Tektronix 1760 Manuel d'utilisateur télécharger pdf (Page 109)

Basic Measurements

1760 Series Component Waveform/Vector Monitor User Manual

4-9

MakingVectorMeasurements

Chroma Bandwidth

The horizontal and vertical axes of the vector graticule con-

tain markings for c hecking chroma bandwidth. A subca rrier

frequency sine wave (whose amplitude places it on the outer

compass rose) is used as a reference. W hen 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 che ck 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.

2°

dφ

Figure 4-5. Differential gain and phase measurements.

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Tektronix 1760 Manuel d'utilisateur Page 109