(amp)- Ampere                
AC/DC-
Alternating current or direct current            

ADC -Analog-to-digital converter

AF-Audio frequency

AFC -Automatic flow controller, used in controlling the flow of gasses under pressure into a vacuum system

AFC -Automatic frequency control

AFT -Automatic fine tuning                  

AGC-Automatic gain control      

Ah -Ampere hour

Ai -Current gain
c -Centi (10-2)

AM/FM -Amplitude modulation or Frequency modulation   
AMM
-Analog multimeter

AM-Amplitude modulation

antilog – Antilogarithm

Ap -Power gain
Apc-
Automatic phase control
Av -Voltage gain
AVC
-Automatic volume control  
AWG
-American wire gauge
AC- Alternating current
A/D-
Analog to digital

bfo -Beat frequency oscillator
BJT -Bipolar junction transistor

BW-Bandwidth
d-
Deci (10-1)

C -Capacitance or capacitor       
CAD
-Computer aided design

CAM -Computer aided manufacture    
CATV
-Cable TV

CB -Common base configuration
CB-
Citizen's band

CC -Common collector                
CE-
Common emitter
cm
–Centimeter                          
cmil
-Circular mil

CPU- Central processing unit      
C (Q)-
Coulomb

CR cr -Junction diode                 
CRO-
Cathode ray Oscilloscope
CRT -Cathode ray tube               
CT -
Total capacitance
cw
-Continuous transmission
E DC- or Erms Difference in potential

D/A or D-A-Digital to analog    
DC-
Direct current
DIP-
Dual in-line package            
DMM
-Digital multimeter

DPDT -Double pole double throw
DTL-
Diode transistor logic
DVM-
Digital voltmeter
 – Frequency
FET-Field effect transistor

e -Instantaneous difference in potential 
ECG-
Electrocardiogram

ECL -Emitter coupled logic         
EHF-
Extremely high frequency

EHV- Extra high voltage              
ELF- Extremely low frequency

EMF-Electromotive force            
EMI-
Electromagnetic interference
EW-
Electronic warfare

FF-Flip Flop    
fil
–Filament

FM- Frequncy modulation    
f
r
-Frequency at resonance
fsk
-frequency-shift keying   
FSD-
Full scale deflection
H-
Henry
H-
Magnetic field intensity
H
-Magnetizing flux
h-
hecto (102 )
h -Hybrid
HF-
High frequency
hp -Horsepower
Hz
-Hertz
I
-Current
i -Instantaneous current
IB -DC Base current
IC -
DC Collector current
IC- Integrated circuit
Ie-
Total emitter current
Ieff- Effective current
IF-
Intermediate frequency
I
max -
Maximum current
I
min -
Minimum current
I/O-
Input/output
IR- Infrared
IR-
Resistor current
IS -
Secondary current
I
T -
Total current
K-
Coefficient of coupling
k-
Kilo (103 )
kHz-
Kilohertz
kV- Kilovolt
kVA-
Kilovoltampere
kW-
Kilowatt
kWh-
Kilowatt-hour
M
-Mega (106 )
M
-Mutual conductance
MI
-Mutual inductance
m-
Milli (10-3 )
mA-
Milliampere
mag-
Magnetron
max –Maximum
MF- Medium frequency
MH-
Millihenry
G-
Gravitational force
G
-Conductance
G-
Giga (109 )
JFET-
Junction field effedt transistor
L-
Coil, inductance
LC-
Inductance-capacitance
LCD-
Liquid crystal display
L-C-R
-Inductance-capacitance-resistance
LDR-
Light-dependent resistor
LED-
Light emitting diode
LF-
Low frequency
LM-
Mutual inductance
LNA-
Low noise amplifier
LO
-Local oscillator
LSI-
Large scale integration
LT -
Total inductance
N
-Number of turns in an inductor
N-
Revolutions per minute
n-
Nano (10-9)
N-
Negative
NA-
Nanoampere
NC-
Normally closed
NC
No- connection
NEG, neg –Negative
NF
-Nanofarad
nH
-Nanohenry
nm-
Nanometer
NO-
Normally open
NPN-
Negative-positive-negative
Ns-
Nanosecond
NW-
Nanowatt

