Akai X-V User manual

TABLE OF CONTENT Page
I SPECIFICATIONS . . . . . . . . . . . . . . . . . . 1
II MEASURING METHODS . . . . . . . . . . . . . 2
III CONTROL LOCATIONS . . . . . . . . . . . . . . 4
IV DISMANTLING OF TAPE TRANSPORT
UNIT & AMPLIFIERS . . . . . . . . . . . . . . . 5
V TAPE TRANSPORT MECHANISM . . . . . . . . 7
VI MECHANISM ADJUSTMENT . . . . . . . . . . .
11
VII AMPLIFIER ADJUSTMENT ............ 14
VIII HEAD ADJUSTMENT ............... 18
IX MAINTENANCE PROCEDURE .......... 18
X TROUBLE SHOOTING
CHART .......... 19
XI REPLACEMENT PARTS TABLE ......... 21
XII SCHEMATIC DIAGRAM

1.. SPECIFICATIONS
SPECIFICATIONS
STYLE
WEIGHT
DIMENSIONS
POWER SUPPLY
Portable
12.1 lbs (5.5 kg) without battery
Battery ... 1.3 lbs (0.6 kg)
5-1/8"x 11" x 12" case closed
(130 x 280 x 300 mm)
AC 100 to 240 V 50/60Hz
DC ... Rechargeable Battery (6 V, 2.6 AH)
RECORDING SYSTEM
PLAY BACK SYSTEM
TAPE SPEED
In-line 4-track stereo, monaural recording
with Cross-field
Bias Head
ln-line 4-track stereo, monaural playback
4 speeds
7-1/2" (19 cm), 3-3/4" (9.5 cm),
1-7/8" (4.75 cm)
and
15/16" (2.375 cm)
TAPE SPEED DEVIATION
WOW AND FLOTTER
(Play back only)
Within ±
3%
Less than 0.15% r.m.s. at 7-1/2"
Less than 0.17% r.m.s. at 3-3/4"
Less than 0.25% r.m.s. at 1-7/8"
Less than 0.35% r.m.s. at 15/16"
FREQUENCY RESPONSE
40 to 20,000
Hz± 3 dB at 7-1/2"
40 to 17,000 Hz± 3 dB at 3-3/4"
40 to 11,000 Hz± 3 dB at 1-7/8"
40 to 5,500
Hz± 3 dB at 15/16"
SIGNAL TO NOISE RATIO
DISTORTION
(Total Harmonies)
CROSS TALK
Better than
50 dB (DC)
Better
than 45 dB (AC)
Within
5% at 20 dBm output power
(each tape speed)
Less
than- 70 dB (Monaural)
Less
than- 50 dB (Stereo)
ERASE RATIO Less
than- 70 dB
INSULATION RESISTANCE
More than
50 M. Ohms
INSULATION DURABILITY
POWER OUTPUT
500 V
AC for more than one minute
duration
MAIN OUTPUT : 2 W maximum per each channel,
total4 W
DIN OUTPUT
INPUT LEVEL
LINE INPUT
MIC. INPUT
DIN INPUT
Impedance ....... 8 Ohms
0.5 V
at Volume maximum
Impedance
....... 3.5 K. Ohms
50 rn V at 0 VU indication
Impedance
..... 220 K. Ohms
0.5
mV at 0 VU indication
Impedance
..... 3.9 K. Ohms
20
rn V at 0 VU indication
Impedance
..... 82 K. Ohms
FAST FOR WARD AND
REWIND TIME : 145 seconds for 600 foot tape
MONITOR SYSTEM: Program being recorded can
be monitored by using
Stereo Headphone
MOTOR DC brushless servo motor
HEADS
REC/PLAY HEAD
BIAS HEAD
ERASE HEAD
Revolutions
... .". 3,000 r.p.m.
Control circuit
... 8 transistors
and 4 diodes used.
In-line 4-track stereo/monaural
Gap
... 2 micron
Impedance
... 860 Ohms at 1,000 Hz
In-line 4-track stereo
Gap
... 0.2 mm
Impedance
... 360 Ohms ± 30 Ohms
at 50 KHz
In-line 4-track stereo
Gap
... 0.2 mm
Impedance
... 360 Ohms ± 30 Ohms
at 50 KHz
RECORDING LEVEL INDICA TOR
TRANSISTORS
2
VU meteres
4 2SC650A
1 2SC828R
6 2SB370B
2 2SC538
3 2SB367
4 2SC281B
2 2SB77B
2 2SB75B
3 2SB346
GERMANIUM DIODES
7 IN-34A
SILICON DIODES 2 lOD-1
BS-2, bridged silicon diode rectifier
SELENIUM RECTIFIER
16C-4, bridged selenium rectifier
ZENER DIODES 1 10Z68
RD-6A
LOUDSPEAKERINCLUDED
REELS USED
3" round dynamic speaker
Impedance
..... 8 Ohms
7'', 5", 3" reels

