Akai 4400D Service Manual

FREQUENCY
COUNTER
Fig. 17
3. RECORDING BIAS FREQUENCY
ADJUSTMENT (See Fig. 18)
1) Set the recorder to recording mode.
2) Connect a Frequency counter to points (A) and
(C) in Fig. 18 of the Oscillator P.C. Board (LE-
$021) and read the frequency indication.
3) If the bias frequency is 105 kHz +5%, the bias
frequency is correct.
4) If the bias frequency is incorrect, it can be ad-
justed by changing the value of condenser C8
(5600 PF) of the oscillator P.C. Board (LE-5021).
4,RECORDING BIAS VOLTAGE ADJUST-
MENT (FREQUENCY RESPONSE
ADJUSTMENT) (See Figs. 17, 18)
1) Set the Monitor switch to “TAPE” position and
Equalizer switch to 7-1/2 ips.
2) Connect an Audio Frequency Oscillator to the
line input through an Attenuator and’ a High
Sensitivity V.T.V.M. to the line output.
3) Load a blank test tape “AKAI 100L” (Fuji S-100)
and set the recorder to “REC” mode.
4) Turn recording level control volume’ VR1I and
VR2 ($0 kA) to obtain 4 dB V.T.V.M. reading.
5) Under conditions described in Item 4) above,
readjust attenuator so that the line output level
is —16 dB.
6) Record from 40 to 20,000 Hz spot frequencies.
7) Adjust Bias Adjustment semi-fixed condenser C6
(70 PF max.) so that the output of 1,000 Hz
and 15,000 Hz frequencies are equal.
8) The bias voltage at this time is around 11V A.C,
5. ERASE VOLTAGE
1) Set the recorder to “REC” mode.
2) Connect a V.T.V.M. to points (B) and (C) in
Fig. 18 of the oscillator P.C. Board (LE-5021)
and read the V.T.V.M. indication.
3) The Erase Voltage is around 52V A.C.
13

Akai 4400D Specifications

General

Brand	Akai
Model	4400D
Category	Tape Deck
Language	English