AMMETER, RADIO.--See Ammeter, Hot Wire.
AMPERE.--The current which when passed through a solution of nitrate of silver in water according to certain specifications, deposits silver at the rate of 0.00111800 of a gram per second.
AMPERE-HOUR.--The quantity of electricity transferred by a current of 1 ampere in 1 hour and is, therefore, equal to 3600 coulombs.
AMPERE-TURNS.--When a coil is wound up with a number of turns of wire and a current is made to flow through it, it behaves like a magnet. B The strength of the magnetic field inside of the coil depends on (1) the strength of the current and (2) the number of turns of wire on the coil. Thus a feeble current flowing through a large number of turns will produce as strong a magnetic field as a strong current flowing through a few turns of wire. This product of the current in amperes times the number of turns of wire on the coil is called the ampere-turns.
AMPLIFICATION, AUDIO FREQUENCY.--A current of audio frequency that is amplified by an amplifier tube or other means.
AMPLIFICATION, CASCADE.--See Cascade Amplification.
AMPLIFICATION, RADIO FREQUENCY.--A current of radio frequency that is amplified by an amplifier tube or other means before it reaches the detector.
AMPLIFICATION, REGENERATIVE.--A scheme that uses a third circuit to feed back part of the oscillations through a vacuum tube and which increases its sensitiveness when used as a detector and multiplies its action as an amplifier and an oscillator.
AMPLIFIER, AUDIO FREQUENCY.--A vacuum tube or other device that amplifies the signals after passing through the detector.
AMPLIFIER, MAGNETIC.--A device used for controlling radio frequency currents either by means of a telegraph key or a microphone transmitter. The controlling current flows through a separate circuit from that of the radio current and a fraction of an ampere will control several amperes in the aerial wire.