Il. MEASURING METHOD
1. TAPE SPEED DEVIATION
1. Method involving use of pre-recorded tape.
Playback on the tape recorder to be tested a tape
pre-recorded
at 1,000 Hz ± 0.1% for measuring tape
speed deviation. Connect the appropriate
output to a
frequency counter me ter in arder
to measure the tape
speed deviation from the deviation
of the ~easured
frequency.
2. Method involving use
of timing tape (designed for
tape speed measurement).
This
method utilizes a timing tape marked at intervals
of 7-1/2". The running time of the tape over 60
marked section is measured in arder to calculate the
deviation
of the tape speed. In applying this method,
however,
it should be born in mind that should the
timing tape stretch or contract, measurement error
is
inevitable, so that it is necessary to measure the total
length
of the tape in advance.
2. WOW AND FLUTTER
Playback the 3,000 Hz pre-recorded tape whose wow
and flutter level
is guaranteed to be smaller than 0.07%
for measurement by means of a wow meter. It is also
possible for a 3,000 Hz sine wave to be recorded and
played for measurement
by means of the wow meter. In
this case, however, the wow meter indicates a value
as
twice the value given in the specification on the first
page.
3. SIGNAL TO NOISE RATIO
X-V
Line output
V.T.V.M.
Set the speed selector Switch on "7-1/2" ips position
and playback a tape containing a 1,000 Hz sine wave
recorded at
"0" VU level on a standard recorder.
Connect a V.T.V.M. to the line output jack of the
recorder and measure its
output.
Then remove the tape and measure the noise level under
the same condition. Convert each
of the measured values
into decibels.
4. TOTAL HARMONIC DISTORTION
FACTOR
1 Kc/s
Audio Distortion
--
X-V
--
Oscillator me
ter
Connect the measuring instrument as shawn above, and
record the 1,000
Hz sine wave at "0" VU. Playback the
resultant signal and measure the overall distortion factor.
Measure the noise level
of the tape recorder with the
tape removed ; connect the audio oscillator directly to
the distortion meter for measurement
of the distortion
factor
of the oscillator.
The required distortion factor may be
obtained from the
results
of the above measurement by the following
formula.
do=d-d1-d2
where, d0=Requred
d=Overall distortion factor
d1 =Noise level
d2 =Distortion factor of the oscilla tor
(Note : New tape of particularly good quality should be
used for measurement of the distortion factor.)
5. POWER OUTPUT
Playback the tape pre-recorded with a sine wave of
1,000 Hz at "0" VU, and connect an sn load resistor to
the
output terminais of the tape recorder : measure the
voltage across the resistor with the volume control set to
maximum. Use the following formula
to obtain the
required
output :
E2
W=R
Where, W .......... Output (watt)
E ........... Output voltage
R
........... Resistor (Sn)
(Note : The sn resistor used in this measurement must
be
of high precision).
6. CROSS TALK
(Cross talk between the tracks)
(TAPE)
CD
(
@'
®
®'
Tape direction @ )
®'
@
w~
CD' Tape dir
ection
As shawn in the figure, first record a 1,000 Hz sine wave
on track No. 3 at + 3 VU level. Next, remove the
1,000 Hz input signal and record under a non-input
condition.
Then playback the tape on track No. 3 and No. 1
(reversed condition of tape) through the 1,000 Hz
B.P.F. (Band Pass Filter) and obtain a ratio between the
two from the following formula.
Eo
C = 20 log-- (db)
E2-E1
C=Desired cross talk ratio (db)
E0= 1,000 Hz signal output level
E2= 1,000
Hz cross talk output level
E1 =No-input signal record level

