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27-517: KZLT-FM (104.3 MHz , "Cities FM") is a radio station broadcasting an adult contemporary format. Licensed to East Grand Forks, Minnesota , it serves the Grand Forks, North Dakota metropolitan area. It first began broadcasting in 1979 under the call sign KRAD-FM . The station is currently owned by Leighton Broadcasting . The station signed on December 3, 1979 as a Class A on 103.9 as KRAD-FM, simulcasting KRAD AM 1590 (now KGFK ), and

54-552: A more detailed treatment of this and the above frequency ranges, see Electromagnetic spectrum . Gravitational waves are also described in Hertz. Current observations are conducted in the 30–7000 Hz range by laser interferometers like LIGO , and the nanohertz (1–1000 nHz) range by pulsar timing arrays . Future space-based detectors are planned to fill in the gap, with LISA operating from 0.1–10 mHz (with some sensitivity from 10 μHz to 100 mHz), and DECIGO in

81-499: Is an SI derived unit whose formal expression in terms of SI base units is s , meaning that one hertz is one per second or the reciprocal of one second . It is used only in the case of periodic events. It is named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves . For high frequencies, the unit is commonly expressed in multiples : kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of

108-577: Is equal to 6.626 070 15 × 10  J , which is equal to 4.135 667 697 × 10  eV . Photon energy is often measured in electronvolts. One electronvolt (eV) is exactly 1.602 176 634 × 10  J ‍ or, using the atto prefix, 0.160 217 6634  aJ , in the SI system . To find the photon energy in electronvolt using the wavelength in micrometres , the equation is approximately since h c / e {\displaystyle hc/e} = 1.239 841 984 ... × 10  eV⋅m where h

135-800: Is the Planck constant , c is the speed of light , and e is the elementary charge . The photon energy of near infrared radiation at 1 μm wavelength is approximately 1.2398 eV. An FM radio station transmitting at 100  MHz emits photons with an energy of about 4.1357 × 10  eV . This minuscule amount of energy is approximately 8 × 10 times the electron 's mass (via mass–energy equivalence). Very-high-energy gamma rays have photon energies of 100 GeV to over 1 PeV (10 to 10 electronvolts) or 16 nJ to 160 μJ. This corresponds to frequencies of 2.42 × 10  Hz to 2.42 × 10  Hz . During photosynthesis , specific chlorophyll molecules absorb red-light photons at

162-425: Is the photon's energy, ν is its frequency, and h is the Planck constant . The hertz is defined as one per second for periodic events. The International Committee for Weights and Measures defined the second as "the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium -133 atom" and then adds: "It follows that

189-452: Is usually measured in kilohertz (kHz), megahertz (MHz), or gigahertz (GHz). with the latter known as microwaves . Light is electromagnetic radiation that is even higher in frequency, and has frequencies in the range of tens of terahertz (THz, infrared ) to a few petahertz (PHz, ultraviolet ), with the visible spectrum being 400–790 THz. Electromagnetic radiation with frequencies in the low terahertz range (intermediate between those of

216-406: The electromagnetic spectrum . Photon energy is directly proportional to frequency. E = h f {\displaystyle E=hf} where This equation is known as the Planck relation . Additionally, using equation f = c / λ , E = h c λ {\displaystyle E={\frac {hc}{\lambda }}} where The photon energy at 1 Hz

243-449: The 0.1–10 Hz range. In computers, most central processing units (CPU) are labeled in terms of their clock rate expressed in megahertz ( MHz ) or gigahertz ( GHz ). This specification refers to the frequency of the CPU's master clock signal . This signal is nominally a square wave , which is an electrical voltage that switches between low and high logic levels at regular intervals. As

270-468: The 1970s. In some usage, the "per second" was omitted, so that "megacycles" (Mc) was used as an abbreviation of "megacycles per second" (that is, megahertz (MHz)). Sound is a traveling longitudinal wave , which is an oscillation of pressure . Humans perceive the frequency of a sound as its pitch . Each musical note corresponds to a particular frequency. An infant's ear is able to perceive frequencies ranging from 20 Hz to 20 000  Hz ;

297-537: The Cass Gilbert designed Great Northern Railway Depot in downtown Grand Forks. In late 1999, the station repositioned itself with a Hot AC format as "Cities 104.3". Lightning struck KZLT's transmitter on May 31, 2001, keeping the station off-air for a week. Cities 104.3 began broadcasting again at low-power until a new transmitter was completed in October 2001, when an 80's based classic rock format as "Z104"

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324-476: The average adult human can hear sounds between 20 Hz and 16 000  Hz . The range of ultrasound , infrasound and other physical vibrations such as molecular and atomic vibrations extends from a few femtohertz into the terahertz range and beyond. Electromagnetic radiation is often described by its frequency—the number of oscillations of the perpendicular electric and magnetic fields per second—expressed in hertz. Radio frequency radiation

351-440: The event being counted may be a complete cycle); 100 Hz means "one hundred periodic events occur per second", and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz , or a human heart might be said to beat at 1.2 Hz . The occurrence rate of aperiodic or stochastic events is expressed in reciprocal second or inverse second (1/s or s ) in general or, in

378-449: The hertz has become the primary unit of measurement accepted by the general populace to determine the performance of a CPU, many experts have criticized this approach, which they claim is an easily manipulable benchmark . Some processors use multiple clock cycles to perform a single operation, while others can perform multiple operations in a single cycle. For personal computers, CPU clock speeds have ranged from approximately 1 MHz in

