Akai X-1810

Vil. AMPLIFIER ADJUSTMENT
A-l.
A-2.
A-3.
ADJUSTMENT OF RECORDING BIAS
FREQUENCY (See Fig. 1)
Put on the resistor 1 or 2 Ohms in series with the
Bias Head and connect the Vertical Input Terminal
of the Oscilloscope to points (a) and (b).
Feed in a sine wave signal from an Audio
Frequency Oscillator to the Horizontal Input of
the Oscilloscope and tune the Dial of the Audio
Frequency Oscillator until the Oscilloscope dis-
plays a circular or linear pattern. Then read the
figure on the Dial of the Audio Frequency
Oscillator.
If it reads 65 KH +5 KH, the Recording Bias
Frequency is correct.
. In case the recording bias frequency is incorrect,
it can be adjusted by changing the value of C402
(1700p).
OSCILLATOR CIRCUIT
AUDIO FREQUENCY
OSCILLATOR
OSCILLOSCOPE
C403 0.01
In certain instances, Bias Frequency is measured
by connecting the Frequency Counter, leader wire
to points (a) (b) as shown in Fig. 1 and reading
the Frequency Counter indication.
ADJUSTMENT OF RECORDING BIAS
VOLTAGE
Reel Only (Ref. Fig. 2)
Connect a V.T.V.M. to point (a) and Ground and
adjust the recording bias voltage by turning Li in
the bias oscillator circuit until the V.T.V.M. read-
ing is the same as is stamped on the rear side of
the head assembly.
Note: There is no way of adjusting the erasing
bias voltage, but the correct voltage is AC
65V +5V. (Check point: Both sides of
erase head).
(Ideal Adjustment of Recording Bias voltage
is determined by Frequency Response and
distortion)
Cartridge
There is no way of adjusting cartridge Recording
Bias Voltage, but Bias Voltage is about 8 to 10V.
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