Making vector measurements, Chroma bandwidth, Differential phase and gain – Tektronix 1760 User Manual
Page 109
Basic Measurements
1760 Series Component Waveform/Vector Monitor User Manual
4-9
Making Vector Measurements
Chroma Bandwidth
The horizontal and vertical axes of the vector graticule con-
tain markings for checking chroma bandwidth. A subcarrier
frequency sine wave (whose amplitude places it on the outer
compass rose) is used as a reference. When the frequency is
changed, the diameter of the circle should reduce. At a point
equal to 70.7% of full amplitude (--3 dB), there are gaps in
the horizontal and vertical axes. This calibration aid makes
it possible to check the --3 dB points of the demodulator out-
put amplifiers.
Differential Phase and Gain
Differential gain (dG) and differential phase (d
∅) measure-
ments use the graticule markings located at the outer edge of
the B--Y or U axis. See Figure 4-5.
10
o
2°
dφ
dφ
Figure 4-5.
Differential gain and phase measurements.