X-Nico

10 unusual facts about Frequency


Charles Camsell

The Foundation for the Study of Cycles is an international non-profit research organisation for the study of cycles of events.

Distributed element filter

Distributed element filters are used in many of the same applications as lumped element filters, such as selectivity of radio channel, bandlimiting of noise and multiplexing of many signals into one channel.

Frequency-dependent selection

Perhaps the best known early modern statement of the principle is Bryan Clarke's 1962 paper on apostatic selection (a synonym of negative frequency-dependent selection).

Frequency-hopping spread spectrum

Władysław Kozaczuk, Enigma: How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two, edited and translated by Christopher Kasparek, Frederick, MD, University Publications of America, 1984, ISBN 0-89093-547-5.

Perhaps the earliest mention of frequency hopping in the open literature is in radio pioneer Jonathan Zenneck's book Wireless Telegraphy (German, 1908, English translation McGraw Hill, 1915), although Zenneck himself states that Telefunken had already tried it.

This early version of frequency hopping used a piano-roll to change among 88 frequencies, and was intended to make radio-guided torpedoes harder for enemies to detect or to jam.

Single channel per carrier

Where multiple access is concerned, SCPC is essentially FDMA.

Single-frequency

Single-frequency network, a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel

Single-frequency signaling, line signaling in which dial pulses or supervisory signals are conveyed by a single voice-frequency tone in each direction

Time division multiple access

In radio systems, TDMA is usually used alongside Frequency-division multiple access (FDMA) and Frequency division duplex (FDD); the combination is referred to as FDMA/TDMA/FDD.


2-meter band

Much of 2-meter FM operation uses a radio repeater, a radio receiver and transmitter that instantly retransmits a received signal on a separate frequency.

Abbey104

The main frequency for Abbey104 is on 104.7 MHz FM from a transmitter at The Gryphon School, Sherborne.

Advanced Audio Coding

AAC supports inclusion of 48 full-bandwidth (up to 96 kHz) audio channels in one stream plus 16 low frequency effects (LFE, limited to 120 Hz) channels, up to 16 "coupling" or dialog channels, and up to 16 data streams.

Amos Yarkoni

In 1955, the frequency and effectiveness of Fedayeen attacks being launched from the Egyptian-controlled Gaza Strip and the Jordanian-controlled Hebron Hills area against isolated Israeli civilian communities increased, and the IDF searched for new ways to eliminate the threat.

Archaeogenetics of the Near East

According to DNA testing, Druze are remarkable for the high frequency (35%) of males who carry the Y-chromosomal haplogroup L, which is otherwise uncommon in the Mideast (Shen et al. 2004).

Bad Dürrheim transmitter

Because the program of Deutschlandfunk could be also received well by Ravensburg-Horgenzell transmitter in the area, which Bad Dürrheim transmitter served, it was shut down after the wave plan of Geneva came into force in 1978, where no frequency was applied for it.

Barkhausen–Kurz tube

After the development by Lee de Forest of the triode vacuum tube in 1906, it was realized that the upper frequency at which the device could be used was limited by the spacing between internal components.

Black ghost knifefish

On the other hand, when low-frequency electric fields are generated by external sources instead of the fish itself, a different class of electroreceptor organs is used for this passive electrolocation, called ampullary organs.

Capacitor

Leyden jars or more powerful devices employing flat glass plates alternating with foil conductors were used exclusively up until about 1900, when the invention of wireless (radio) created a demand for standard capacitors, and the steady move to higher frequencies required capacitors with lower inductance.

Capital Manchester

The 102 MHz frequency in Manchester has a chequered background, initially it was occupied by Sunset 102 which included regular shows from house music innovators 808 State and a Saturday evening rave show from Sammy B; both were cited by Dave Haslam in City Life to have been instrumental in reflecting and developing the early rave culture in the city.

CBPM

CBPM is a Weatheradio Canada station which broadcasts weather information and alerts on a frequency of 1260 AM in Sicamous, British Columbia, Canada, in both English and French.

