| AES/EBU - |
Audio Engineering Society/European Broadcast Union, both standard-setting
organizations. Also a shortened reference to a particular standard for digital
audio information transfer, such as AES3, AES5, AES18, or AES41 |
| AM - |
Amplitude modulation |
| Analog STL - |
A general reference to any studio-transmitter-link which employs FM modulation
of the baseband onto the carrier whether or not components in the baseband
carry analog or digital information |
| Antenna - |
A device, which radiates or captures RF energy. |
| Antenna Gain - |
The gain of a particular antenna referred to a standard antenna such as
a dipole or isotropic radiator. |
| ASCII - |
A code for exchange of information, American Standard Code for Information
Interchange |
| Attenuator - |
A device that reduces the amplitude of an electrical signal. |
| Aural - |
Pertaining to the ear (hearing) |
| Aural STL - |
A general reference to any studio-transmitter-link that conveys the audio
portion of a broadcast as opposed to the video (if any) portion of a broadcast. |
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| Bandpass - |
The characteristics of a device or system to allow certain frequencies
to pass with less attenuation than other frequencies |
| Bandpass filter - |
A device which allows certain frequencies to pass with less attenuation
than other frequencies |
| Bandwidth - |
The range of frequencies allowed to pass through a device or system with
less attenuation than other frequencies |
| Baud - |
A unit of speed in data transmission, such as one bit per second for binary
signals |
| Bessel Null Calibration - |
A method of determining the deviation of a frequency modulated signal
by observing a detector for the apparent disappearance of the carrier in
accordance with relationships described by a series of mathematical functions
first described by Polish astronomer Frederick Bessel. |
| BPSK - |
Bi-Phase Shift Keying, a method of modulating a signal to transfer information |
| BTSC - |
Broadcast Television Standards Committee |
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| Carrier - |
The fundamental radio frequency of an electrical signal whether it is
modulated or not |
| Carrier shift - |
The change in carrier amplitude due to modulation |
| CCIR - |
International Radio Consultative Committee |
| Changeover - |
A device used in hot stand-by STL applications to transfer operation from
a primary (transmitter or receiver) device to a back-up device |
| Channel - |
The band or designation of a range of frequencies allocated for a specific
purpose |
| Channel Spacing - |
The arithmetic difference between the carriers in a specific band arrangement |
| CNR - |
Carrier-to-Noise Ratio, generally the amplitude difference between an
RF carrier and the noise floor expressed in dBc |
| Coax - |
Shortened term for “coaxial”, usually applied to a type of
transmission line in which current carrying conductors are arranged with
the same centers but with differing radii |
| Co-channel interference - |
Characteristic of two RF signals on the same carrier or band of frequencies |
| Composite (MPX) - |
Reference to the combined signals on particular baseband that is usually
modulated or demodulated. For FM broadcast signals it generally consists
of L+R, L-R (dual sideband, suppressed carrier), pilot, and other SCAs and/or
subcarriers. For STL signals it generally refers to all signals presented
to the modulator or demodulated from the discriminator. |
| Crosstalk - |
The amplitude relationship of two signals in a system |
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| DAB - |
Digital Audio Broadcasting |
| Data Channel - |
An information channel which transports data, usually for remote control
or supervisory purposes or sometimes broadcast for public reception |
| dB - |
Abbreviation for decibel, one-tenth of a Bel, a logarithmic ratio |
| dBc - |
Ratio of the amplitudes of a particular signal to a carrier |
| dBd - |
Gain of an antenna compared to a standard dipole radiator |
| dBi - |
Gain of an antenna compared to a standard isotropic radiator |
| dBm - |
Ratio of the power of a signal to 1 milliwatt |
| Decoder - |
A device to transfer a signal from one mode to another |
| Deviation - |
In frequency modulation, the instantaneous excursion of the carrier frequency
due to modulation |
| Digital Decoder - |
A device to transfer a digital signal to some other mode, usually analog |
| Digital Encoder - |
A device to transfer a signal, usually analog, to some digital form |
| Digital Rx - |
A receiver of a digitally modulated signal |
| Digital STL - |
A studio-transmitter-link that employs digital modulation techniques of
the carrier |
| Digital Tx - |
A transmitter and modulator of a digital signal |
| Dipole Antenna - |
An antenna with length near a half wavelength |
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|
| EAS - |
Emergency Alert System |
| EAS protocol - |
The signal and order required by 47 C.F.R. Part 11 for transmission of
