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The output voltage from IC503, pin #2 is applied to
the base of driver Q401.
The vertical output amplifier Q404 and Q405 operates
Class B push-pull.
When scanning the upper half of
the screen, deflection yoke current flows through
+lOOV, Q404.
When scanning the lower half of the
scree~,
the yoke current reverses flow through
Q405.
A sawtooth waveform developed across R408 and R409
drives the T/B Pincushion Correction Circuit.
Transistors Q402 and Q403 composed a complementary
emitter-follower to supply slight de current to the
vertical deflection yoke to adjust centering the
raster by Vert. Centering control, VR404.
3.5.2
Horizontal Deflection Circuit
The horizontal deflection circuits consist of the
IC503,
(Contains the horizontal oscillator and phase
lock circuit), drive circuit and horizontal output
circuit and horizontal centering circuit located on
the PCB-DEFL.
The horizontal oscillator incorporates a phase lock
circuit which locks the frequency and phase of the
horizontal deflection current to the horizontal sync
pulses stripped from the video input.
The free-running
oscillator frequency is primarily determined by capa-
citors C510, C538 and resistors RSll, VR502.
Horizontal Hold control VR502 adjusts the free-running
frequency by varying the base bias voltage on pin
number 12 of IC503.
3-11
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