(cf folded-dipole
21Monopole antenna — Mast radiator monopole antenna used for broadcasting. AM radio station WARE, Warren, Massachusetts, USA. A monopole antenna is a class of radio antenna consisting of a straight rod shaped conductor, often mounted perpendicularly over some type of …
22NVIS — Le N.V.I.S. (Near Vertical Incidence Skywave), en Français: onde radio ionosphèrique à incidence quasi verticale, est un mode de propagation utilisé pour des radiocommunications locales et régionales dans la bande des moyennes fréquences et… …
23Loudspeaker — For other uses, see Loudspeaker (disambiguation). An inexpensive, low fidelity 3½ inch speaker, typically found in small radios …
24Loudspeaker enclosure — A loudspeaker enclosure is a cabinet designed to transmit sound to the listener via mounted loudspeaker drive units. The major role of the enclosure is to prevent the out of phase sound waves from the rear of the speaker from combining with the… …
25Coaxial antenna — A coaxial antenna (often known as a coaxial dipole) is a particular form of a half wave dipole antenna, most often employed as a vertically polarized omnidirectional antenna. Contents 1 History 2 Configuration 3 Bazooka Dipole coaxial antenna …
26HRS antenna — HRS type antennas are more or less the standard antenna used for long distance high power shortwave broadcasting (> 1000 km). Contents 1 History of HRS design 2 Nomenclature 3 A versatile antenna type …
27Air Motion Transformer — The Air Motion Transformer (AMT) is a loudspeaker mechanism, or audio transducer, invented by Dr. Oskar Heil. It operates on a different principle than both electrodynamic and electrostatic speaker drivers. The AMT moves air in an augmented, semi …
28Whip antenna — on car A whip antenna is an antenna consisting of a single straight flexible wire or rod, often mounted above some type of conducting surface called a ground plane.[1] The bottom end of the whip is connected to the radio receiver or transmitter.… …
29Alpha helix — A common motif in the secondary structure of proteins, the alpha helix (α helix) is a right handed coiled conformation, resembling a spring, in which every backbone N H group donates a hydrogen bond to the backbone C=O group of the amino acid… …
30Parabolic antenna — A parabolic satellite communications antenna at Erdfunkstelle Raisting, the biggest facility for satellite communication in the world, in Raisting, Bavaria, Germany. It has a Cassegrain type feed. A parabolic antenna is an antenna that uses a… …
