Tiernan TDR7, Manual

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dB Decibel—A unit of measure of signal strength, usually the
relation between a transmitted signal and a standard signal source. An
increase of 3
dB results in a doubling of the signal strength. An increase
of 6 dB results in a quadrupling of the signal strength. Conversely, a
decrease of 3 dB and 6 dB results in a reduction in signal strength by
one half and three quarters, respectively.
Decode To convert a coded signal into its original form.
Demod Demodulation. See Demodulate.
Demodulate To retrieve an electrical signal from a carrier signal or
wave.
DS3 A commercial leased line that has the capacity to handle up to
44.763 Mbps of digital information.
dsec Deci–seconds—A measurement of time that is equal to 0.1
seconds. For example, 15dsec is equal to 1.5 seconds.
DTE Data Termination Equipment—A generic name for any device
that generates information to be transmitted to another device or over
a transmission system. For example, visual display units, computers,
and office workstations.
DVB Digital Video Broadcast—A set of standards providing the
specifications for transmission and reception of digitally processed
broadcasting signals.
E
Eb/No Eb =Energy per information bit; No =Noise energy per
Hertz—Signal energy with respect to noise, expressed in energy per
bit/noise in 1
Hz bandwidth.