
25 Abbreviations and symbols
25.1 Abbreviations
Many abbreviations are found as either capital or lower case letters,
depending on publishers’ styles. Symbols should generally be stan-
dard, as shown.
A Ampere or anode
ABR Auxiliary bass radiator
a.c. Alternating current
Ack Acknowledgement
A/D Analogue to digital
ADC Analogue to digital converter
Ae Aerial
a.f. Audio frequency
a.f.c. Automatic frequency control
a.g.c. Automatic gain control
a.m. Amplitude modulation
AMPS Advanced mobile phone system
ANSI American National Standards Institute
ASA Acoustical Society of America
ASCII American Standard Code for Information
Interchange
a.t.u. Aerial tuning unit
AUX