405-413: The highest normally usable radio frequencies and long-wave infrared light) is often called terahertz radiation . Even higher frequencies exist, such as that of X-rays and gamma rays , which can be measured in exahertz (EHz). For historical reasons, the frequencies of light and higher frequency electromagnetic radiation are more commonly specified in terms of their wavelengths or photon energies : for

432-616: The hyperfine splitting in the ground state of the caesium 133 atom is exactly 9 192 631 770  hertz , ν hfs Cs = 9 192 631 770  Hz ." The dimension of the unit hertz is 1/time (T ). Expressed in base SI units, the unit is the reciprocal second (1/s). In English, "hertz" is also used as the plural form. As an SI unit, Hz can be prefixed ; commonly used multiples are kHz (kilohertz, 10  Hz ), MHz (megahertz, 10  Hz ), GHz (gigahertz, 10  Hz ) and THz (terahertz, 10  Hz ). One hertz (i.e. one per second) simply means "one periodic event occurs per second" (where

459-530: The late 1970s ( Atari , Commodore , Apple computers ) to up to 6 GHz in IBM Power microprocessors . Various computer buses , such as the front-side bus connecting the CPU and northbridge , also operate at various frequencies in the megahertz range. Higher frequencies than the International System of Units provides prefixes for are believed to occur naturally in the frequencies of

486-730: The quantum-mechanical vibrations of massive particles, although these are not directly observable and must be inferred through other phenomena. By convention, these are typically not expressed in hertz, but in terms of the equivalent energy, which is proportional to the frequency by the factor of the Planck constant . The CJK Compatibility block in Unicode contains characters for common SI units for frequency. These are intended for compatibility with East Asian character encodings, and not for use in new documents (which would be expected to use Latin letters, e.g. "MHz"). Photon energy Photon energy can be expressed using any energy unit . Among

513-564: The rules for capitalisation of a common noun ; i.e., hertz becomes capitalised at the beginning of a sentence and in titles but is otherwise in lower case. The hertz is named after the German physicist Heinrich Hertz (1857–1894), who made important scientific contributions to the study of electromagnetism . The name was established by the International Electrotechnical Commission (IEC) in 1935. It

540-413: The specific case of radioactivity , in becquerels . Whereas 1 Hz (one per second) specifically refers to one cycle (or periodic event) per second, 1 Bq (also one per second) specifically refers to one radionuclide event per second on average. Even though frequency, angular velocity , angular frequency and radioactivity all have the dimension T , of these only frequency is expressed using

567-528: The station rebranded itself using its call letters, "104.3 KZLT". In March 2013, the station reverted to the "Lite Rock 104.3" identity. On April 11, 2014 KZLT-FM relaunched as "104.3 Cities FM". [REDACTED] 47°48′50″N 96°55′48″W  /  47.814°N 96.930°W  / 47.814; -96.930 Hertz The hertz (symbol: Hz ) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle ) per second . The hertz

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594-480: The unit hertz. Thus a disc rotating at 60 revolutions per minute (rpm) is said to have an angular velocity of 2 π  rad/s and a frequency of rotation of 1 Hz . The correspondence between a frequency f with the unit hertz and an angular velocity ω with the unit radians per second is The hertz is named after Heinrich Hertz . As with every SI unit named for a person, its symbol starts with an upper case letter (Hz), but when written in full, it follows

621-403: The unit's most common uses are in the description of periodic waveforms and musical tones , particularly those used in radio - and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the energy of a photon , via the Planck relation E  =  hν , where E

648-404: The units commonly used to denote photon energy are the electronvolt (eV) and the joule (as well as its multiples, such as the microjoule). As one joule equals 6.24 × 10  eV , the larger units may be more useful in denoting the energy of photons with higher frequency and higher energy, such as gamma rays , as opposed to lower energy photons as in the optical and radio frequency regions of

675-490: Was adopted by the General Conference on Weights and Measures (CGPM) ( Conférence générale des poids et mesures ) in 1960, replacing the previous name for the unit, "cycles per second" (cps), along with its related multiples, primarily "kilocycles per second" (kc/s) and "megacycles per second" (Mc/s), and occasionally "kilomegacycles per second" (kMc/s). The term "cycles per second" was largely replaced by "hertz" by

702-591: Was introduced. Norman sold KZLT and KCNN to Leighton Broadcasting in 2003, and later KZLT changed back to an adult contemporary format as "Breeze 104.3". In December 2005, KZLT tweaked to a hot adult contemporary , and rebranded as "More Music 104.3", which later tweaked to Top 40 (CHR) competing with Clear Channel's heritage Top 40 station KKXL-FM "XL93". Due to inadequate ratings, KZLT reverted formats back to adult contemporary as "Lite Rock 104.3" on March 26, 2007. The station plays Christmas music annually from Thanksgiving to Christmas Day. In April 2012

729-557: Was owned by Dave Norman. The station flipped to Country Music in the 1980s as KRRK "Double R 104", and KZLT in the spring of 1985 on the 104.3 frequency. Station owner Dave Norman changed the format to light Adult contemporary (AC) as "K-Lite" under the KZLT call sign, increased power to 100,000 watts from a transmitter west of Fisher, Minnesota . KZLT and KCNN were moved from the transmitter/studio complex in East Grand Forks to

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