmonaut call sign Radio and television call signs Tactical call sign, also known as a tactical designator See also: International Callsign Allocations, Maritime Mobile Service Identity This is a disambiguation page — a navigational aid... A solid-state, analog shortwave receiver Shortwave radio operates between the frequencies of 3 MHz (3,000 kHz) and 30 MHz (30,000 kHz) [1] and came to be referred to as such in the early days of radio because the wavelengths associated with this frequency range were shorter than... A time signal is a visible, audible, mechanical, or electronic signal used as a reference to determine the time of day. ... The National Research Council of Canada (NRC) is Canadas leading organization for scientific research and development. ...

History

The station was started in 1929 by the Dominion Observatory in Ottawa, Ontario, Canada. It was operated by the Observatory until 1970. The call letters CHU were assigned in 1938. Until then, the call was VE9OB. Year 1929 (MCMXXIX) was a common year starting on Tuesday (link will display the full calendar) of the Gregorian calendar. ... The Dominion Observatory building The Dominion Observatory was an astronomical observatory in Ottawa, Canada that operated from 1905 to 1970. ... This article is about the capital city of Canada. ... Year 1970 (MCMLXX) was a common year starting on Thursday (link shows full calendar) of the Gregorian calendar. ... Year 1938 (MCMXXXVIII) was a common year starting on Saturday (link will display the full calendar) of the Gregorian calendar. ...

Broadcast format

CHU's signal is used for continuous dissemination of official Canadian government time signals. Unlike other time stations, time signals are the only type of information broadcast from this station. A time signal is a visible, audible, mechanical, or electronic signal used as a reference to determine the time of day. ...

The CHU time signal and radio frequencies are derived from atomic clocks. “Nuclear Clock” redirects here. ...

CHU will acknowledge listeners' reception reports. A 1969 Radio Moscow QSL card QSL, or QSL card, is the confirmation of a QSO (a radio contact) between two radio amateurs. ...

A similar time signal from the National Research Council is used by CBC radio services daily at noon ET on Radio-Canada's La Première Chaîne, and 1pm ET on CBC Radio One.-1... -1... Radio-Canada redirects here. ... La Première Chaîne is the news and information service of la Société Radio-Canada, the French-language public broadcaster in Canada. ... CBC Radio One is the English language news and information radio network of the publicly-owned Canadian Broadcasting Corporation. ...

Transmission system

CHU transmits 3 kW signals on 3330 and 14670 kHz, and a 10 kW signal on 7335 kHz. The signal is amplitude modulated, with the lower sideband suppressed (emission type H3E). The same information is carried on all three frequencies simultaneously. Kwai Lo is Chinese slang for foreigner or ghost person. ... A kilohertz (kHz) is a unit of frequency equal to 1,000 hertz (1,000 cycles per second). ... Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. ... In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, containing energy as a result of the modulation process. ... The International Telecommunication Union uses a special system for classifying radio frequency signals. ...

The CHU transmitter is located at 45°17′47″N, 75°45′22″W, near Barrhaven, Ontario, 15 km southwest of Ottawa's central business district. A group of homes in Barrhaven Barrhaven is a rapidly growing suburban area located in the southwest corner of the city of Ottawa, Ontario, Canada, about 20 km (12 miles) southwest of downtown Ottawa. ... This article is about the capital city of Canada. ...

The systems feeding the transmitters are duplicated for reliability, and have both battery and generator protection. The generator can also supply the transmitters. The announcements are made using digitally recorded voices. Individual vertical dipole antennas are used for each frequency. A simple half-wave dipole antenna that a shortwave listener might build. ...

CHU has long been licensed as "fixed service" within the band allocations of the International Telecommunications Union. Recently, allocation changes threatened CHU's use of 7.335 MHz. CHU was faced with either discontinuing the use of this frequency or relicensing it as a broadcast station by April 2007. CHU user input was sought with the following message transmitted each minute, alternating between English and French:^{[citation needed]} The International Telecommunication Union (ITU) is an international organization established to standardize and regulate international radio and telecommunications. ...

"On April 1, 2007, CHU needs to stop operating, change frequencies, or relicense. Contact radio.chu@nrc.gc.ca or mail CHU Canada K1A 0R6."

On February 24, 2007, it was observed that the announcement had been updated to "CHU has been licensed to continue broadcasting on 7.335 MHz." This announcement alternated between English and French. (This was heard on CHU's operating frequency of 7.335 MHz.)

On February 26, 2007, it was observed that all announcements regarding relicensing had been discontinued. (This was heard on CHU's operating frequency of 7.335 MHz.)

Time signal format

The actual time signal is a series of 300 ms-long 1000 Hz tones, transmitted once per second, on the second. The top of the minute is marked by a half-second-long beep, and the top of the hour is marked with a one second-long beep, followed by nine seconds of silence. Thereafter, every second except for the 29th second past the minute, CHU transmits a 300-millisecond tone. Between one and sixteen seconds past the minute, CHU transmits the difference between UT1 and Coordinated Universal Time (UTC) by using split tones. Universal Time (UT) is a timescale based on the rotation of the Earth. ... UTC redirects here. ...

Between 31 and 39 seconds past the minute inclusive, the once-per-second tones are reduced to 10-millisecond "ticks" while a digital time code is transmitted. The digital time code used by CHU is unique, in that it is decodeable by a Bell 103-compatible modem.^[1] The Bell 103 modem was the first commercial modem for computers, released by AT&T in 1962. ...

At ten seconds before each minute, the once-per-second tones are again cut to 10 milliseconds each, this time while CHU transmits a brief voice station identification, followed by voice announcements of the next minute in UTC, alternating between French and English. French announcements are transmitted first on the odd minutes, while English announcements come first on the even minutes. The English language is a West Germanic language that originates in England. ...

Western Canada signal coverage

Proposed CHU transmitter for Western Canada

CHU often cannot be received in Western Canada, on any frequency. Sometimes this is simply because of the significant level of noise produced by the electrical wiring in a building. For most of Western Canada, terrestrial interference and weak signals make CHU practically unusable. Image File history File links Size of this preview: 790 × 600 pixelsFull resolution (885 × 672 pixel, file size: 29 KB, MIME type: image/png) I am making these VOACAP HF area coverage calculations public so as to help users better understand the use of the VOACAP program. ... Image File history File links Size of this preview: 790 × 600 pixelsFull resolution (885 × 672 pixel, file size: 29 KB, MIME type: image/png) I am making these VOACAP HF area coverage calculations public so as to help users better understand the use of the VOACAP program. ...

Subject to limitations of their own, WWV and WWVH are the fallback in Western Canada as far as getting time signals via shortwave is concerned. WWV Transmitter Building WWV is the callsign of NISTs shortwave radio station located in Fort Collins, Colorado. ... WWVH is the callsign of NISTs shortwave radio time signal station in Kekaha, on the island of Kauai in the state of Hawaii. ...

A proposal has been published to create a companion time signal station for Western Canada.^[2] Proposed coverage is shown in the graphic.

References

Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 328th day of the year (329th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 36th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 328th day of the year (329th in leap years) in the Gregorian calendar. ...

External links

• NRC Short Wave Station Broadcasts (CHU)