Teac A-550RX Service Manual page 11

A-SSORX
ITEM
CONNECTION
ADJUST
{or CHECK)
MODE/
INSTRUCTION
SIGNAL
SOURCE
OUTPUT
REMARKS
19. Signal-to-
noise ratio
Fig. 5—2
1 kHz/-9 dB
{275 mV)
then
no signal record.
Spec. REC cond.
METAL/METAL \
J Co(CrO2)/MTT-506
| NORMAL/MTT-501
Check
48 dB min. ratio
46 dB min. ratio
+
Ratio of spec.
output —5 dB
to noise
Erase effi-
ciency
20.
Fig. 5-2
Switch on 1 kHz
filter
Spec. REC cond.
METAL/METAL
(or Co(CrO2)/ MTT-506}
® Record 1 kHz. Re-
wind tape to mid
point of recorded
portion. Do no
signal recording.
Get difference be-
tween 1 kHz por-
tion and its
erased portion.
L
1 kHz/+1 dB
(0.869 V)
then
no signal record,
Check
65 dB min. ratio
21. REC MUTE
function
Fig. 5-2
Switch on
1 kHz filter
Spec. REC cond.
METAL/METAL
(or Co(CrO2)/ MTT-506)
@ Record 1 kHz. Then
push REC MUTE
button for several
sec. Rewind and play
tape. Get difference
between 1 kHz portion
and the created no
signal portion
1 kHz/+1 dB
(0.869V)
then
no signal record.
Check
65 dB min. ratio
22. Channel
separation
Fig. 5-2
But use LINE
IN (L)only as
input, switch
on 1kHz filter
a
Spec. REC cond.
METAL/METAL
(or Co(CrO2)/MTT-506)
@ Set deck in record
mode. Find diffe-
rences between 1 kHz
recorded portion
(L-ch) and no signal
portion (R-ch).
1 kHz/—9 dB
(275 mV) paeek
30 dB min. ratio
23. Adjacent
track
crosstalk
Fig. 5-2
But use LINE
IN(R) only as
input, and
OUTPUT(R)
only as output
—- +
Spec. REC cond.
METAL/METAL
(or Co(CrO2)/MTT-506)
® Record 125 kHz on
R-ch. Note output
level of its recorded
portion. Invert tape
and play R-ch track.
Check leakage level
against the output
ref. of previously
recorded portion.
125Hz/—9dB
(275 mV) jeneck
40 dB min. ratio
24. Dolby NR
effect
Fig. 5-2
Spec. REC cond. [
METAL/METAL
(or Co(CrO2)/MTT-506)
®@ Record 1 kHz w/
NR SYSTEM sw. to
OUT. Play its portion
w/ sw., OUT and
DOLBY. Get the
output level diffe-
rence between OUT
and DOLBY
10 kHz/—39
dB (8,69 mV)
1 kHz/—29
dB (27.5 mv) (Check
®@ Repeat the above
process for 10 kHz
Variation
5.5 dB +2.5dB
Variation
10 dB +2 dB
11