Hitachi DV-PF35U, Руководство по обслуживанию

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4-8
1-D. Azimuth Alignment of Audio/Con-
trol/ Erase Head
Purpose:
To correct the Azimuth alignment so that the Audio/
Control/Erase Head meets tape tracks properly.
Symptom of Misalignment:
If the position of the Audio/Control/Erase Head is not
properly aligned, the Audio S/N Ratio or Frequency
Response will be poor.
1. Connect the oscilloscope to the audio output jack
on the rear side of the deck.
2. Playback the alignment tape (MH-1) and confirm
that the audio signal output level is 8kHz.
3. Adjust Azimuth Adj. Screw so that the output level
on the AC Voltmeter or the waveform on the oscillo-
scope is at maximum. (Fig. M6)
Note: Upon completion of the adjustment of Azimuth
Adj. Screw, check the X Value by pushing the “CH
K
”
or “CH
L
” buttons on the unit alternately, to check the
symmetry of the envelope. Check the number of
pushes to ensure preset position. The number of
pushes “CH
K
” button on the unit to achieve 1/2 level
of envelope should match the number of pushes
“CH
L
” button on the unit from center. If required, redo
the “X Value Alignment.”
1-E. Checking and Alignment of Tape
Path during reversing
Purpose: To make sure that the tape path is well
stabilized during reversing.
Symptom of Misalignment: If the tape path is
unstable during reversing, the tape will be damaged.
Note: Do not use an Alignment Tape for this
procedure. If the unit is not correctly aligned, the tape
may be damaged.
1. Insert a blank cassette tape into the tray and set
the unit to REV. Then confirm if the tape has been
curled up or bent at the Take-up Guide Post[4] or
REV Post[5]. (Refer to Fig. M11 and M12.)
2. When the tape has been curled up or bent, turn
the alignment screw to adjust the height of REV
Post. (Refer to Fig. M11 and M13.)
Take-up Guide Post [4]
REV Post [5]
Fig. M11
Take-up Guide
Post
Tape
REV Post
Tape
Correct
Incorrect
Fig. M12
Fig. M13
Tape Guide
Assembly
Alignment
Screw