7. FREQUENCY RESPONSE
Audio
X-V
Frequency A.T.T. Line
Input
V.T.V.M.
Oscilla
tor
Line Output
Connect the measuring instrument as shown above
diagram, and measure the frequency response in the
following sequence :
RECORD:
1) Give a sine wave of 1,000 Hz to the Line Input of the
recorder to be tested, through an attenuator from
an
audio frequency generator.
2) Set the Start and Record Knob in
to "Rec" position
and adjust the line input volume
so that the VU
meter needle indicates "0" VU.
3) Under the condition described in (2), lower the input
10 db by me ans of the attenuator.
4) Record the spot frequency in the range
of 30 Hz to
25,000 Hz from the audio frequency generator.
PLAYBACK:
5) Set the Record/Playback Knob in to "Play" position.
6) Set the Speed Selector Switch on 7-1/2" or 3-3/4"
position.
7) Connect a V.T.V.M. and 8[2 resistor across the
speaker terminal.
8) Playback
the tape previously recorded.
9) Adjust the output level
to "0" dbm at 1,000 Hz as
indicated on the V.T.V.M. by the range selector of a
V.T.V.M.
10)
conditions in (9) ; make a memo of output level and
plot the value on a graph.

Ill .. CONTROL
ONS
Supply Reel Shaft--------------------,
Trad: Selector -----------------,
Head Cover-------------------.._
Fast Fonvard Button------------...
S tart Button --------------------.
Stop Button-----------------..
Record Button-------------... ...
Re,,·ind Button------------,~' 1
VU 1\Ieter(Right)-----
VU Meter(Left)-----
Tone Control(Left)----
Amplifier Switch/Volume
Control( Le ft)
Input Jack( Left)
Input Selector--------'
Volume Control(Right;-~-
Input Jack( H.ight)------~
Tone Control(H.ight)-------
Tape Speed Selector----------'
Battey Voltage Indicator Meter---'--
Battery Charge lndicator-------_:
Take- up Heel Shaft
:..:=:-------Heset Button
'--------Index Counter
--------Tape Holder

IV.. DISMANTLING OF TRANSPORT UNIT &
AMPLI FIERS
a
1) Remove RETAINING SCREWS (marked (a) and
(b)) by using a Philips-head screw driver and
remove UPPER FRAME.
3} Remove RETAINING SCREWS (marked (a) and
(b) )
by using a Philips-head screw driver and
remove DECK PANEL.
5) This picture shows ali COYER PANELS removed
making mechanism control adjustment accessible.
2) Remove RETAINING SCREWS
(marked (a) and
(b) ) by using a Philips-head screw driver and
remove HEAD COYER.
CASE COVER A
c
d
CASE COVER C
4) Remove RETAINING SCREWS (marked (a) to (d))
by using a Philips-head screw driver and remove
CASE COYERS A &
C.
b d
c
CASE COVER B
6) Loosen RETAINING SCREW (a) and remove CASE
COYER D. Then remove RETAINING SCREWS
(marked (b) to (f)) by using a Philips-head screw
driver and remove CASE COYER
B.

