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Toshiba V-854G Serviceanleitung Seite 47

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b. ACE tilt adjustment
1. Observe the lower flange of No. 8 guide. If any
wrinkle is observed, turn the ACE tilt adjusting
screw counterclockwise until the wrinkle disap-
pears.
2. Ifa gap is observed between the lower flange of
No. 8 guide and the lower edge of tape, turn the
ACE tilt adjusting screw clockwise until the tape
travels along the lower flange.
Note:
© This adjustment is performed easily in SP mode
playback, double speed playback mode or CUE mode.
c. Audio head height check
1. Play back the stereophonic alternative recorded
300 — 500 Hz audio signal as described in the step
4)-a, and check if the audio envelope is flat. If not,
repeat the adjustment described in step 4)-a again.
d. Audio azimuth adjustment
1. Play back the 400 Hz, 7 kHz audio signal on the
alignment tape.
2. Tum the ACE azimuth adjusting screw until the
maximum audio output is obtained.
e. Audio head hight check
1. Play back the alignment tape desribed in step 4)-a
and check if the audio envelope is flat. If not,
tepeat the adjustment described in step 4)-a.
Note:
« If there is no alignment tape (ST-C6, ST-C7), perform
the audio height alignment using the current alignment
tape at this adjustment step.
1, Playback the 400 Hz audio signal (SP mode) on
the alignment tape.
2. Tum each three alignment screw of the ACE head
to the same direction in 45 degrees steps evenly so
that the audio output level becomes maximum.
3. Perform the confirmation and adjustment for the
tilt and the azimuth again.
f. ACE head postion adjustment
1. Play back the white envelope (LP mode) on the
alignment tape.
2. Push the channel (tracking) up/down buttons
simultaneously and reset the tracking at its center
position.
2-42
3. Trigger the oscilloscope with the video switching
pulse and observe the video envelope waveform.
4, Slide the ACE main base until the maximum
envelope output is obtained as described in ACE
head position coarse adjustment.
5. Play back the 2 MHz video signal (SP mode) on
the alignment tape.
6. Make sure the envelope output is maximum when
the tracking control is placed at its center position.
If no envelope output is obtained with the tracking
control set to the center position, again adjust it for
maximum envelope output in SP and LP modes.
When envelope output is maximum in the LP
mode at the tracking center, difference with the
case in the SP mode is within 3 ms.
7. Tighten the ACE head position fixing screw and
secure the ACE main base.
g. After completion of ACE head fine adjustment,
apply screw lock to two screws (tilt, azimuth
adjusting screws) in front of the ACE head.
5) No. 9 guide lever adjustment
1. Set the VTR to Cue mode with E-240 tape (at
beginning portion) loaded. Switch the Cue mode to
the review mode when the tape has been rewound
into the T-reel table to some extent.
2. Check tape wrinkle at the upper and lower flange
of No. 8 guide. Check the tape does not come off
from the flange while running. If the tape comes
off from the flange, replace the pinch lever,
capstan motor or No. 9 guide lever since the part(s)
is (are) defective.
Note:
+ Modify the lid of the cassette for the alignment tape E-
240 previsously so that the alignment is performed
easily.
6) Check for transitional operation from Review
to Play, slot-in to play
1, Play back the LP mode white video signal on the
alignment tape in Review mode and observe the
video envelope with the oscilloscope.
2. Switch the Review mode to the Play mode. When
switched to the Play mode, make sure the entrance
side envelope comes to an approximate steady
state within 3s as shown in Fig. 7-3-9.
If it does not rise within 3s, take the following
Steps starting 4).
3. Switch the cassette slot-in mode to the Play mode.
As in item 2), if it does not rise within 3s, adjust as
follows.
Envelope (entrance side)
Fig. 7-3-9 Video envelope rising when operation mode
is switched from review to play mode
4. Adjust the S guide roiler and perform the linearity
adjustment again.
5. Check above items 2) and 3) to see that the video
envelope rises within 3s. If not, S slider assembly
or the tension lever is damaged. Replace either (or
both) of them.
Note:
+ If the rising characteristic is poor in Review mode,
screen noise may occur in synchronous editing
tecording. Perform the adjustment carefully.
7) Envelope check
1. Make recordings and play back the tapes (E-180
and E-240) in SP and LP modes and make sure the
playback output envelope meets the specifications
shown in Fig. 7-3-5.
2. In playback the tape (with a E-180), the video
envelope should meet the specification as shown in
Fig. 7-3-10.
Note:
* Check for both modes, SP and LP. Also check for
AFM envelope when using a Hi-Fi model.
+ Es
* BA = 0.55
* B= 120mv
Fig. 7-3-10 Envelope output and output difference
3. If the performance does not meet both specifica-
tions above | and 2 above, replace the upper
cylinder assembly.
2-43
4. Set the VTR to Rec mode (LP) with the E-180 tape
loaded (at the beginning part) and check operation
of the synchronous editing recording.
5. If picture noises are observed at the starting
position of the editing, perform ''6) Check for
transitional operation from Review to Play, slot-in
to play".
8) Tape wrinkle check
1. Playback the E-240 tape in the normal Play mode,
CUE mode, Review mode and the frame advance
mode, and check each guide for wrinkle.
2. If excessive tape wrinkle is observed at the mode
shown below, perform the associated adjustments
also shown below. (The parts described in ( ) may
need to replace.)
a. Playback mode
Tape wrinkle at the S, T-guide rollers section
Item 3) Linearity adjustment
+ (Slider assembly)
Tape wrinkle at No. 8 guide flange
Item 1) ACE head assembly coarse adjustment
(Pinch roller)
Tape wrinkle at lower flange of No. 1 guide
Item 6) Check for transitional operations from
Review to Play, and Slot-In to Play
(Tension lever)
b. Review mode
Tape wrinkle at No. 8 guide
Item 1) ACE head assembly coarse adjustment
(Pinch lever, No. 9 guide lever,
capstan motor)
Tape wrinkle at the guide rollers
Guide roller adjustment (Slider assembly)
c.
Frame advance mode
Tape wrinkie at No. 8 guide
Item 3) Linearity adjustment
(Pinch lever, capstan motor)

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V-804g