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The
tape-transport
system
has already been precisely
adjusted by the manufacturer, and therefore no adjustment
should normally become necessary.
Such
checking
and adjustment
may
however
become
necessary when, after long use, a component part of the
tape-transport system is replaced, etc.
(1) Cleaning the tape-transport system
Tape residue, dust and dirt may accumulate in the tape-
transport system after long use. Check the tape-transport
system after cleaning the tape contact surfaces.
(2) Test points when adjusting tape transport
Make the tape transport adjustments while monitoring the
envelope (RF output waveform)
and the audio output
waveform.
@ When monitoring the envelope (RF output waveform),
connect the oscilloscope to N1008 (on the VD-1 board) as
follows:
Pin (1): envelope
Pin (2): ground
Pin (3); RF switching pulse (for trigger)
@ When monitoring the audio output waveform, connect
the oscilloscope to the audio output terminal on the VD-1
board (rear panel terminal).
Entrance side tape guide
iG
Ay.
r
Full-erase
Video head
head
=
drum
O
©
Audio/control head
Impedance
roller
Back tension lever
Fig. 2-7-1
(3) Checking the tape-transport system
Check the following points by using the two end parts of a
T120 tape.
e Check to be sure that, during playback, the tape is not
out of position upward or downward (from the lead) at the
drum entrance and drum exit. If there is any positional
deviation, adjust the height of the entrance and/or exit
guide.
@ Check to be sure that, during playback, there are no
creases or wrinkles of the tape at the entrance guide, exit
guide, etc. If there appears to be an irregular condition,
adjust the height of the entrance guide, exit guide, etc.
Using the wound part of a T120 tape, record and playback
in the EP mode and check the following points.
e@ Check to be sure that, during playback and reverse
search, there are no creases or wrinkles at each guide. If
there appears to be an irregular condition, make a minor
adjustment of the height at the entrance guide, exit guide,
etc.
@ Check the start of the picture on the TV screen, and the
audio, when there is mode switching such as from rewind to
play, reverse search to play, etc. If there appears to be an
irregular condition, adjust the tape-transport system.
Exit side tape guide
Azimuth screw
Height screw
Tilt screw
Pinch
DOCH
screw
Capstan
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