Filter
Top Products
Theory of Operation
WFM 90 and WFM 91 Service Manual
3–3
16
Input Board
Ref
Var
Gain
Ext
Ref
Audio
In
Video
In
Video
Out
Front
Panel
Keys
Part of
mP
Rasterizer
and
Graphics
Vert
Defl
Horiz
Defl
Instrument
Control
Bottom Board P/O Top Board
LCD Display
and Backlight
Backlight
Power
Supply
Board
RGB
P/O Top Board
Part of
mP
Timing
Subcarrier
Oscillator
Timing
Sel Vid
Backlight
Brightness
RGB
Sweep
Trig
Fuse
Fuse
DC In
11–18 VDC
Battery
Sync
Separator
Power Supply
and Battery
Charger
±8 VDC
+5 VDC
Vector
±8 VDC
+5 VDC
Control DAC
(16 analog
Outputs)
Audio
Headphone
NTSC (or PAL)
Decoder (Self
contained
subcarrier
regenerator)
Burst
Lock
Vectorscope
(Including Ø
shifter)
Clamp
Video
Out
RGB from
Rasterizer
and Graphics
Video In
LPF
B–Y
Fsc
R–Y
DSync
Display
Brightness
and View
Adjust
2
RGB
Figure 3–1: Simplified block diagram