ultrahigh frequencies

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• ultrahigh frequency — Frequencies of electromagnetic radiation between 300 and 3000 MHz, or of wavelengths between 100 and 10 cm. These frequencies are mainly used by military for air to air and air to ground voice communications on a line of sight basis. In some… …   Aviation dictionary

• ultrahigh — adj. extremely high (radio frequencies) …   English contemporary dictionary

• radio — /ray dee oh /, n., pl. radios, adj., v., radioed, radioing. n. 1. wireless telegraphy or telephony: speeches broadcast by radio. 2. an apparatus for receiving or transmitting radio broadcasts. 3. a message transmitted by radio. adj. 4. pertaining …   Universalium

• transistor — /tran zis teuhr/, n. 1. Electronics. a semiconductor device that amplifies, oscillates, or switches the flow of current between two terminals by varying the current or voltage between one of the terminals and a third: although much smaller in… …   Universalium

• Frequency band designations — ▪ Table Frequency band designations frequency designation frequency range wavelength range very low frequencies (vlf) 3–30 kilohertz 100,000–10,000 m low frequencies (lf) 30–300 kilohertz 10,000–1,000 m medium frequencies (mf) 300–3,000 kilohertz …   Universalium

• warning system — ▪ military technology Introduction       in military science, any method used to detect the situation or intention of an enemy so that warning can be given.       Because military tactics from time immemorial have stressed the value of surprise… …   Universalium

• nondirectional beacon — A radio navigational aid that enables the pilot to obtain his bearing from a transmitting station. A transmitter operating in long or medium wave frequencies, or even in UHFs (ultrahigh frequencies), with the code of the station superimposed on… …   Aviation dictionary

• Barkhausen, Heinrich Georg — ▪ German physicist born Dec. 2, 1881, Bremen, Ger. died Feb. 20, 1956, Dresden, E.Ger. [Germany]       German physicist who discovered the Barkhausen effect, a principle concerning changes in the magnetic properties of metal.       Barkhausen… …   Universalium

• J-antenna — A half wave antenna, end fed by a parallel wire quarter wave section having the configuration of a “J.” The antenna has an omnidirectional radiation pattern in the horizontal plane. This antenna is used primarily at very high and ultrahigh… …   Aviation dictionary

• traveling-wave tube — noun : an electron tube used for the generation of microwave frequency radiation or for amplification at ultrahigh frequencies whose operation depends on the interaction of a beam of electrons with an electromagnetic wave * * * /trav euh ling… …   Useful english dictionary

• ultrahighfrequency — ultrahigh frequency n. Abbr. UHF A band of radio frequencies from 300 to 3,000 megahertz. * * * …   Universalium