1-D. Azimuth Alignment Of Audio/Control/Erase Head; 1-E. Checking And Alignment Of Tape Path During Reversing - Hitachi DV-PF7E Service Manual

1-D. Azimuth Alignment of Audio/Control/
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-2) 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 oscil-
loscope is at maximum. (Fig. 5-4-6)
Note: Upon completion of the adjustment of Azimuth
Adj. Screw, check the X Value by pushing the CH UP
or DOWN buttons alternately, to check the symmetry
of the envelope. Check the number of pushes to
ensure preset position. The number of pushes CH UP
button to achieve 1/2 level of envelope should match
the number of pushes CH DOWN button 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 dur-
ing 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 proce-
dure. If the unit is not correctly aligned, the tape may
be damaged.
1. Insert a black 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. 5-4-11 and 5-4-12.)
2. When the tape has been curled up or bent, turn
the alignment screw to adjust the height of REV
Post. (Refer to Fig. 5-4-11 and 5-4-13.)
Take-up Guide Post [4]
Correct
REV Post
Tape
Take-up Guide
Post
Tape
5-8
REV Post [5]
Fig. 5-4-11
Incorrect
Fig. 5-4-12
Alignment
Screw
Tape Guide
Assembly
Fig. 5-4-13