Sony SLV-SE620 - Linearity Adjustment (Guide Roller S, T Adjustment)

2-2-2 Linearity Adjustment
(Guide roller S, T adjustment)
1) Playback the alignment tape (KRV-51N2
(NTSC) /51P (PAL)) (SP mode, Mono Scope).
2) Observe the video envelope signal on an oscillo-
scope (triggered by the video switching pulse).
3) Make sure the video envelope waveform (at its
minimum) meets the specification shown in
Fig. 2-6.
If it does not, adjust as follows :
Note :
a=Maximum output of the video RF envelope.
b=Minimum output of the video RF envelope at the
entrance side. :
c=Minimum output of the video RF envelope at the
center point,
d=Maximum output of the video RF envelope at the
exit side.
4) If the section A in Fig. 2-7 does not meet the speci-
fication, adjust the guide roller S up or down.
5) If the section B in Fig. 2-7 does not meet the speci-
fication, adjust the guide roller T up or down.
6) Play back the alignment tape (SP mode, Mono Scope).
oe oe
d
| ee |
abcd
cbd/a 263%
Fig. 2-6 Envelope Waveform Adjustment
H'D SWITCHING
PULSE
ENVELOPE
>
Fig. 2-7 Adjustment Points
7) Connect an oscilloscope CH-1 to the Envelope and CH-2 to the H’D SW Pulse for triggering.
8) Turn the guide roller heads with a flat head (WW) driver to obtain a flat video RF envelope as shown in Fig. 2-8.
S HEIGHT T00 HIGH SHEGHT TOO LOW
GUIDE ROLLER S
IDEAL ENVELOPE
THEIGHT TOO HIGH
THEIGHT T00 LOW
GUIDE ROLLER T
Fig. 2-8 Guide Roller S, T Height Adjustment
—23—