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The angular wavenumber may be expressed in the unit radian per meter (rad⋅m −1), or as above, since the radian is dimensionless. For electromagnetic radiation in vacuum, wavenumber is directly proportional to frequency and to photon energy. Because of this, wavenumbers are used as a convenient unit of energy in spectroscopy.
The 1.25-meter, 220 MHz or 222 MHz band is a portion of the VHF radio spectrum internationally allocated for amateur radio use on a primary basis in ITU Region 2, and it comprises frequencies from 220 MHz to 225 MHz. [1]
Shortwave bands are frequency allocations for use within the shortwave radio spectrum (the upper medium frequency [MF] band and all of the high frequency [HF] band). Radio waves in these frequency ranges can be used for very long distance (transcontinental) communication because they can reflect off layers of charged particles in the ionosphere and return to Earth beyond the horizon, a ...
the maximum modulation frequency (or range of modulation frequencies) of an optical modulator; the range of frequencies in which some measurement apparatus (e.g., a power meter) can operate; the data rate (e.g., in Gbit/s) achieved in an optical communication system; see bandwidth (computing).
The phase velocity at which electrical signals travel along a transmission line or other cable depends on the construction of the line. Therefore, the wavelength corresponding to a given frequency varies in different types of lines, thus at a given frequency different conductors of the same physical length can have different electrical lengths.
The 15-meter band (also called the 21-MHz band or 15 meters) is an amateur radio frequency band spanning the shortwave spectrum from 21 to 21.45 MHz. The band is suitable for amateur long-distance communications , and such use is permitted in nearly all countries.
A Yaesu FT-857D tuned to 50.125 MHz, the traditional 6-meter single-sideband calling frequency in the United States. [1] The 6-meter band is the lowest portion of the very high frequency (VHF) radio spectrum (50.000-54.000 MHz) internationally allocated to amateur radio use. The term refers to the average signal wavelength of 6 meters. [a]
A frequency meter is an instrument that displays the frequency of a periodic electrical signal. Various types of mechanical frequency meters were used in the past, but since the 1970s these have almost universally been replaced by digital frequency counters .