Record Mode
(Erase Head)
Measurement condition:
Power voltage
Volume control
Maximum
Instruments required:
SIGNAL SOURCE
CONNECTION
DC 6 V or AC 100~250V
OUTPUT
CONNECTION
ADJUSTMENT
REMARKS
Head angle
adjustment.
Thread the 3kHz
alignment tape.
VTVM with 8Q
resistor to EXT SP
jack.
See fig. 7.
Playback
Head angle
adjustment
screw @.
Maximum
Measurement of
erase current.
VTVM to both
terminals of erase
head.
See fig. 8.
Record
Measurement of
recording bias
current.
VTVM with 10Q
resistor.
See fig. 9.
Record
Bias current (0.5 mA)
_ Voltage value (5mV)
Resistance value
Q)
Measurement of
recording level.
1kHz —73 +5dB
to MIC input jack.
VTVM with 10Q
resistor.
See fig. 10.
Stop the bias osillation
by unsoldering R27.
Measurement
of
playback amplifier
gain.
1kHz —78 +3dB
to head lead wire.
| See fig. 11.
VTVM with 80
resistor to EXT
input jack.
Playback
Measurement of
bias oscillator
frequency.
R (100) &
Oscilloscope with
AF OSC.
See fig. 12.
Adjust the AF OSC so
that the Lissajous' figure
on oscilloscope becomes
a stationary circleand
the oscillation frequency
is indicated by the scale
of the AF OSC.
10