7) Remove RETAINING SCREWS (marked (a) to (d))
by using a Philips-head screw driver and remove
SIDE FRAME
A.
9) Disconnect MULTI JACK (a) and "U'' RING (b),
then, remove RETAINING SCREWS (marked (c) to
(e) )
by using a Philips-head screw driver. PRINTED
BOARD (X5-502) can now be withdrawn. Adjust-
ments
or repairs on the front panel and speakers are
possible.
PRINTED BOARD
(X5-504)
11) Remove RETAINING SCREWS (marked (a) to (c))
by using a Philips-head screw driver and remove
PRINTED BOARD BLOCK (X5-504).
SIDE FRAME B
8) Remove RETAINING SCREWS (marked (a) to ( d))
by using a Philips-head screw driver and remove
SIDE FRAME
B. FRONT PANEL with
SPEAKERS may now be removed.
1
0) This picture shows PRINTED BOARD (X5-502)
removed from the case. Any adjustments and repairs
are possible.
12) This picture shows accessibility for any adjustments
and repairs on X5-504 PRINTED BOARD.

V. TAPE TRANSPORT MECHANISM
;=:JV ~ REMOTE
~ CONTROL
SW-3 CONTAINED IN AC. PLUG
SW-4 AC. SWITCH
to
AMP.
SW-7 CONTAINED IN VOLUME CONTROL
SW-8 MICRO SWITCH Fig. 1
Fig. 2

Fig. 2
1. START MODE (Playback)
As shown in Fig. 2, when Start Key (A) is pressed, all
levers from (B) through (K), illustrated in yellow
diagram, operate almost simultaneously. The Pin located
on the tip of Lever (G) pushes SW-5 as shown in Fig. 3,
causing the
motor to rotate. Motor rotation is transfered
to Pulley (J) by means of the Drive Belt. When Lever (I)
of Take-up Reel Spindle is pushed in the arrow marked
direction by Lever (E), it engages the Inner Wheel
of
Take-up Reel Spindle which is then pressed downward
Fig. 3
to contact Pulley (J). The Take-up Reel Spindle rotates
counterclockwise to take up tape.
During other operation, the Pin on Lever
(F) sets SW-6
to the "open" condition, as shown in Fig. 3, and pushes
SW-8 (a rnicroswitch). As this time, when switch SW-7,
which is linked with Volume Control, is set to "ON",
current flows to the amplifier through SW-7 & 8 from
Battery or
AC power source. When Lever (E) is operated
as shown by the arrow marked direction in Fig. 2,
Lever (R) operates as shown by the arrow mark in Fig. 3
so
that Lever (P) is disengaged from "lock" position.

Lever (P) is moved by spring force so that the 5-step
Pulley (B) cornes in contact with Flywheel (S).
The 5-step Pulley
is motor driven by means of a square
type drive belt, transfering the
rotation from the motor
pulley to the flywheel, causing the flywheel to rotate.
The shaft
of the flywheel is directly connected to the
capstan, so
that the capstan (Y) begins to rotate
simultaneously. Lever (D) is moved by spring force and
Pinch Raller (Z) presses the tape against Capstan (Y)
transporting tape
at constant speed. The tape pressure
pad which
is installed on Lever (K), pushes the tape
against Erase Head
and creates hold back tension. Right
and
Left Brake Levers (H) are actuated by Lever (G) as
shawn by the arrows so that brakes are disengaged from
reel plates.
In Fig. 1, each switch operates as follows : SW-3
mounted in the AC Socket, switches off battery current
when the
AC cord is connected. All current is supplied
from Power Line (Alternating Current). When the
AC
cord is disconnected from the socket, SW-3 closes and
current
is supplied from the Battery to motor and
amplifier.
SW-4 installed on the back side of X-V case
operates when
Power Line are utilized. SW-5 is actuated
by Lever (G), being in the "ON" condition during
START, FAST FORWARD and REWIND MODE.
SW-5
contrais the current of the mo tor circuit and when SW-5
is "ON", the mo tor rotates. Adjust mo tor rotation
L
during START MODE to 3,000 r.p.m. with potentio-
meter VR-1.
SW-7 which is linked with the volume control, controls
power source
of the amplifier.
A micro switch, SW-8, connects the amplifier during
Start Mode, while during Fast Forward and Rewind
Mode
it connects the motor circuit through a Diode.
Since power consumption
of the motor increases during
Fast Forward and Rewind Mode, it is neccessary to
increase the
motor torque by connecting all power
sources
to the motor circuit.
2. RECORD MODE
As shawn in Fig. 2, when Start Key (A) and Record
Key (T) are depressed simultaneously, Levers which are
illustrated in yellow and red
on the diagrams are set to
Record Mode.
Lever (U) pushes Bias Head (X)
toward Recording
Head (W), while Recording Lever (L) pushes the slide
switch (SW-201)
of Pre-amplifier into recording
condition.
When SW-201
is set to Record Mode, voltage is supplied
to the Bias Oscillator circuit and the Bias Oscillator
begins
to operate. Erase current then flows through
Erase Head, and Bias
current flows through Bias Head,
establishing the recording condition.
SW-5
Fig. 4

