Technics RS-M7 Service Manual

ITEM MEASUREMENT & ADJUSTMENT
Overall gain
Condition:
« Record/playback mode
* Input level control --- MAX
* Standard input level;
MIC «+s eee —72+£3dB
LINE IN--- —24+3dB
Equipment:
* AF oscillator «VTVM
« Oscilloscope * ATT
« Test tape
(reference blank tape)
---QZ7ZCRA for Normal
Level meter
Condition:
* Record mode
* Input level control --- MAX
Equipment:
*VTVM_ * Oscilloscope
* AF oscillator * ATT
Overall frequency response
Condition:
* Record/playback mode
* Input level control --- MAX
Equipment:
* VTVM
* AF oscillator
* ATT
* Test tape
(reference blank tape)
--- QZZCRA for Normal
--+ QZZCRX for CrOz
--- Q7ZCRY for Fe-Cr
. Adjust ATT until monitor level at LINE OUT becomes 0.39 V. LINE IN
. Using test tape, make recording.
. Playback recorded tape, and make sure the value at LINE OUT
_ lf measured value is not 0.39 V, adjust VR5 (L-CH), VR6
_ Adjust ATT so that the monitor level at LINE OUT becomes
. Adjust VR501 (L-CH) and VR502 (R-CH) so that the level
. Test equipment connection is
. Load reference blank test tape and
. Playback and express in dB the
. Test equipment connection is shown in fig. 14.
. Place UNIT into record mode, and tape selector to normal
position.
. Supply 1 kHz signal (—24 dB) from AF oscillator, through ATT,
to LINE IN.
AF oscillator Record mode
Test tape
R/P head LINE OUT
on VIVM becomes 0.39 V.
Playback mode yTVM Oscilloscope
Fig. 14
Test tape
(R-CH) (See fig. 21 on page 5).
. Repeat from step (2).
_ Test equipment connection is shown in fig. 15. LINE OUT
. Supply 1kHz signal from the AF oscillator, through the ATT,
to the LINE IN jack.
AF oscatator
0.39V
Fig.
15
meters indicate O dB.
Overall frequency response chart (Normal)
shown
in
fig.
14.
am
14+
d8
place UNIT into record mode. Pas +368
. Supply 1kHz signal from AF
oscillator through ATT to LINE IN.
. Adjust ATT so that input level is
— 20dB below standard recording
level (standard recording level
—24
dB).
Fig.
16
. Record each frequency 50 Hz,
100Hz, 200Hz, 1kHz, 2 kHz, Overall frequency response chart (Fe-Cr)
4kHz, 8kHz and 10kHz (12kHz a ee
for CrOz and Fe-Cr tape) at the | ew
same level.
+ 3.508
difference between playback
output level of each frequency
based on playback output level of
808
2kHE WH? oo
1 kHz.
. Make sure that the measured value
is within the range specified in the
overall frequency response chart.
. Set the tape selector to CrOz,
Fe-Cr position.
. Measure as same as manner
above.
. Make sure that the measured value
is within the range specified in the
overall frequency response chart
for CrOQ2 and Fe-Cr tape shown in
fig. 17 and 18.
Overall frequency response ; Adjustment 1—Using bias current
adjustment
(As a standard for adjustment)
12hH2
Fig. 17
Overall frequency response chart (CrO2)
2kHz AH?
; {
1. When the frequency response between the middle and high-
frequency range becomes higher than the standard value, as
shown by the solid line in fig. 19, increase the bias current by
turning L5 (L-CH), L6 (R-CH).
2. When it becomes lower, as shown by dotted line, reduce the
bias current by turning L5 (L-CH), L6 (R-CH).
dame baw iQenm; | bare
Fig. 19

Technics RS-M7 Specifications

General

Brand	Technics
Model	RS-M7
Category	Cassette Player
Language	English