CJDL-FM

The request was denied, and the frequency ultimately went to CFRS (Now CHCD-FM) in nearby Simcoe, Ontario.

CKCX-SW

The site was capable of utilizing 500 kW transmitters, but the end of the Cold War and improved shortwave frequency coordination made upgrading to 500 kW unnecessary.

Coburn Hill

The following radio stations, in order of frequency, broadcast from the hill: KLMT 88.9 FM, KBLW 90.1 FM, K213DY 90.5 FM, KLRV 90.9 FM, K217CM 91.3 FM, KBXI 92.5 FM, KURL 93.3 FM, KRZN 96.3 FM, KKBR 97.1 FM, K248BL 97.5 FM, K259AN 99.7 FM, KRSQ 101.9 FM, KCTR 102.9 FM, KMHK 103.7 FM, KYSX 105.1 FM, KPLN 106.7 FM, KRPM 107.5 FM.

Constant-weight code

Binary constant-weight codes have several applications, including frequency hopping in GSM networks.

Gastrointestinal stromal tumor

These include, in descending order of frequency, neurofibromatosis Recklinghausen (NF-1), Carney's triad (gastric GIST, pulmonary chondroma and extra-adrenal paraganglioma), germline gain-of-function mutations in c-Kit/PDGFRA, and the Carney-Stratakis syndrome.

Gibson City, Illinois

WGCY is an FM station licensed to Gibson City broadcasting at a frequency of 106.3 mHz.

Head-related transfer function

HRTF describes how a given sound wave input (parameterized as frequency and source location) is filtered by the diffraction and reflection properties of the head, pinna, and torso, before the sound reaches the transduction machinery of the eardrum and inner ear (see auditory system).

Intercom

Multiple channels of simultaneous conversations can be carried over additional conductors within a cable or by frequency- or time-division multiplexing in the analogue domain.

Internal clock

Clock rate, the frequency of an electronic oscillator (such as an oscillator crystal) used by computer processor

James Wyatt

As early as 1790, when he was invited to submit designs for rebuilding St Chad's Church at Shrewsbury, he broke his engagements with such frequency that the committee "became at length offended, and addressed themselves to Mr. George Stewart".

John Pendry

In 2006 he came up with the idea of bending light in such a way that it could form a container around an object which effectively makes the object invisible and produced a paper with David R. Smith who demonstrated the idea at the frequency of microwaves.

JPEG

Next, each 8×8 block of each component (Y, Cb, Cr) is converted to a frequency-domain representation, using a normalized, two-dimensional type-II discrete cosine transform (DCT), which was introduced by N. Ahmed, T. Natarajan and K. R. Rao in 1974; see Citation 1 in Discrete cosine transform.

K31GL-D

Marcos A. Rodriguez acquired the frequency in 1994 and ran Spanish music video programming on it 24 hours a day.

KGGG-FM

However, on November 24, 2010, after the FAA "had previously imposed a condition on the tower owner to coordinate any new frequencies on the tower," Connoisseur cancelled its CP and the FCC deleted the 107.7 FM frequency.

Laplace transform

The wide and general applicability of the Laplace transform and its inverse is illustrated by an application in astronomy which provides some information on the spatial distribution of matter of an astronomical source of radiofrequency thermal radiation too distant to resolve as more than a point, given its flux density spectrum, rather than relating the time domain with the spectrum (frequency domain).

London Buses route 108

Since takeover by Harris, the 108 has been diverted via North Greenwich, but reverted to a more direct route across Blackheath via Prince of Wales Road; the frequency has been further enhanced to every 10 minutes, utilising four earlier Excels made redundant by the loss of car park services at Lakeside Shopping Centre, but this is still not as good as the 5 minute double deck service provided in 1933.

Midwoofer-tweeter-midwoofer

The midwoofer-tweeter-midwoofer loudspeaker configuration (called MTM, for short) was created by Joseph D'Appolito as a way of correcting the inherent lobe tilting of a typical mid-tweeter (MT) configuration, at the crossover frequency, unless time-aligned.

