Many abbreviations are found as either capital or lower case letters, depending on publishers’ styles. Symbols should generally be standard, 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 Auxiliary
a.v.c. Automatic volume control
AWG American Wine Gauge
b Base of transistor
BAF Bonded acetate fibre
B & S Brown & Sharpe (U.S.) wire gauge
b.p.s. Bits per second
BR Bass reflex
BSI British Standards Institution
BW Bandwidth
C Capacitor, cathode, centigrade, coulomb c Collector of transistor, speed of light
CB Citizen’s band
CCD Charge coupled device
CCIR International Radio Consultative Committee
Consultative Committee
CCTV Closed circuit television
CDMA Code division multiple access
chps Characters per second
CISPR Comit´e International Special Des Peturbations
(radio interference standards body) CLK Clock signal
CMOS Complementary metal oxide semiconductor CrO2 Chromium dioxide
CPU Central processor unit
CTCSS Continuous tone controlled signalled system CTD Charge transfer device
c.w. Continuous wave
D Diode
d Drain of an f.e.t.
D/A Digital to analogue
DAC Digital to analogue converter
dB Decibel
d.c. Direct current
DCC Double cotton covered
DCE Data circuit-terminating equipment DCS Digital Communications Service
DF Direction finding
DIL Dual-in-line
DIN German standards institute
DMA Direct memory access
DPDT Double pole, double throw
DPSK Differential phase shift keying
DPST Double pole, single throw
dsb or dsbam. Double sideband amplitude
modulation
DSRR Digital short range radio
DTE Data terminal equipment
DTL Diode-transistor logic
DTMF Dual tone multi-frequency
DX Long distance reception
e Emitter of transistor
EAROM Electrically alterable read only memory ECL Emitter coupled logic
EDGE Enhanced Data for GSM Evolution e.h.t. Extremely high tension (voltage)
EIRP Effective Isotropic Radiated Power e.m.f. Electromotive force
en Enamelled
EPROM Erasable programmable read only memory EQ Equalization
EROM Erasable read only memory
ERP Effective radiated power
ETACS Extended total access communications system F Farad, fahrenheit or force
f Frequency
FDD Frequency Division Duplex
FDM Frequency division multiplex
FDMA Frequency division multiple access Fe Ferrous
FeCr Ferri-chrome
f.e.t. Field effect transistor
FFSK Fast frequency shift keying
f.m. Frequency modulation
f.r. Frequency response or range
f.s.d. Full-scale deflection
FSK Frequency shift keying
G Giga (109)
g Grid, gravitational constant
GMSK Gaussian minimum shift keying
GSM Global system mobile
H Henry
h.f. High frequency
Hz Hertz (cycles per second)
I Current
IB Infinite baffle
i.c. Integrated circuit
IF Intermediate frequency
IHF Institute of High Fidelity (U.S.)
I2L(HL) Integrated injection logic
i.m.d. Intermodulation distortion
i/p Input
i.p.s. Inches per second
K Kilo, in computing terms (= 210 = 1024),or
degrees Kelvin
k Kilo (103) or cathode
L Inductance or lumens
l.e.d. Light emitting diode
l.f. Low frequency
LIN Linear
LOG Logarithmic
LS Loudspeaker
LSI Large scale integration
l.w. Long wave (approx. 1100–2000 m) MMega (106)
m Milli (10−3) or metres
m.c. Moving coil
MHz Megahertz
mic Microphone
MOS Metal oxide semiconductor
MPU Microprocessor unit
MPX Multiplex
MSC Mobile Switching Centre
MSK Minimum shift keying
m.w. Medium wave (approx. 185–560 m) n Nano (109)
NAB National Association of Broadcasters Ni-Cad Nickel-cadmium
n/c Not connected; normally closed
n/o Normally open
NMOS Negative channel metal oxide semiconductor NRZ Non-return to zero
o/c Open channel; open circuit
o/p Output
op-amp Operational amplifier
p Pico (10−12)
PA Public address
PABX Private automatic branch exchange PAL Phase alternation, line
p.a.m. Pulse amplitude modulation
PCB Printed circuit board
PCM Pulse code modulation
PCN Personal communications network PCS Personal communication system
PLA Programmable logic array
PLL Phase locked loop
pm Phase modulation
PMOS Positive channel metal oxide semiconductor P.P.M. Peak programme meter
p.r.f. Pulse repetition frequency
PROM Programmable read only memory
PSK Phase shift keying
PSS Packet SwitchStream
PSTN Public Switched Telephone Network PSU Power supply unit
PTFE Polytetrafluoroethylene
PU Pickup
PUJT Programmable unijunction transistor Q Quality factor; efficiency of tuned circuit, charge QAM Quadrature (or quaternary) amplitude
modulation
QPSK Quadrature (or quaternary) phase shift keying R Resistance
RAM Random access memory
RCF Recommended crossover frequency
r.f. Radio frequency
r.f.c. Radio frequency choke (coil)
RFI Radio frequency interference
RIAA Record Industry Association of America r.m.s. Root mean square
ROM Read only memory
RTL Resistor transistor logic
R/W Read/write
RX Receiver
S Siemens
s Source of an f.e.t.
s/c Short circuit
SCR Silicon-controlled rectifier
s.h.f. Super high frequency
SI International system of units
S/N Signal-to-noise.
SPL Sound pressure level
SPDT Single pole, double throw
SPST Single pole, single throw
ssb Single sideband amplitude modulation ssbdc Single sideband diminished carrier
ssbsc Single sideband suppressed carrier
SSI Small scale integration
s.w. Short wave (approx. 10–60 m)
s.w.g. Standard wire gauge
s.w.r. Standing wave ratio
TTesla
TACS Total access communications system TDD Time division duplex
TDM Time division multiplex
TDMA Time division multiple access
t.h.d. Total harmonic distortion
t.i.d. Transient intermodulation distortion TR Transformer
t.r.f. Tuned radio frequency
TRS Transmitter repeater station
TTL Transistor transistor logic
TTY Teletype unit
TVI Television interface; television interference TX Transmitter
UART Universal asynchronous receiver transmitter u.h.f. Ultra high frequency (approx. 470–854 MHz) u.j.t. Unijunction transistor
ULA Uncommitted logic array
V Volts
VA Volt-amps
v.c.a. Voltage controlled amplifier
v.c.o. Voltage controlled oscillator
VCT Voltage to current transactor
v.h.f. Very high frequency (approx. 88–216 MHz) v.l.f. Very low frequency
VSB Vestigial side band
VSWR Voltage standing wave ratio
VU Volume unit
W Watts
WAP Wireless application protocol
Wb Weber
W/F Wow and flutter
WML Wireless mark-up language
w.p.m. Words per minute
X Reactance
Xtal Crystal
Z Impedance
ZD Zener diode