Sharp VC-M23SM Servicehandbuch Seite 21

ADJUSTMENT OF TAPE DRIVE TRAIN -. ~
'
|
"2:
Remove the cassette housing control assembly. — .
16.)
. Check and adjust the video search rewind back tension. (See
page 16.)
. Set the A/C head. (See page 19.)
. Rough adjustment of tape drive train.
a) Connect the oscilloscope to the test point for PB CHROMA
envelope output (TP301). Set the synchronism
of the
oscilloscope to EXT. The PB CHROMA
signal is to be
triggered by the head switching pulse (TP302).
Guide roller
Cassette tape
"S
Hexagon wrench
Figure 4-30. Figure 4-31.
d) In the X value adjustment mode (see the Electrical Adjust-
ment), change the envelope waveform from MAX to MIN,
and MIN to MAX by pushing the (+) or (-) tracking button,
and check a flat response is cbtained on the waveform.
é) If a flat response cannot be obtained, roughly adjust the
Tighten the screw @ to eliminate wrinkles from the tape of
the retain guide flange area.
flange area for wrinkles.
(1) No wrinkle is present.
Turn the screw ® clockwise to generate wrinkles on the
tape at the flange area, and then back off the screw @®
as far as the wrinkles are just eliminated.
(2) Wrinkles are present.
f
—
Turn the screw @ counterclockwise as far as the wrin-
kles are just eliminated. _
Reference: .
If the screw @ is turned clockwise, 'wrinkles will be
produced on the lower flange.
Notes:
1. Place the tracking control in the center position, and adjust the
2,
21
Loosen the setscrew
a
Pt
Figure 4-32.
Figure 4-33.