Dokorder 7700 - 2 Service Data; Mechanical; Electrical

2. SERVICE
DATA
2-1 MECHANICAL
Record/Playback System
4 track
2
channel stereophonic
Tape Width
Standard
1/4 inch tape
Reel
Size
7-inch or smaller
Motor
Three
(one
2 speed
PLL
DC servomotor
for capstan, two 6
pole
induction
outer-rotor
type
for
reels)
Head
Three
(1
erase, 1 rbcord, 1
playback)
Tape
Speed
!1
.5o/oat
19
cm/sec
(7-1
l2ipsl
,!1
.5%at
9.5 cm/sec
(3
3/4 ips)
Wow and
Flutter
Playback
(RMS)
0.13o/oat
19 cm/sec
(7
112ipsl
,0.20%
at 9.5 cm/sec
(3-3/4
ips)
Fast
Winding
Time
100 sec
for 7-inch reel
(1800-foot
tape, 60
Hz)
Motor
Torque
Hold-back
tention
(playback)
85
gr 110 gr
(255 t30 g.cm)
Take-up torque
(playback)
150
gr
(450
g.cm)
FFlREW
hold-back
tention
30
gr
(
90
g.cm)
Brake Torque
600
-
800
gr
(1.8
-
2.4
kg.cm)
weight
35
lbs
Dimension
17-314"
(H)
X 16-718"
(W)
X 6 3/4"
(D)
2-2 ELECTRICAL
al
v
Y/
V'
Equalization
Bias
Frequency
Frequency
Response
(Playback
)
Frequency
Response
(Overa
ll
)
One-channel
Recording
Signal
to Noise
Ratio
Crosstalk
Channel
Separation
Bias
Leakage
Erase
Ef{iciency
Distortion
(Overall)
Meter Calibration
lnput
Mic
L ine
DIN
Output
Line
DIN
Circuit Complement
Power Consumption
Power Requirement
Headphone
2mW
8Q
NAB
130 KHz
+1
KHz
.19
cm/sec
(7
l12ipsl
50
-
100
Hz
l!
oa,
1o1
Hz
-
1 5 KHz
13
dB
o
9.5
cm/sec
(3
3/4
ips)
50
Hz
-
7.5 KHz
13
dB
o
1
9
cm/sec
(1-1
12
ips)
Normal
30
Hz
-
20
KHz
t3
dB
(30
-
100
Hz, 15
-
20
KHz
t5
dB)
Special
30
Hz
-
20 KHz
13
dB
(50
-
100
Hz, 15
-
20 KHz
t5
dB)
o
9.5 cm/sec
(3-3/4
ips)
Normal
35
Hz- 12KHz
t3dB
(35
-'1
00
Hz, 1.5- 12
KHz15
dB)
Special
35
Hz
-
12 KHz
13
dB
(35
-
100
Hz,
7.5
-
12
KHz
15
dB)
TOOHzll
dB,
15 KHz+5dB
at 19 cm/sec
(7'1
/2ipsl
500
Hz
11
dB, 7.5
KHz
+5
dB at 9.5 cm/sec
(3-314
ips)
Better
than 50 dB
(Playback)
at
0
dB output
level
Better
than
46 dB
(Overall)
at 0 dB
output
level
Better than
50 dB at
1 KHz
Better
than
40 dB at 1 KHz
Less than
-25
dB
Better
than 65
dB at
1 KHz
Less than
3% at
1
KHz
0
dB
output
level
0 dB
at
IOOHz
0
dB output
level
(P.8.
VR-Max)
-58
dB
10 KO
(load
imPedance)
-20
dB
220 K9
30
mV 80
KQ
OdB
47KQ
260
mV 47 KS)
34 transistors,
29 diodes,
5
lC,2
FET
,2
LED,
1
PUT
75W
U.S.A.
type
117 V
(60
Hz)
Universal
type
100 V,117V,125V,20OV,220V,24O
V
(50/60
Hz)
Specs
are subject
to
change
withor-rt
notice.
v