JVC 340 SC - Manual (Page 38)

Chapter 2—Functional Descriptions
2-26 Model 330. 340SC, and 370SC Service Manual
Figure 2-12 Horizontal Deflection Board Block Diagram
Vertical Oscillator
The function of the vertical oscillator is to lock to the vertical signal, /VFBST, sent by the
RTG, and produce a pulsed output, VERTDR, of the same frequency. The /VFBST signal
initially is sent to a Frequency to Voltage converter to provide a program voltage to the
oscillator. This presets the oscillator frequency so the oscillator then is able to lock to the
incoming vertical sync signal.