Tektronix 1740A/1750A Making Waveform Measurements, Peak White, K-FactorMeasurements, Horizontal Sync Amplitude

Basic Measurements

Making Waveform Measurements

Horizontal Sync Amplitude

The vertical scale at sync tip (40 IRE NTSC or -0.3 V PAL) provides ±2 and ±4 IRE (±2 and ±4 mV) for measuring sync amplitude. Align the blanking level of a centered two-line waveform display on the graticule baseline to place the sync pulse directly over this structure. Measure sync amplitude directly from the graticule, or use the voltage cursors.

Peak White

With the blanking signal level on the graticule baseline, the amplitude of the 100% white reference of a color bar should be on the 100 IRE (1 V) graticule line. With a 2 LINE sweep rate, use the HORIZ POS control to place the white reference directly over the amplitude scale at graticule center. The vertical markings there correspond to 2 IRE/division (10 mV/ division for PAL). Measure peak white directly from the graticule or use the voltage cursors.

K-Factor Measurements

The boxed area in the upper left corner of the graticule is scaled for 2% and 4% K-Factor ratings for precise tilt mea- surements. This structure is designed to work with an 8 µs half-amplitude duration (HAD) bar. The bar tilt measurement structure can also be used to measure pulse-to-bar ratio. Calibrated X5 GAIN can be used while making these measure- ments; it increases resolution to 0.4% and 0.8%.

To use the NTSC vertical scale to make line-time distortion and pulse-to-bar ratio measurements, position the signal blanking level to the graticule baseline. Next, position the center of the composite test signal bar to the center of the 2T bar measurement box and check to see if insertion gain is unity. If it is not, adjust the VARIABLE GAIN (enabled from the GAIN MENU) for exactly 100 IRE (700 mV PAL) of signal amplitude from baseline to the middle of the white bar.

1740A/1750A Series Waveform/Vector Monitor User Manual 4-5