Supply Reel Shaft
3. FAST FORWARD AND REWIND
FUNCTION MODE
a) FAST FORWARD MODE
Rew.~F.F.
As shawn in Fig. 4 when the Fast Forward Key (A) is
depressed, levers marked (B) to (G) operate simt:1ta-
neously.
When Lever (G) maves in the direction
of the arrow,
SW-5 is set to the "ON'' condition and the motor begins
to rotate. At this time SW-6 contact points are closed
and
motor rotation reaches about 4,000 r.p:m.
Lever (G) actuates Brake Lever (H) and releases the
brakes from right and left reel plates. Pulley (J)
is driven
by a round type drive belt, beginning to rotate simulta-
neously with the motor. Refer to the side view illustra-
tion
of Fig. 5 for explanation of lever operations,
located near by Reel Spindle.
When Lever (E) maves in the direction
of the arrow, Bar
Spring (K) pushes Pin (L) and the Pulley Shaft and Shaft
Bolder move toward Take-up Reel Shaft. Pulley (J)
firrnly contacts the rubber wheel of the Take-up Shaft, ·
and Torque of the Pulley is transfered to the Take-up
Reel Shaft, perrnitting Fast Forward operation.
4. REWIND MODE
As shawn in Fig. 4, when Rewind Key (M) is depressed,
Levers (N) and
(0) move in the direction of the arrow.
In Fig. 5, Bar Spring (P) pushes Pin (R) and Pulley Shaft
maves toward Supply Reel Shaft. Pulley (S) firrnly
contacts the rubber wheel
of the Supply Reel Shaft,
which begins to rotate clockwise, perrnitting Rewind
operation.
Take-up Reel Shaft
Fig. 5

VI.. MECHANISM ADJUSTMENT
1. ADJUSTMENT OF SPEED CHANGE
MECHANISM (As shown in Fig. 1)
The adjustment of the speed change mechanism is
performed in the following sequence :
1) Set the speed selector knob
éD to the 3-3/ 4"
position and adjust the fixing screws of the switch
levers ® ,
®, and ®, so that the eut portion of
the switch lever ® fits smoothly into the lock
pin ®
of the lock table.
2) At the 7-1/2" position of speed, adjust the switch
lever ®
to me et the lock pin ®.
3) At the 15/16" position of speed, adjust the lock
pin @
to meet the left edge of the switch lever ®
(as observed from the rear).
4)
At the 1-7/8" position ofspeed, loosen the lock pin
nuts © and by moving the lock pin ©
to the left
and right, lock the switch lever ® . (the lock
pin ©
is movable over a distance of 0.8 mm)
Fig.'
2. ADJUSTMENT OF THE SWP
LEVER © (As shown in Fig. 1)
A h 3 3/4, . . f d
ct· ·rews of the
t t e - positiOn o spee , a
JUSt' .t h
. · the
sWl c
lever (S2) and swltch lever ©
to ser
lever @ and the chassis by a distance 1 to 0·
2 mm.
3. ADJUSTMENT OF THE s-P WHEEL
ASSEMBLY (Fig. 1)
a) Adjust the positions of the wheplder tablesh®l
n the w ee
and
CD, so that the clearance wee (GD
holder tables ( ® and CD) and tiVheel holders
and
®) is from 0.1 to 0.2 mm. d
b)
Wh en the 5-step wheel spring cnas been reu:ov~h'
the 5-step wheel should be fAy movable m e
vertical direction.
. . M) f the swi teh
4. The tensiOn of the spnr, ( 0 . th the
lever (D) is to be 100; ± 10 g, W1
spring stretched to a leJgth of 43 mm.

