Technics RS-B14 User Manual

@ Overall frequency Condition: Equipment:
response
*
Record/playback
mode
*
VTVM
*
Test
tape
*
Normal
tape
mode
*
ATT
(reference
blank
tape)
e
CrO,
tape
mode
*
AF
oscillator
...
QZZCRA
for
Normal
*
Metal
tape
mode
*
Oscilloscope
...QZZCRX
for
CrO,
* Input level controls... MAX • Resistor (6009) ...QZZCRZ for Metal
Note:
Before measuring and adjusting, the overall frequency
response make sure of the playback frequency response (For
the method of measurement, please refer to the playback fre-
quency response).
Overall frequency response chart (Normal)
(Recording equalizer is fixed)
1. Make connections as shown in fig. 11.
2. Place UNIT into normal tape mode and insert the normal
reference
blank
test
tape
(QZZCRA).
SO
үм
Жш
5ш
кш
Ж
We
100?
3. Supply а 1kHz signal from the AF oscillator through ATT to
LINE
IN.
-
i
K
4. Adjust АТТ so that input level is -20dB below standard Р | i
5
recording level (standard recording level =0 VU).
. Adjust the AF oscillator frequency to 1kHz, 50Hz, 100Hz,
200 Hz, 500Hz, 4kHz, 8kHz and 10kHz signals, and record ув? (L-CH) |
these signals on the test tape. VRB (R-CH) 0 lj
. Playback the signals recorded in step 5, and check if the = Ó
frequency response curve is within the limits shown in the
overall frequency response chart for normal tapes (fig. 10).
(If the curve is within the charted specifications, proceed to
steps 7, 8 and 9.)
If the curve is not within the charted specifications, adjust p ella Утум. pM d
as follows; v б For overal frequency
VTVM Oscilloscope response measurement
For bias voltage
measurement
Fig. 11
Adjustment (A): Adjustment (B): b
When the curve exceeds the TD When the curve falis below
overall specified frequency : Le the overall specified fre-
response chart (fig. 10) as Hi quency response chart (fig.
shown in fig. 12. == ® 10) as shown in fig. 13.
1) Increase bias current by = р | 1) Reduce bias current by
turning VR7 (L-CH) and turning VR7 (L-CH) and ==
VR8 (R-CH). 7 УВВ (R-CH). а ЕЗИ
(See fig. 1 оп page 6.) pe QUK Repeat steps 5 and 6 for EE WM
2) Repeat steps 5 and 6 for SkHz 7kHz 8kHz confirmation (Proceed to 6 kHz 7ана ван:
confirmation (Proceed to Fig. 12 steps 7, 8 and 9 if the Fig. 13
steps 7, 8 and 9 if the curve is now within the | ;
curve is now within the charted specifications (
charted specifications as shown fig. 10.) as shown fig. 10.)
3) If the curve still exceeds the specifications (fig. If the curve still falls below the charted specifica-
10), increase bias current further and repeat tions (fig. 10), reduce bias current further and
steps 5 and 6. repeat steps 5 and 6.
7. Place UNIT into CrO, tape mode.
8. Change test tape to CrO, reference blank test tape} Overall frequency response chart (CrO,, Metal)
(QZZCRX), and record 1kHz, 50Hz, 100Hz, 200Hz, 500Hz,
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 CrO, tapes (fig.
14).
. Place UNIT into metal tape mode and change test tape to
metal reference blank test tape (QZZCRZ), and record
1kHz, 50Hz, 100 Hz, 200Hz, 500Hz, 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 metal tapes (fig. 14).
. Confirm that bias voltage are approximately as follows
when the UNIT is set at different tape mode.
* Measure the voltage across the head using a VTVM.
50H: 100H2 2008: 500Hz ]KHz 2кн2 ані
around 6.2V (Normal position)
Reference value: around 8.9V (CrO, position)
around 15.7V (Metal position)

Technics RS-B14 Specifications

General

Brand	Technics
Model	RS-B14
Category	Cassette Player
Language	English