Sony BVW-55 Maintenance Manual page 366

5-5. Video Tracking Check and Adjustment
15. Check the PB head head-to-tape
contact
(1) Turn the power off.
(2) Wait about three seconds and then turn the
power on. The Rec head PB mode is released
due to it.
(3) Connect the oscilloscope.
CH-1 : TP804 (Y RF)/MD-122 board
TRIG : TP807 (Y SW)/MD-122 board
CH-2 : TP805 (C RF)/MD-122 board
TRIG : TP806 (C SW)/MD-122 board
Oscilloscope setting:
CH-1 : 50 mV/DIV
CH-2 : 50 mV/DIV
TIME : 2 ms/DIV
(4) Play back the CR2-1B.
(5) Press S101 switch on the SV-206 board more
than 3 seconds so that the tracking VR
becomes to be effective.
(6) Turn the tracking VR so that the output level
at the center portion of the RF waveform of
a-channel is maximized. (CH-1)
(7) Check that the RF waveform of a-channel
satisfies the specification 5. (CH-1)
(8) Maximize the output level of the RF wave-
form of b-channel by turning the tracking
VR, check that the RF waveform of
b-channel satisfies the specification 5. (CH-1)
(9) Change the connection of TRIG of the
oscilloscope to TP806 on the MD-122 board
and perform the check from procedures (6)
through (8) in the same way. (CH-2)
If the specification 5 is not met, perform the
adjustment (at the Drum Entrance Side or the
Drum Exit Side) in steps 19 and later.
16. Adjust the AT head position
(Refer to Section 5-8.)
17. Check the AT head height
(Refer to Section 5-9.)
n
Be sure to check the AT head position when the
AT head height is adjusted.
18. Check the AT head azimuth
(Refer to Section 5-10.)
5-24
. Connection of the oscilloscope
CH-1 : TP804 (Y RF) _ TRIG : TP807 (Y SW)
CH-2 : TP805 (C RF) _ TRIG : TP806 (C SW)
F E
TP805
TP803
TP802
TP801
. Alignment tape : CR2-1B
(D109 Lit)
CH-1 (Ya, Yb)
CH-2 (Ca, Cb)
TRIG
RF waveform of b-CH RF waveform of a-CH RF waveform of b-CH
B
Spec. 5: The output level of the waveform should be more
than 80 % of the maximum value.
B
> 0.8
A ,
D C
B A
E501
TP807
TP806
TP804
MD-122 BOARD, B Side
Maximize
A
D C
C D
> 0.8 > 0.8
A , A
1
2
3
4
BVW-55 P2