1.
ADJUSTMENT OF FL YWHEEL
(RUBBER-WHEEL) GAP (Fig. 2)
35
37
44-~- l~.g
~~''
~&~40
43 1
42 -41
®
!-39
Fig. 2
Ad
;)~ flywheel shaft thrust plate ® at the upper
:~~tthe _chassis (at the side of the head), so that
10rt10n © of the flywheel shaft does not
come . .
© .c.
ontact wtth the upper mam metal holder
. 1
f"tt d
1
~ or decrease the number of nylon plates ®
th
1 e 1
thrust plate ® underneath the chassis, so
at the
t 0 cal play of the flywheel becomes from 0.1
o .Sm.
6. AD'fMENT
OF BRAKE MECHANISM
(Fig •.
Fig. 3
In the stop c d" .
th
on Itl<J, adjust the brake tension so that
e clearance b .
th
t ecom; approx1mately 0.5
mm between
e
op po Ï
r IOn ® othe brake lever ® and the nylon
rollers © t b h
a
ot end~ of the brake lever © .
7.
ADJUSTMENT OF THE TENSION OF
SUPPLY AND TAKE-UP REEL SHAFT IN
THE PLAYBACK AND RECORD
CONDITIONS. (Fig.
4)
Supply Reel Shaft
@>-1
e--·2
~ -3
®-5
®
~-7
;;;;
.
8
0 .
9-8 @)·-10
@)
@-1
Take-up Reel Shaft
G<>--11
®-- 12
~--13
0 14
® 15
®
: -
" -
e
0
8-----29
8
16
17
--18
Fig. 4
a) Supply Reel Shaft
The tension of the supply reel shaft is 10 g standard
as measured by a stick gauge, provided that the tape
is wound around a 3" reel in the playback condition,
to a thickness
of 40 mm, with the end of the tape
curled
into a ring.
Adjust the tension by increasing or decreasing the
tension
of the mission spring Ci) of the supply reel
shaft.
b) Take-up Reel Shaft
The tension
of the take-up reel shaft is 30 g standard,
measured in an identical manner as the supply reel
shaft.
Adjust the tension
by increasing or decreasing the
tension
of the mission spring ® of the take-up reel
shaft.
(However,
counter belt should be removed for
measurement)

8. ADJUSTMENT OF HEIGHT OF REEL
SHAFT (Refer to Figs. 4 and 5) .
a) Adjustment of height of supply reel shaft
Adjust the thickness
of the height adjustment nylon
washer @ after removing the supply reel shaft,
so
that the height from the surface of the mechanism
chassis to the
top portion of the reel table plate is
32.3 mm in the rewinding condition.
b) Adjustment
of height of take-up reel shaft
Remove the take-up reel shaft and adjust the truck-
ness of the height adjustment nylon washer @ so
that the height from the surface of the mechanism
chassis to the
top portion of the reel table plate is
32.3 mm. Correct vertical looseness of the reel shaft
by tilting the
thrust lever ® .
Supply Reel Shaft
Take-up Reel Shaft
Fig. 5