EAS messages. |
| Emission designator - |
The classification of signals by designations for types of modulation
of the main carrier, the nature of the signals modulating the main carrier,
and the type of information transmitted |
| Encoder - |
A device to transfer a signal from one mode to another that is opposite
from that of a decoder |
| Encoder/decoder - |
A device which combines the characteristics of both an encoder and decoder |
| EOM - |
End-of-Message, a component of the EAS protocol that signifies the end
of an EAS message and resets various components |
| EIRP - |
Effective Incidental Radiated Power |
| ERP - |
Effective Radiated Power |
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| Fade Margin - |
The ratio, general expressed in dB, of a received signal to the threshold
of successful demodulation in a particular receiver |
| FIPS - |
Federal Information Processing System, a Department of Commerce assigned
number that designates a geographic area of the United States and its territorial
possessions |
| FM - |
Frequency modulation |
| Forwarding - |
The process of analyzing an incoming EAS message to an EAS 911 encoder/decoder
to check for validity and then to retransmit the same message |
| Frequency agile - |
Having the ability of changing frequency |
| Frequency response - |
The band of frequencies passed by a given component or system with little
attenuation |
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| GHz - |
Abbreviation for gigahertz |
| Group delay - |
The variation in time of different frequencies through a given system |
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| Hardwire bypass - |
A method of equipment connection by which the input is directly connected
to the output in the event of equipment or power failure in order to bypass
the equipment |
| HD - |
High Definition |
| Heterodyne - |
To combine two different radio frequencies so as to produce the sum and
difference of the two frequencies |
| HRC - |
Harmonically Related Carriers, generally a technique in cable television
systems in which the individual visual and aural carriers are related by
a specific multiple by using coherent oscillators |
| Hz - |
Hertz, cycles per second |
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| IBOC - |
In Band On Channel a method of transmitting both digital and analog carriers
and information on the same frequency for FM broadcasting |
| IF - |
Intermediate Frequency |
| Intercarrier - |
The difference between the visual and aural carriers in an NTSC system,
fixed at 4.5 MHz |
| IRC - |
Independently Related Carriers, the opposite of HRC |
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| kHz - |
kilohertz, one thousand cycles per second |
| ks/s - |
kilo-samples per second |
| kW - |
kilowatt(s), one thousand Watts |
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| LCD - |
Liquid crystal display |
| LED - |
Light emitting diode |
| Linear Channel - |
A channel with fairly even frequency response. Also “not compressed”,
when applied to digital transmissions |
| LPFM - |
Low Power Frequency Modulation, a service for FM broadcast with low power
transmitters |
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|
| MHz - |
Megahertz, one million cycles per second |
| Modem - |
Modulator/demodulator |
| Multipath - |
A phenomenon in which signals arrive at a receiver by at least two different
paths, one of which may be reflected |
| Multiplexer - |
A device which combines individual signals into a composite signal |
| MW - |
Medium-wave, generally consider to be the band of frequencies between
300 kHz and 3 MHz |
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|
| NOAA - |
National Oceanographic and Atmospheric Administration, a division of the
Department of Commerce |
| NRSC - |
National Radio Systems Committee, a standards setting body concerned with
radio broadcasting in the United States |
| NTSC - |
National Television Standards Commission, the standard setting body and
system of analog color broadcasting used in the United States |
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| Occupied bandwidth - |
The band of frequencies occupied by an RF carrier and its modulation components,
if any |
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| P.M.D.D. - |
Pulse Modulation Duration Differentiator, a technique employed in TFT
modulation monitors to discriminate between short and long peaks in a received
FM modulated signal for the purposes of distinguishing true over modulation
from peaks that result from multipath |
| Path - |
The route traveled by an RF signal from its source to its receiver |
| Path Reliability - |
The statistical measurement of reliability of an RF path based upon a
90,10 property, in which signal will be available at 90% of the locations
measured at least 10% of the time |
| Pilot - |
signal used to develop other signals in a receiver, such as a 19 kHz
pilot is used for multiple purposes in a stereo FM receiver |
