7.2. MECHANICAL ADJUSTMENT
7.2.1. CLEANING PROCEDURE FOR THE
UPPER CYLINDER UNIT
1. While
slowly
turning
the
Upper
Cylinder
Unit
counterclockwise by hand, gently rub the Video Heads with
a Head Cleaning Stick (VFK27) moistened with Ethanol.
When using a Cleaning Cassette, make sure to use "DRY"
type only and be aware that excessive use can shorten
head life.
Fig. M1
Note:
a. Do not rub vertically or apply excess pressure to the
Video Heads.
Do not turn the Upper Cylinder Unit clockwise while
cleaning.
b. After cleaning, use a Dry Head Cleaning Stick (VFK27)
to remove any Ethanol remaining on the cylinder tape
path. Otherwise, tape damage will occur.
7.2.2. ADJUSTMENT PROCEDURES
7.2.2.1. BACK TENSION CONFIRMATION
Purpose:
To fine adjust the Back Tension so that
the tape runs smoothly with a constant
tension.
Symptom of
Misadjustment:
1) If the tape tension is less than the
specified value, the tape cannot come
into proper contact with the Video Heads,
resulting in poor picture playback.
2) If the tape tension is too high, the tape
will soon be damaged.
Equipment
Required:
Back Tension Meter (Made in U.S.A.,
Purchase Locally)
VHS Cassette Tape (120-Minute Tape)
Specification:
20 gf±2.5 gf
(0.196 N±0.025 N)
1. Play back a T120 cassette tape from the beginning for
approx. 10 to 20 seconds to stabilize tape movement.
2. Insert a Tension Meter into tape path and measure the back
tension.
Fig. M2-1
3. If the reading is out of specification, make sure that there is
no dust or foreign material between the Brake Pad of
Tension Control Arm Unit and the S Reel Table.
After cleaning, the reading of tension measurement is still
out of specification, replace the Tension Arm Unit and the
Tension Control Arm Unit.
Fig. M2-2
Note:
a. Be sure that the three probes of the meter are all in solid
contact with the tape, but not touching any other parts of
the mechanism.
b. It is recommended that measurements should be
repeated at least three (3) times because the tension
meter is very sensitive to external vibrations.
41
PVQ-1310 / PV-C1320 / PV-C1330W / VV-1300 / VV-1310W / PV-C1340 / PV-C1350W / PV-C2010 / PV-C2020 / PV-C2030W / VV-2000 / PV-C2060
