AMPLIFIERS, MULTI-STAGE.--A receiving set using two or more amplifiers. Also called cascade amplification.
AMPLIFIER, VACUUM TUBE.--A vacuum tube that is used either to amplify the radio frequency currents or the audio frequency currents.
AMPLITUDE OF WAVE.--The greatest distance that a point moves from its position of rest.
AMPLIFYING TRANSFORMER, AUDIO.--See Transformer, Audio Amplifying.
AMPLIFYING MODULATOR VACUUM TUBE.--See Vacuum Tube, Amplifying Modulator.
AMPLIFYING TRANSFORMER RADIO.--See Transformer, Radio Amplifying.
ANTENNA, AMATEUR.--See Aerial, Amateur.
ANTENNA SWITCH.--See Switch, Aerial.
APPARATUS SYMBOLS.--See Symbols, Apparatus.
ARMSTRONG CIRCUIT.--See Circuit, Armstrong.