| Polarization - |
The dimensional aspect(s) of an electromagnetic wave, e.g. linear, circular,
elliptical, represented by two complex numbers |
| Pre-/de-emphasis - |
The dimensional aspect(s) of an electromagnetic wave, e.g. linear, circular,
elliptical, represented by two complex numbers |
| Pro - |
In a BTSC analog television signal, the narrowband subcarrier which is
6.5 times the horizontal scanning frequency and usually conveys cues and
orders or data on a closed circuit basis, not to the general public |
| Program Channel - |
The primary channel of program information usually intended for ultimate
transmission to the public |
| Proof-of-Performance - |
A series of measurements required by the FCC to insure compliance with
certain transmission parameters of a licensed facility |
| Propagation - |
The movement of a radio frequency wave through a medium |
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|
| QAM - |
Quadrature Amplitude Modulation |
| QPSK - |
Quadrature Phase Shift Keying (modulation) |
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| Radio Frequency - |
An electromagnetic wave capable of being transmitted and received through
space |
| Radio Link - |
A system for transmitting information between two points by means of an
electromagnetic wave |
| RDS/RBDS - |
Radio Data System (European)/Radio Broadcast Data System (US) |
| RF Gain - |
The addition or loss in an RF system caused by a particular device, either
active or passive, and usually measured in dB |
| RMS - |
Root-Mean-Square, the square root of the mean of a set of numbers, usually
instantaneous Voltages |
| RSSI - |
Received Signal Strength Indication, usually expressed in microvolts or
millivolts |
| RS-232 - |
A physical electrical interface standard established by the Electronic
Industries Association (EIA) |
| RS-422 - |
A physical electrical interface standard established by the Electronic
Industries Association (EIA) |
| RS-485 - |
A physical electrical interface standard established by the Electronic
Industries Association (EIA) |
| Rx (Receiver) - |
A device used to recover and demodulate an RF wave |
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|
| S.A.M.E. protocol - |
Specific Area Message Encoding, a protocol used by NOAA Weather Radio,
similar to EAS protocol |
| Sample Rate - |
In digital modulation, the rate at which a particular signal is sampled
and digitized |
| SAP - |
Secondary Audio Program, in BTSC analog television broadcasting, the signal
that is on a subcarrier that is 5 times the frequency of the horizontal
synchronizing frequency |
| SCA - |
Store Casting Authority, term applied to subcarriers in an FM broadcast
composite signal that lie between the upper limit of the main program information
and 100 kHz - |
| SNR - |
Signal-to-Noise ratio, expressed either in dB or percent |
| Splitter - |
A device used to divide an RF signal into two different paths, also sometimes
called a power divider |
| Squelch - |
A circuit used to quiet the output of a receiver when the RF input falls
below a pre-determined level |
| Step Size - |
The tuning increment between RF carriers |
| Stereo Channel Separation - |
The ratio in dB between LEFT or RIGHT signals in a stereo system and the
noise in the opposite channel |
| Stereo Generator - |
The ratio in dB between LEFT or RIGHT signals in a stereo system and the
noise in the opposite channel |
| STL - |
Studio-to-Transmitter-Link, the radio system that conveys programming
material from a studio to a transmitter site |
| Subcarrier - |
A signal which carries information imposed on a baseband and presented
to a modulator |
|
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| THD - |
Total Harmonic Distortion |
| Tx (Transmitter) - |
A device used to generate an RF signal capable of being received at some
distance |
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| UHF - |
Ultra High Frequency, frequency between 300 and 3,000 MHz |
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| V.35 - |
A physical interface standard promulgated by the International Telegraph
and Telephone Consultative Committee (CCITT) |
| VHF - |
Very High Frequency, frequency between 30 and 300 MHz |
| Visual - |
Pertaining to the portion of a television signal which conveys video information |
| VSWR - |
Voltage Standing Wave Ratio, the ratio of maximum voltage along a transmission
line to the minimum voltage expressed with the numerator greater than 1 |
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| Watt - |
Unit of power, one joule per second |
| Wavelength - |
The distance between two points of corresponding phase in consecutive
cycles, commonly designated by the small Greek letter lamda |
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| Yagi - |
A type of antenna with a single driven element and one or more parasitic
reflectors in back or in front of the driven element |
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