Sony Betacam SX DNW-A100 Maintenance Manual page 236

5-3. Video Head Tip Protrusion Check
Setting of Head Tip Protrusion Measurement
Gauge
n
Being careful not to damage the tape-running surface and
video heads of the drum, set the gauge.
1. Turn the upper drum manually counterclockwise (3)
to align the screw hole to the rib of the threading ring
as shown in Figure 2.
n
The upper drum position is determined as described above
to put the probe of the head tip protrusion measurement
gauge on the absence of a head. The following video head
is first measured the protrusion value.
DNW-A100/A100P: PB A3 head
DNW-A50/A50P: PB A4 head
DNW-A45/A45P: PB A4 head
2. Check the value that the dial gauge pointer reads.
3. Position a probe between the PB B2 head and head.
(Refer to Figure 2.)
4. Press the tip of two legs against the outer circumference
of the drum's upper surface while keeping the base plate
of the measurement gauge in parallel with the upper
surface of the drum. Be sure to keep the probe of the
measurement gauge sufficiently away from the drum.
5. Lower the measurement gauge slowly until the ridges
of the two legs and positioning flange touch the upper
drum while pushing two legs against the outer circum-
ference of the drum's upper surface (applying force
slightly to the measurement gauge in the direction
indicated by the arrow). (Refer to Figure 3.)
m
. Before placing a measurement gauge on the drum, ensure
that the adjustment screw has been loosened fully.
. Perform carefully and slowly so that the probe of a
measurement gauge does not touch the outer circum-
ference or video head on the drum. (Lower so that
the probe is slightly higher than the two legs.)
6. Check to see the followings:
. The probe is in the middle of the adjacent heads.
. The positioning flange adheres closely to the outer
circumference of the drum's upper surface.
. The legs adhere closely to the outer circumference
of the drum's upper surface.
. The value that the dial gauge pointer reads is the
same as before setting (in step 2).
5-14
7. Turn the adjustment screw clockwise until the dial
gauge pointer rotates approximately a half turn.
8. Turn the outer circumference of the dial gauge to align
zero (0) to the pointer.
Drum
Screw hole
PB A4 head
PB A3 head (DNW-A100/A100P only)
Figure 2. Setting of Drum Position
Base plate
Leg
Screw hole
Leg
Drum
Figure 3. Setting of Head Tip Protrusion Measurement Gauge
Rib
PB B2 head
Dummy head
Adjustment screw
Dial gauge
A
Cover
Positioning
flange
Drum
Probe
DNW-A100/A50/A45
DNW-A100P/A50P/A45P