Technics RS-M04 Service Manual

11
ITEM MEASUREMENT & ADJUSTMENT
© Overall gain 1. Test equipment connection is shown in fig. 38.
Condition: 2. Place UNIT into record mode, and normal tape mode.
* Record/playback mode 3. Supply 1 kHz signal (—24dB) from AF oscillator, through ATT to LINE IN.
* Normal tape mode 4. Adjust ATT until monitor level at LINE OUT becomes 0.7 V.
* Input level controls ---- MAX | 9: Using test tape, make vecording.
*
Output
level
control
---
MAX
6.
Playback
recorded
tape,
and
make
sure
the
value
at
LINE
OUT
on
VTVM
becomes
0.7
V.
* Standard input level 7. If measured value is not 0.7 V, adjust VR5 (L-CH), VR6 (R-CH) (See fig. 23).
MIC verre —72+35dB | 8. Repeat from step 2.
LINE IN-+- ~2443.5dB
Equipment:
* VTVM__ * AF oscillator
* ATT * Oscilloscope
* Resistor (6002)
* Test tape
(reference blank tape)
+» QZZCRA for Normal
+
© Fluorescent meter . Test equipment connection is shown in fig. 38.
Condition: 2. As shown in fig. 43, connecting the base of Q302
* Record mode (Point ©, see fig. 23 on page 6) and ground stops
* input level controls --+- the oscillation of the astable multivibrator comprising
* Output level control +: Q302 and Q303.
Equi
;
3.
Supply
1
kHz
signal
(—
24
dB)
to
the
LINE
IN
jack,
quipment :
* VTVM then press the record button.
+ ATT 4. Adjust the ATT so that the output level at LINE OUT
jack becomes 0.7 V (The input level at this condition
is termed the standard input level).
5. Adjustment at “—20dB”.
A. Adjust the ATT so that input level is —20dB Fig. 43
below standard recording level.
B. Adjust VR301 so that the —20dB segment lights up in the —20dB+0.8dB range (L-CH ONLY)
(See fig. 44).
6. Adjustment at “OdB" >
MAX
MAX
* AF oscillator
* Resistor (600)
Q302 Q303
A. Adjust the ATT so that the output Wa
level
at
LINE
OUT
jack
becomes
CSUN
TTT
TTT
TTT
ECT
0.7V.
20
(PAK)
6°
4*2+0+2
00-638:
(The input level at this condition is Fig. 44
termed the standard input level.)
B.
Adjust
VR302
so
that
the
+
1B
A
RTT
a
mee
segment
lights
up
in
the
0
+0.2
dB
L
SHATETTTTT
TTT
ET
ETT
range
of
the
standard
input
level
PISEUAUSEES
EN
SEYSES
(See
fig.
45).
20:
[PEAK]!
“Gas
2929
"10;
ie,
2
IEI"S6
18°
7. Repeat twice between steps 5 and 6 Fig. 45
above. 6 ea UL
8. Adjust ATT and check that all RVIIUPINPIVELYELITIETLYEISY EVENT TE YT WYIVYIYELSEAT LOY)
segments light up when an input signal L SATYUNNTTIUTTUILICUUEPEUULTEUT CET EETT PET TTT T TT
level
is
increased
to
10dB
higher
than
3b
RAE
Bae
A
we
ae
OO
«6
&
ae
the
standard
input
level
(See
fig.
46).
Fig.
46
@ Dolby NR circuit
Condition:
* Record mode
. Place UNIT into record mode, set the Dolby NR
switch to OUT position and supply to LINE IN to
obtain —34.5dB at TP5 (LECH), TP6 (R-CH)
TPS (L-CH)
1C1 (L-CH)
HC2 (R- cH) TP6 (R-CH)
[eo
*
Input
level
controls
----
MAX
(frequency
5kHz).
ee
|
Eau 2. Confirm that the value at IN position is 8 (+2.5) Xe ©y
quipment: : dB greater than the value at OUT position of AF oscillator == ATT Record mode = VTVM
* VTVM — * AF oscillator Dolby NR switch .
*ATT — * Oscilloscope Fig. 47
* Resistor (600Q)

Technics RS-M04 Specifications

General

Brand	Technics
Model	RS-M04
Category	Cassette Player
Language	English