VIl. AMPLIFIER ADJUSTMENT
1. RECORDING BIAS VOLTAGE
ADJUSTMENT
V.T.V.M
TR501
2$8324
TR502
258324
Connect the V.T.V.M. to point (A) and adjust the
recording bias voltage by turning the V.A.C. in the bias
oscillator circuit until it reads the same voltage stamped
on the back of the head assembly.
2. RECORDING LEVEL ADJUSTMENT
(Fig. 2)
TR203
2SC281
TR204
2SC281
a. Set the Automatic Recording Switch to Manual
position.
b. Connect the V.T.V.M. to point (A).
c. Push the Record Button until it locks and set the
Tape Speed Selector to
7-1 /2".
d. Feed a 1,000 Hz sine wave signal (with 1.5 mV
output level) from an Audio Frequency Oscillator to
the Microphone Input of the X-V.
e. Turn the Volume Control VR-la (lOK-A) until the
output level at point (A) reaches 0.9 V.
f. Turn the Volume VR-201 (20K-B) until the VU
meter indicates "0" VU.
Fig. 1
Note : There
is no erase bias voltage adjustment. Correct
bias voltage is between 40 and 50 V AC.
V.T.V.M
~
00
0
Fig. 2

3. A.G.C. (AUTOMATIC GAIN CONTROL)
ADJUSTMENT (Fig. 3)
TR201
0
SW-2a
IN34A
a. After adjusting the Recording Level as indicated in
step (2) above, feed a 1,000
Hz sine wave signal (with
1.5 mV
output level) from an Audio Frequency
Oscillator to the Microphone Input
of the X-V.
b. Set the Automatic Recording Switch to the AUTO
REC. position and
turn the volume VR-202
(500 ohms) until the
VU meter indicates "0" VU.
4. MAIN AMPLIFIER ADJUSTMENT (Fig. 4)
(Adjustment of D.C. Collector Current for
Power Transistors 2SB-370 with no input
signal)
1.5k
100
a. Disconnect the wire between points (A) and (B) by
using a soldering iron.
b. Connect the D.C. AmpMeter (use one with Milli-Amp
Scale) to points (A) and (B).
5.6k 2SC828
Fig. 3
Caution:
(1) When A.G.C. Switch is set to Automatic Recording
position, the adjustment should be done after 30
seconds while C226 (470 JJ.F) completes the
charging.
(2) When Automatic Recording switch
is "ON", the
power source
is recommended to be "OFF".
33/10
D.C.AMMETER Fig. 4
c. Turn the Volume Control VR-1a back to the
minimum position.
d. Turn the Volume VR-401 (1 K ohms) until the D.C.
AmpMeter shows 6 mA.

5. BATTERY CHARGING CIRCUIT
ADJUSTMENT
2S8 370 X2
IN34A
CHARG 1NG LAMP
250mA
50mA-+--------
--::;...TIME
a. Use a fully charged battery.
b. Connect the D,C. AmpMeter (use one with
Milli-Amp Scale) to between points (a) and (b).
c. Connect the D.C. Volt Meter to points (c) and (d).
d.
Turn the Volume VR-501 (5 ohms) to the middle
position.
e. Turn the Volume VR-502 so that the charging
circuit closes (5
,....., 7 mA) indicated on the
AmpMeter)
as soon as the VoltMeter shows 7.5V.
2$8758 X2
VR501 5..n.
c
6.3V
l
Fig. 5
Fig. 6
7mA
Fig. 7

6. TAPE SPEED ADJUSTMENT
TR3
+
~--~--+-~~--4-----_. __ _. __ ~~----~~~--~------~-r---GV
TR7
a. Connect the Frequency Counter to the Speaker
Output Jack.
b: Playback the test tape (1,000 Hz "0" VU recorded)
at 7-1/2" tape speed and adjust the tape speed by
turning the Volume
VR-1 (SK ohm) until the
Frequency Counter indicates 1,000
Hz.
Fig. B