Tektronix 1740A/1750A - Manual (Page 137)

Glossary
G-8
1740A/1750A Series Waveform/Vector Monitor User Manual
Subcarrier The modulation sidebands of the color subcar-
rier contain the R--Y (V) and B--Y (U) information. For
NTSC, subcarrier frequency is 3.579545 MHz.
For PAL,
subcarrier frequency is 4,433,618.75 Hz.
Synchronous Detection A demodulation process in
which the original signal is recovered by multiplying the
modulated signal with the output of a synchronous oscillator
locked to the carrier.
Termination In order to accurately send a signal through
a transmission line, there must be an impedance at the end
which matches the impedance of the source and of the line
itself. Amplitude errors and reflections will otherwise result.
Video is a 75
Ω system, so a 75 Ω terminator must be put at
the end of the signal path.
Time Code, Longitudinal (LTC) LTC is an 80-bit
signal with information which makes it possible to accurately
identify an individual frame. The LTC signal is typically
recorded on an audio channel.
Time Code, Vertical (VITC) VITC is a signal in the
vertical interval of video, which makes it possible to accu-
rately identify an individual field.
U The B--Y signal after a weighting factor of 0.493 has been
applied. The weighting is necessary to reduce peak modula-
tion in the composite signal.
Unmodulated When used to describe television test
signals, this term refers to pulses and pedestals which do not
have high--frequency chrominance information added to
them.
V The R--Y signal after a weighting factor of 0.877 has been
applied. The weighting is necessary to reduce peak modula-
tion in the composite signal.
Vectorscope A specialized oscilloscope which demodu-
lates the video signal and presents a display of R--Y versus
B--Y in NTSC systems (or V versus U in PAL systems). The
angle and magnitude of the displayed vectors are respectively
related to hue and saturation.