4-10. DYNAMIC BEAM FOCUS (DBF) circuit
(1) H-DBF
The parabolic wave of horizontal period is output from pin 9 of IC301 and then amplified by approx. 18
times by Q518 and Q519. It increases up to approx. 500Vp-p by T503 and synthesized with V-
parabolic wave and then added to the focus circuit of the FBT (flyback transformer).
CRT cathode waveform
(H period)
T504 (FBT) pin 13:
DBF horizontal element input
(2) V-DBF
The parabolic wave of vertical period is output from pin 12 of IC350 and then amplified by approx.
100 times by Q520. It is synthesized with H-parabolic wave.
CRT cathode waveform
(V period)
T504 (FBT) pin 13:
DBF waveform input
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