(between frequencies)
81Pitch (music) — In musical notation, the different vertical positions of notes indicate different pitches. Pitch is an auditory perceptual property that allows the ordering of sounds on a frequency related scale.[1] Pitches are compared as higher and lower in… …
82Audio crossover — A passive 2 way crossover designed to operate at loudspeaker voltages Audio crossovers are a class of electronic filter used in audio applications. Most individual loudspeaker drivers are incapable of covering the entire audio spectrum from low… …
83Medical ultrasonography — This article is about using ultrasound to image the human body. For imaging of animals in research, see Preclinical imaging. Sonography redirects here. For the tactile alphabet called sonography , see Night writing. Medical ultrasonography… …
84Modelocking — Mode locking is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, on the order of picoseconds (10 12s) or femtoseconds (10 15s).The basis of the technique is to induce a fixed phase… …
85Microwave transmission — The atmospheric attenuation of microwaves in dry air with a precipitable water vapor level of 0.001 mm. The downward spikes in the graph correspond to frequencies at which microwaves are absorbed more strongly, such as by oxygen molecules… …
86Dual-tone multi-frequency signaling — One of the few production telephone DTMF keypads with all 16 keys, from an Autovon Telephone. The column of red keys produces the A, B, C, and D DTMF events. Dual tone multi frequency signaling (DTMF) is used for telecommunication signaling over… …
87Mathematics of radio engineering — A complex valued function. The mathematics of radio engineering is a pleasant and very useful subject. This article is an attempt to provide a reasonably comprehensive summary of this almost limitless topic. While the ideas have historically… …
88Photonic metamaterial — Electromagnetism Electricity · …
89Microwave — This article is about the electromagnetic wave. For the cooking appliance, see Microwave oven. For other uses, see Microwaves (disambiguation). A microwave telecommunications tower on Wrights Hill in Wellington, New Zealand Microwaves, a subset… …
90Refractive index — Refraction of light at the interface between two media. In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum… …
