JVC UX-A10DVD Service Manual page 46

UX-A10DVD
Electric adjustment
Item
Recording BIAS adjustment
Mesurement Forward or reverse
condition
Test tape: AC-514 TYPE
Measurement output terminal:
Recording and headphone terminal
Mesurement
1.Test tape (AC-514 TYPE ,AC-225
procedure
TYPE
recording/pose.
2.Connects in the head for the recording
and to connect 100 with the series and
to measure the current of the bias,
connects with VTVM.
3.The pose is released after sets and the
recording begins. It is adjusted that the
current of the bias reaches the following
value by VR31 for L side at this time and
VR32 for R side.
4.0
Standard AC-225: 4.20
value
AC-514: 4.0
Adjustment
position
Electric characteristic confirmation
Item
Forward or reverse
Mesurement
Test tape: AC-514 TYPE
condition
Measurement terminal:
Mesurement 1. It is confirmed that BIAS1 and 2 are
procedure
switched, and the frequency changes.
2.Test tape (AC-514 TYPE ) is installed,
and recording/makes to the pose.
3.It is confirmed that it is BIAS TP on the
substrate and the frequency is 100Hz
6kHz.
Standard
100kHz
value
Adjustment
position
1-46
and
AC-225 TYPE
)is installed, and makes to
(TYPE )and4.20 (TYPE )
Current of recording bias
BIAS TP on P.C.board
6kHz
Recording reproduction
frequency characteristic
Standard frequency: 1kHz/10kHz
Test tape: AC-514 TYPE
Measurement input terminal: OSC IN
1.Test tape (AC-514 TYPE )is installed,
and makes to recording/pose.
2.Records the recording's releasing the
pose, beginning, and repeating 1kHz
and 10kHz of a standard frequency from
the frequency transmitter.
3.VR31 for L side and VR32 for R side are
adjusted so that the recorded part may
be reproduced and there is a difference
between 1kHz and 10kHz in 1dB }2dB,
and the recording is repeated again.
Output difference
1kHz/10kHz:-1dB
VR31
Deletion current (standard value)
Forward or reverse
State of recording
Test tape: AC-514 TYPE
Measurement terminal:
Erase head's both ends
1.Test tape (AC-514 TYPE )is installed,
and makes to recording/pose.
2.The pose is released and after sets in
the state of the recording, 1W is
confirmed, and connects with the series,
and the deletion current is confirmed
from erase head's both ends to the
erase head.
TYPE : 120mA
TYPE : 75mA
(Srandard: -20dB)
2dB
and
AC-225TYPE