(No.MB286)1-31
4.3.2 Electrical adjustment
4.3.3 Electrical response confirmation
R/P
playback
frequency
response
Recording
BIAS
adjustment
Reference frequency
: 1kHz / 10kHz
(Reference: -20dB)
Test tape
: AC-514 TYPE
Input terminal
playback
frequency
response
1. Set the test tape(AC-514 TYPE and
AC-225 TYPE ), then make REC/PAUSE
condition.
2. Connect 100 to recording head by series,
then connect to VTVM for measurement
the current.
3. After setting, start the recording by release
the PAUSE, in this time bias current adjust
to next fig. by VR31 for Lch and VR32 for
Rch.
4.0uA (TYPE ) and 4.20uA (TYPE ).
1. Set the test tape (AC-514 TYPE ), then
make REC/PAUSE condition.
2. Release the PAUSE, then start recording
the 1kHz and 10kHz of reference frequency
from oscillator.
3. Playback the recorded position, 1kHz and
10kHz output deviation should -1dB 2dB
to readjust by VR31 for Lch and VR32 for
Rch.
VR31
VR31
AC-225
:4.20uA
AC-514
:4.0uA
Output
deviation
1kHz/10kHz
:-1dB 2dB
Item
Condition
Measurement method
Ref.value
Adjustment
position
Forward or Reverse
Test tape
:AC-514 TYPE
:AC-225 TYPE
Output terminal
Recording head
1. Set the test tape (AC-514 TYPE and
AC-225 TYPE ), then make REC/PAUSE
condition.
2. Release the PAUSE to REC condition,
connect 1W to ERASE head by series, then
confirm the erase current at both side of
erase head.
1. Change BIAS1 and 2, confirm the frequency
should be change.
2. Set the test tape (AC-514 TYPE ), then
make REC/PAUSE condition.
3. Confirm the frequency should 100Hz 6kHz
at BIAS test point on printed circuit board.
Recording
bias
current
Forward or Reverse
Test tape
: TYPE (AC-514)
Measurement
terminal
: BIAS test point on
printed circuit board
Erase
current
(reference
value)
Forward or Reverse
Rec condition
Test tape
: AC-514 TYPE
: AC-225 TYPE
Measurement
terminal
: Both side of Erase
head
TYPE
: 120 mA
TYPE
: 75 mA
100 kHz
6 kHz
Item
Condition
Measurement method
Ref.value
Adjustment
position
