Sharp VC-G20SM Serviceanleitung Seite 19

Notes:
1. Previously set the tracking control in the center position,
and adjust the ATR signal waveform to maximum with X
value adjustment nut. Thereby the tape run rough ad-
justment is facilitated.
2. Especially the outlet side ATR signal waveform must
have higher flatness.
Figure 4-27.
2. Adjustment of A/C head height and azimuth
1 Perform the initial setting of A/C head position by the
method stated in "4-15 Replacement 3".
2 Connect the oscilloscope to the audio output termi-
nal.
3 Using the alignment tape in which 1 kHz linear audio
signal has been recorded, adjust the height screw so
as to get max audio output.
4 Using the alignment tape in which 6 kHz linear audio
signal has been recorded, adjust the azimuth screw
so as to get max audio output.
5 The adjustment of 3 and 4 twice or three times
repeat, and finally adjust 4.
Figure 4-28.
3. Tape run adjustment
1 Connect the oscilloscope to PB ATR signal output
test point, set oscilloscope sync to EXT, trigger-input
the PB CHROMA signal (head switching pulse).
2 Rough adjustment of X value
Tentatively fix A/C head arm screws 1 by the method
described in 4-15 "Replacement 3".
Playback the alignment tape (VROUBZFS) and
shortcircuit between TP801 and TP802. As a result
the auto-tracking is automatically cancelled, so that
the X value adjustment mode is set.
Move the A/C head with the X value adjustment gear
driver (JiGDRiVER-6) by the method shown in Fig-
ure 4-33, and adjust the A/C head so as to get the
maximum ATR signal waveform. (Note: When the A/
C head is adjusted, adjust so that the maximum ATR
signal waveform is obtained nearest the position of
initial setting made in 4-15.)
For X value adjustment
Adjust the X value, turning the gear-
type screwdriver.
19
VC-G20SM/G200SM
VC-G201SM/G401SM