Tektronix Webcam 070-8030-01 User Manual

Theory of Operation

1780R-Series Service Manual

Demodulated R-Y (V) and B-Y (U) is amplified and input to a switching circuit
controlled by the Master MPU acting on front-panel switch selections. When
Vector or SCH display is selected, the Demodulated R-Y (V) is input to the
Vertical Deflection Amplifier, and the Demodulated B-Y (U) is input to the
Horizontal Deflection Amplifier. R-Y (V) and B-Y (U) Amplifier output signals
are fed back to the Demodulator circuits as chrominance level references for
Center Dot Clamping. The output signal from the R-Y (V) Amplifier is the
source of the waveform monitor R-Y for the R-Y sweep display.

In addition to amplifying the demodulated signals to match the CRT deflection
needs, the Deflection Amplifiers convert the single-ended input to a differential
output and matches the deflection plate capacitance to improve display linearity.

Luminance from the waveform monitor is low-pass filtered and amplified to
provide the delay required to match the Chroma processing delay. Delayed and
amplified luminance is input to the Horizontal Deflection Amplifier to produce
the Chrominance/Luminance display.