Parametric oscillator

Michael Faraday (1831) was the first to notice oscillations of one frequency being excited by forces of double the frequency, in the crispations (ruffled surface waves) observed in a wine glass excited to "sing".

RAF Ringway

Comedian Frank Muir, spent several years at the school in the photographic section taking slow motion film of jumps on a project intended to decrease the frequency of parachutes failing (sometimes called "Roman Candle").

Rome Laboratory

One of their earliest experiments involved the construction of the Forestport Tower, a 1205 foot high transmission antenna used for low-frequency communications experiments.

Sandringham railway line

The Cain Labor government in the 1980s proposed rebuilding the line as a light rail line, but since then patronage has grown considerably and even with the 8-minute peak-period frequency, trains are heavily loaded.

Sensory substitution

The frequency and the inter-aural disparity are determined by the center of gravity of the co-ordinates of the receptive field's pixels in the image (see "There is something out there: distal attribution in sensory substitution, twenty years later"; Auvray M., Hanneton S., Lenay C., O'Regan K. Journal of Integrative Neuroscience 4 (2005) 505-21).

Serbians

The term Srbijanci is not part of the modern Serbian mainstream language as its frequency and usage is minimal.

Single-phase generator

Neckarwestheim I in Neckarwestheim is a unique nuclear power plant in that it is equipped with high-capacity single-phase generators to supply Deutsche Bahn railway with specific AC voltage at frequency of 16 2/3 Hz.

St Kilda–Fremantle AFL controversies

Contests between the two clubs since Fremantle's admission in 1995 have a particularly high frequency of controversial and unusual events.

Terrestrial television

By the mid 1990s, the interest in digital television across Europe was such the CEPT convened the "Chester '97" conference to agree means by which digital television could be inserted into the ST61 frequency plan.

Voltage and frequency scaling

Dynamic frequency scaling, a technique in computer architecture whereby the frequency of a microprocessor can be automatically adjusted "on the fly," either to conserve power or to reduce the amount of heat generated by the chip

WCXG

The 89.9 frequency had been used by WEHB (East Hills Broadcasters) for a number of years, broadcasting (in mono) from a tower on the Aquinas College campus, with studios above the Intersection bar.

West Midlands bus routes 394 and 395

National Express West Midlands (NXWM) operate service 10, between Walsall and Burntwood and the 10A, between Walsall and Brownhills West/Ogley Hay at twenty-minute frequencies, giving a combined frequency of every 10 minutes.

Westerglen transmitting station

A number of items in the BBC Radio 4 schedule are carried on the longwave frequency only: these include Yesterday In Parliament at 0835–0900 on Tuesdays to Fridays, The Daily Service at 0945–1000 on Mondays to Fridays, the Shipping Forecast at 1201–1204 daily and 1754–1757 on Mondays to Fridays, and Test Match Special during international cricket games.

WETR

Because it shares the same frequency with WJR in Detroit, Michigan, WETR operates during the daytime hours only.

WFMG

However, this may change as another pending frequency move -- WKSW Urbana into the Dayton metro -- may have further impact on the station's reception to the east of Richmond if approved.

WFXR

The channel 27 frequency in Roanoke was originally home to WROV-TV, which operated for less than five months in 1953.

WGU-20

Operating 24 hours a day on a longwave frequency of 179 kHz from Chase, Maryland, WGU-20's programming consisted of pre-recorded announcements and time checks.

Wien's law

Wien approximation, an equation used to describe the short-wavelength (high frequency) spectrum of thermal radiation

WPZE

The frequency already belonged to WGHR in Marietta, the student radio station at what is now Southern Polytechnic State University — however the forced downgrade to second-class status left the class D station vulnerable.

WUBL

The name was "FM95 WPCH" until mid-1991, when the "Peach 94.9" name was adopted, reflecting its exact frequency for newer radios with digital tuning, and Atlanta's nickname as the "Big Peach".

WXCT

The 990 frequency signed on in 1969 as WNTY, a daytime-only station that targeted Southington and nearby Bristol.