Teac CX-400 - RECORDING PERFORMANCE; SIGNAL-TO-NOISE RATIO; ERASE EFFICIENCY; REC MUTE FUNCTION

Deck settings:
MONITOR
sw.
—TAPE
DOLBY
NR
sw.
—
OUT
TEAC
test
tapes:
INPUT
sw.
—
LINE
MTT-506:
For
record
test
with
Co(CrO2
)
OUTPUT
cont.
—
Spec.
position
(item
2)
MTT-501:
For
record
test
with
NORMA/
5-3.
RECORDING
PERFORMANCE
RECORD
cont.
—
Spec.
position
(item
8)
METAL:
For
record
test
with
METAL
MEASURING
POINT
ADJUST
INSTRUCTION
_
INPUT
SIGNAL
(or
CHECK)
REMARKS
RESULT
LINE IN BIASTRAPTP
10.
Bias
trap
Record-pause
mode
No
signal
L106/L206
Min.
reading
LINE IN OUTPUT
:
,
BIAS/EQ
—
Co
(Cr0,
)
)
11.
Record
bias
=
5:
2
6.3
kHz/—42
dB
C163/C263
2.5
dB
+1.5
dB
Tape — MTT-506 (6.15 mV) : over-bias
_ ~ | LINE IN
BIAS/EQ
—
Co
(C10,
)
OUTPUT
Tape -MTT-506 Pi acm aaa id —8 dB (308 mV)
IAS/EQ — NORMAL
12.
Record
level
BIAS/EO
TTS
_8
dB
+1
4B
(275 mV~346 mV)
BIAS/EQ — METAL
Tape — METAL
LINE IN :
BIAS/EQ — METAL 400 Hz/—12 dB OUTPUT
Tape
—
METAL
(195
mV)
2.2%
or
less
13.
Total
harmonic
BIAS/EQ
—
Co
(CrO,)
.
distortion
Tape
—
MTT-506
BIAS/EQ
—
NORMAL
Tape
—
MTT-501
2.5%
or
less
OUTPUT
BIAS/EQ
—
Co
(C10,
)
LINE
IN
40H
+4;
—4
dB
(
Tape
—
MTT-506
Required
signal/
~
ea
Soe
742.4B
(6.15
mV)
_
|}1103/L203
|
133232)
-2
68
BIAS/EQ
—
NORMAL
‘|
400Hz
04dB
(Ref.)
14.
Frequency
Tape
—
MTTS01
response
we
ee
ee
ee
te
BIASIEQ-METAL
|
»
|aqapsnong
Lee
|
Tape
—
METAL
1104/1204
10kHz +3, -4 4B
If frequency response is wrong, recheck steps 11 and 13.
BIAS/EQ
—
METAL
OUTPUT
gt
Tape
—
METAL
LINE
IN
44
dB
min.
ratio
15.
Signal-to-noise
BIAS/EQ
—
Co
(CrO,)
1
iia
—9
dB
(275
mV)
an
sie
of
spec.
ratio
Ue
ge
a
no
signal
ee
‘to
noise
BIAS/EQ
—
NORMAL
a
Tape
—
MTT-501
43
dB min.
ratio
® Connection — Fig. 5-1. But switch ON 1 kHz filter.
e Record 1 kHz. Rewind tape to mid point of recorded portion. Do “no signal”
recording. Get difference between 1 kHz portion and its erased portion.
16. Erase efficiency
LINE IN Ref, output
: | 1kHz/+1 dBo : level:
BIAS/EQ — METAL (0.869V) OUTPUT
65 dB min. ratio
+5 dB
Tape
~
METAL
(1.38V)
no signal
e Connection — Fig. 5-1. But switch ON 1 kHz filter.
e Record 1 kHz. Then push REC MUTE button for several sec, Rewind and
play tape. Get difference between 1 kHz portion and the “no signal” portion.
17.
REC
MUTE
nN
:
function
:
Teva
an
Ref.
output
~
BIAS/EQ
—
METAL
(0.869V)
OUTPUT
-
|
level:
(
Tape
—
METAL
:
,
65
dB
min.
ratio
+5
dB
no signal . (1.38V)
10