MHz -Megahertz
min
–Minimum
mm-
Millimeter
mmf -Magnetomotive force
mW-
Milliwatt
MOS
-Metal oxide semiconductor
MOSFET
-Metal oxide semiconductor field effect transistor
MPU-
Microprocessor unit
MSI-
Medium scale integrated circuit
mV
–Millivolt
P-
Pico (10-12)
P-
Power
p-
Instantaneous power
P-
Positive, also peak
PA-
Public address or power amplifier
PA-
Picoampere
PAL-
Programmable Array Logic
UJT-Unijunction transistor
UV-
Ultraviolet
V-
Vacuum tube
V, v-
Volt
v-
Instantaneous voltage
VA-
Volt ampere
Vav-
Voltage (average value)
VBE-
DC voltage base to emitter
Vc-
Capacitive voltage
VCE-
DC voltage collector to emitter
VCO-
Voltage controlled oscillator 
VHF-
Very high frequency
VIn -
Input voltage
VL- Inductive voltage
VLF-
Very low frequency
V
m, Vmax
-Maximum voltage
VOM-
Volt ohm milliameter
 Vout -Output voltage
V
p -
Primary voltage
VS-Source voltage
V
SWR-
Voltage standing wave ratio
V
T-
Total voltage

OP AMP- Operational amplifier
R-
Potentiometer
R-
Resistance
RAM-
Random access memory
RC-
Resistance-capacitance, also Radio controlled
Rcvr-
Receiver
Rect-
Rectifier
Ref-
Reference
Rf-
Radio frequencies
RF-
Radio frequencies
RFI-
Radio frequency interference
RL-
Load resistor
RLC-
Resistance-capacitance-inductance
RMS, rms- Root mean square
ROM-
Read only memory
Rpm-
Revolutions per minute
T-
Tera (1012)
T
-Torque
T
-Transformer
t-
Time in seconds
TC-
Time constant, also temperature coefficient
TE-
Transverse  electric
Temp-
Temperature

PAM, pam- Pulse amplitude modulation
Pap-
Apparent power
Pav-
Average power
PCB-
Printed circuit board
PCM, pcm-
Pulse-code modulation
PDM-
Pulse-duration modulation
PF-
Picofarad
PLD-
Programmable Logic Device
PLL-
Phase locked loop
PM-
Phase modulation, also Permanent magnet
PNP-
Positive-negative-positive
POT, pot-
Potentiometer
P-P-
Peak to peak
PPM--
Pulse-position modulation
PRF-
Pulse repetition frequency
PRT-
Pulse repetition time
Pw-
Pulse width
PWM, pwm-
Pulse width modulation
Q-Charge, also quality
q-Instantaneous charge
SCR-
Silicon controlled rectifier
SHF-Super high frequency
SIP-
Single in-line package
SNR-
Signal-to-noise ratio
SPDT-
Single pole double throw
sq cm-
Square centimeter
SSB-
Single sideband
SW-
Short wave
SWR-Standing-wave ratio
SYNC, sync-Synchronous
UHF- Ultra high frequency
UHV-
Ultra high voltage

THz-Terahertz
TM-
Transverse magnetic
TR-
Transmit-receive
TTL-
Transistor-transistor logic
TWT-
Travelling wave tube
TV - Television
W
–Watt
XC
-Capacitive reactance
XL
-Inductive reactance
Y
-Admittance
Z
–Impedance

Zin -Input impedance
Zo
-Output impedance
Zp
-Primary impedance
Zs
-Secondary impedance
ZT
-Total impedance
B
-Flux density
BCD -Binary coded decimal