Table of Contents
Advertisement
4.12.3
Automatic Beam Limiter (ABL) Circuit
a.
Apply composite video signal of lVp-p to the input
terminal.
Turn the Gain, Contrast and Brightness
control fully clockwise.
b.
Set the scale of the VTVM to measure lSV.
Connect the probe of a VTVM (Vacuum Tube Voltage
Meter) to Connector (MB) pin #1 on PCB-VIDEO.
c.
ABL control (VR601) on PCB-VIDEO is factory sealed.
d.
The voltage at Connector (MB) pin #1 should be
9V
=
0. SV on the VTVM.
4.12.4
Color Temperature
a.
Turn
the Gain control (VR292) and Brightness
control (VR691) fully counterclockwise.
b.
Adjust the Brightness control (VR691) to obtain a
dim (just visible) raster.
c.
Set the scale of the VTVM to measure lSOV.
Connect the probe of a VTVM to the collector of
Q210, Q240 and Q270 on ?CB-VIDEO.
Set voltages
to 130V by adjusting R,G,B-Bias controls (VR201,
VR231 and VR261), respectively.
Observe the raster color to determine which CRT
beams are not visible.
Adjust the R,B,G-Bias controls (VR201, VR231 and
VR261) as required to e0ualize the three beam
intensities resultir.a a white (color) raster of
9300 Kelvin.
4-:i.l
Advertisement
Table of Contents
