Tektronix 1740A/1750A Manuel d'utilisateur télécharger pdf (Page 90)

Basic Measurements

1740A/1750A Series Waveform/Vector Monitor User Manual

4-9

MakingVectorMeasurements

Chroma Bandwidth

The horizontal and vertical axes of the vector graticule

contain markings for checking chroma bandwidth. A subcar-

rier frequency sine wave (whose amplitude places it on the

outer compass rose) is used as a reference. When the fre-

quency is changed, the diameter of the circle should reduce.

At a point equal to 70% 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 demodula-

tor output 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.

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - FAX 781.665.0780 - TestEquipmentDepot.com

1 2 ... 85 86 87 88 89 90 91 92 93 94 95 ... 142 143

Pas de commentaire

Tektronix 1740A/1750A Manuel d'utilisateur Page 90