Mitsubishi C-6919 Service Manual page 23

Emitter-folloer Q201 drives Balanced Modulator, IC201.
IC201 controls Green video signal amplitude by a
control voltage from Gain control, VR292 located on
the front panel.
output signal from IC201, pin #6 is supplied to the
emitter-follower Q202. Transistors Q203 amplifies
video signal approximately 20 dB.
Output signal from emitter-follower Q204 is applied
to the backporch clamp circuit composed of Q205, Q206
and Q292.
A positive backporch pulse from the clamp pulse
generator drives the gate of N-Channel FET, Q205.
Normally Q205 is non-conducting. During the backporch
time interval, Q205 is turned on by a positive pulse,
and provides base bias to emitter-fcllower Q206 to
maintain the backporch level at the constant de level.
Q292 supplies
clam~
level voltage and the voltage
can be adjusted by VR291.
Cascade output amplifier formed
by
Q209 and Q210 is
driven from the emitter-follower Q206.
Series and shunt peaking are provided by L201, L202
and damping resistor R2C2. The capacitor-resistor
networks in the emitter of Q209 formed
by
R2Cl, C220
and C221 provide high frequency peaking.
Emitter-follower composed of Q211 and Q212 drives the
cathode of the CRT, and to neglect the stray capacit-
ance between cathode and signal ground.
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