Technics RS-M215

RS-M215
Equipment:
*VTVM * AF oscillator
* ATT * Oscilloscope
* Resistor (600 Q)
* Test tape
(reference blank tape)
+-+-QZZCRA for Normal
-+-QZZCRX for CrO2
--+QZZCRZ for Metal
MEASUREMENT & ADJUSTMENT
*
eae
This
chart
indicates
the
standard
values
for
the
new
type
of
QZZCRA
when
in
use.
*
eo)
This
chart
indicates
the
standard
values
for
the
former
type
of
QZZCRA
when
in
use.
—
The new type of QZZCRA is marked as shown in fig. 13.
New type
Qs
ZZCRAS
Former type
Overall
frequency
response
adjustment
by
recording
bias
current
Note 1:
On RS-M215, overall frequency response
is adjusted with tape selector set at Normal.
Note 2: <>}
6000, -
gs [O00]
ATT AF oscillator
eae (L-CH)
Record/playback fai
LINE IN
Recording equalizer is fixed. TP (L-CH)
the TP2(R-CH) Playback/ LIne UT
1. Make connections as shown in fig 14. R1 (L-CH) [= record mode
2. Input a 1kHz, —24 dB signal through R2 ne
roun
LINE IN. Place the set in record
mode.
3. Fine adjust the attenuator to obtain
0.4V LINE OUT output.
* Make sure that the input signal level
is —24+4dB with 0.4 V output
voltage.
. Set the tape selector to Normal, and load the test tape (QZZCRA).
. Adjust the attenuator to reduce the input signal level by 20 dB.
.
Adjust
the
AF
oscillator
to
generate
50Hz,
100Hz,
200Hz,
500Hz,
1
kHz,
4kHz,
8kHz
and
10kHz
signals,
and
record
these
signals
on
the
test
tape.
7,
Playback
the
signals
recorded
in
step
6,
and
check
if
the
frequency
response
curve
is
within
the
limits
shown in the overall frequency response chart for normal tapes (tig. 12).
(If
the
curve
is
within
the
charted
specifications,
proceed
to
steps
8,
9
and
10.)
If
the
curve
is
not
within
the
charted
specifications,
adjust
as
follows:
Adjustment @): Adjustment ®):
When
the
curve
exceeds
the
overall
frequency
When
the
curve
falls
below
the
overall
frequency
response
chart
specifications
(fig.
12)
as
shown
response
chart
specifications
(tig.
12)
as
shown
in fig. 15. in fig. 16.
VIVM os cilloscope
For overall frequency
response measurement.
3
VIVM oscilloscope
For bias current measurement.
Fig. 14
ome
== -b-----~ $-----~ +
2kHz 4kHz 8kHz
1) Reduce bias current by turning VR101 (L-CH)
and VR102 (R-CH).
2) Repeat steps 6 and 7 to confirm.
(Proceed to steps 8, 9 and 10 if the curve is
now within the charted specifications in fig.
12)
3) If the curve still falls below the charted
specifications (fig. 12), reduce bias current
further and repeat steps 6 and 7.
1) Increase bias current by turning VR101
(L-CH) and VR102 (R-CH).
(See fig. 2 on page 3.)
2) Repeat steps 6 and 7 to confirm.
(Proceed to steps 8, 9 and 10 if the curve
is now within the charted specifications in
fig. 12.)
3) If the curve still exceeds the specitications
(fig. 12), increase bias current further and
repeat steps 6 and 7.
8.
Switch
the
tape
selector
to
CrOz,
change
test
tape
to
QZZCRX,
and
record
50
Hz,
100
Hz,
200
Hz,
500Hz,
1
kHz,
4kHz,
8kHz,
10kHz
and
12.5kHz
signals.
Then,
playback
the
signals
and
check
if
the
curve
is
within
the
limits
shown
in
the
overall
frequency
response
chart
for
CrOz
0”B
tapes
(fig.
17).
Overall frequency response chart (CrOz, Metal)
100HZ 200Hz —_500Hz
4 Shaan poe