Campbell Scientific RF320-Series Ritron VHF/UHF Radios - Manual (Page 29)

Appendix A. Glossary
Antenna: That part of a radio communications system intended to radiate
and/or collect radio frequency energy.
Antenna Gain: A relative measure of an antenna’s ability to direct or
concentrate radio frequency energy in a particular direction or pattern.
Typically measured in dBi or dBd.
Attenuation: The loss or weakening of a signal through a transmission line,
transmission component, or signal path. Usually refers to loss in signal
amplitude or signal power, and is typically measured in decibels (dB).
Attenuator: A component that reduces the magnitude of current, voltage, or
power of a signal in transmission between points. The input and output
impedance of the attenuator normally matches the system.
Base Station: A focal point in the network for data collection and
communications. One base station can service one or more remote sites.
Bit Error Rate (BER): The number of bit errors in a data stream divided by
the number of bits transmitted over a given interval.
Coaxial Cable, Coax: A concentric two-conductor cable in which one
conductor surrounds the other, separated by an insulator or dielectric.
Continuous Tone Coded Squelch System (CTCSS): A system whereby one
of 38 selectable tone codes in the range of 67 to 250 Hz is transmitted in the
modulated carrier wave for the purpose of selectively squelching the received
signal. (See also Tone Squelch and DCS.)
dBd: A unit of measure for expressing antenna gain relative to a half-wave
dipole. (See also Decibel and Dipole) dBd = dBi – 2.15
dBi : A unit of measure for expressing antenna gain relative to an isotrope.
(See also Decibel and Isotrope) dBi = dBd + 2.15
dBm: A unit of measure for expressing Power relative to one milliwatt. (See
also Decibel)
dBW: A unit of measure for expressing Power relative to one Watt. (See also
Decibel)
Digital Coded Squelch (DCS): Similar in purpose to CTCSS, but in place of a
continuous audio tone, a numerically-encoded, low-rate bit stream is
transmitted in the modulated carrier wave. (See also CTCSS and Tone
Squelch.)
Decibel ( dB ): A logarithmic representation of magnitude relationships
commonly used in radio and sound measurement. A Decibel is 1/10 of a Bel.
Demodulate: The process of extracting information in the form of audio or
data (binary bit stream) from the received RF signal.
A-1