Technics RS-B205 Service Manual

Dolby NR circuit
1. Test equipment connection is shown in Fig. 10.
2. Set a normal tape and apply 1kHz signal in record pause mode.
3. Adjust by attenuator so that the output between terminal 7 of
10401 (L-CH) {1C402 (R-CH)} and ground is 12.3mV.
— Dolby B (Encode characteristic) —
4. Set NR switch to “Dolby B” and change the input signal to 1kHz, 5kHz.
5. Check that the output between terminal 21 of C401 (L-CH)
{!C402 (R-CH)} and ground change as specified from the level in NR out mode.
Standard value: 6+ 1.5dB (1kHz), 8+ 1.5dB (5kHz)
— Dolby C (Encode characteristic) —
6. Set NR switch to “Dolby C” and change the input signal to 1kHz, 5kHz.
7. Check that the output between terminal 21 of 1C401 (L-CH) {IC402 (R-CH)} and ground change as specified
from the level in NR out mode.
Standard value: 11.5+1.5dB (1kHz), 8.5+1.5dB (5kHz)
@ RESISTORS AND CAPACITORS
AF oscillator. = ATT
Notes: 1. Part numbers are indicated on most mechanical parts. 3. The unit of resistance is OHM (Q).
Please use this part number for parts order. K=10009, M=1000kQ
2. Important safety notice. 4. The unit of capacitance is MICROFARAD (uF).
Components identified by /\ mark have special charac- P=10%yF.
teristics important for safety. When replacing any of these
components, use only manufacturer’s specified parts.
Numbering System of Resistor Numbering System of Capacitor
Capacitor Type Tolerance
ERD — : Carbon
ERG _ : Metal Oxide
ERC : Solid : Non-polar Electrolytic : : 50V DC : +0.25pF
: Electrolytic : 50V DC : +5%
: Ceramic : 6. : 125V DC : +10%
: Ceramic H : 500V DC : +80%, —20%
: Polyester : : 400V AC : +20%
Area : Polyester
: Polyester
: Liquid electrolyte
double layer
capacitor
: Ceramic
[earn [penne [vow] forme [penne [van
%* [E] All European areas except United Kingdom.
%* [EK] United Kingdom.
%* [EGA] F.R. Germany.
¢ RESISTORS
Ref. No. Part No.
Part No.
R1,2 ERDS2TJ223 22k | R47, 48 ERDS2TJ682 6.8k | R 403, 404 ERDS2TU562 5.6k | R 701 ERDS2TJ562 5.6k
R3,4 R 49, 50 ERDS2TJ272 2.7k | R 405, 406 ERDS2TJ332 3.3k | R702 ERDS2TJ472 4.7k
[EGA] only ERDS2TJ332 3.3k | R51, 52 ERDS2TJ222 2.2k | R 407, 408 ERDS2T102 1k | R 703, 704 ERDS2TJ363 36k
R5,6 ERDS2TJ222 2.2k } R53, 54 ERDS2TJ183 18k | R 409, 410 ERDS2TJ333 R 705 ERDS2TJ472 47k
R7,8 ERDS2TJ473 47k | R55, 56 ERDS2TJ391 390 R 706, 707 ERDS2TJ154 150k
R11, 12 ERDS2TJ102 1k | R57, 58 ERDS2TJ391 390 | R411, 412 ERDS2TJ823 82k | R 708 ERDS2TJ152 1.5k
R17, 18 ERDS2TJ472 4.7K } R61, 62 ERDS2TJ102 1k | R413, 414 ERDS2TJ182 1.8k | R 802 ERDS2TJ473 47k
R 19, 20 ERDS2TJ101 100 | R 63, 64 ERDS2Ty822 8.2k | R415, 416 ERDS2TJ512 5.1k | R 803 ERDS2TJ103 10k
R 23, 24 ERDS2TJ101 100 | R 67, 68 ERDS2TJ390 39 | R 417, 418 ERDS2TJ683 68k
R 25, 26 ERDS2TJ225 2.2M | R69, 70 ERDS2TJ103 10k | R419, 420 ERDS2TJ222 2.2k | R 804 ERDS2TJ683 68k
R2 ERDS2TJ820 R 81, 82 R 421, 422 ERDS2TJ823 82k | R 805, 806 ERDS2TJ103 10k
[EGA] only ERDS2TJ102 1k | R423, 424 ERDS2TJ331 330 | R 807 ERDS2TJ223 22k
R 31, 32 ERDS2TJ564 560k | R 200 ERDS2TJ271 R 425, 426 ERDS2TJ473 47k} R811 ERDS2TJ223 22k
R 33, 34 ERDS2TJ123 12k R 600,601 A ERDS2TJ102 1k | R815, 816 ERDS2TJ103 10k
R 35, 36 ERDS2TJ103 10k | R 201 ERDS2TJ680 68 | R 604, 605 R 818 ERDS2TJ103 10k
R 37, 38 ERDS2TJ102 1k | R 202 ERD2FCG270 27 [EK] only A ERQ14LKR56 0.56 | R 819, 820 ERDS2TJ472 4.7k
R 39, 40 ERDS2TJ103 10k | R 300, 304 ERDS2TJ8R2 8.2 R 900 ERDS2TJ392 39k
R41, 42 ERDS2TJ222 2.2k | R 302, 303 ERDS2TJ683 68k | R 606, 607 R901 ERDS2TJ391 390
R 43, 44 ERDS2TJ153 15k | R 304 ERDS2TJ1RO 1 [EK] only A ERQ14LK2R2 2.2 | R 902
ERDS2TJ273 R 401, 402 ERDS2TJ242 700 ERDS2TJ681 680 [EK] only ERD2FCJ4R7 47
¢ CAPACITORS
Part No. l Value Ref. No. Part No. | Value Ref. No. Part No. Value Ref. No. Part No. Value
ECEA1CU100 10 | C 25, 26 ECEA1HU010 C 39, 40 ECKD1H122KB 0.0012 | C 303 ECKD1H332KB —_—(0.0033
ECKD1H122KB 0.0012 | C 27, 28 ECQB1H682JZ 0.0068 | C 41, 42 ECQB1H562JZ 0.0056 }| C 304 ECEA1CU101 100
ECKDIH681KB = 680p | C 29, 30 ECEA1HU010 C 43, 44 ECEA1HU010 1 | C305 ECQP1393JZ 0.039
ECEAQJU101 100 | C 31, 32 ECQB1H222sZ 0.0022 | C 47, 48 ECEA1CU100 10 | C 401, 402 ECCD1H820K 82p
ECEA1HU2R2 2.2 | C 33, 34 ECQB1H822JZ 0.0082 | C 49, 50 ECKD1H102KB —-0.001 | C 403, 404 ECQB1H472JZ —-0.0047
ECEA1CU100 10 | C 35, 36 ECEA1HU010 C 300, 301 ECFRIE222KAY 0.0022 | C 405, 406 ECEA1CU100 10
ECQB1H472JZ (0.0047 | C 37, 38 ECKD2H331KB — 330p | C 302 ECFD1H682KD _0.0068 | C 407, 408 ECQM1H473JZ —_(0.047

Technics RS-B205 Specifications

General

Brand	Technics
Model	RS-B205
Category	Cassette Player
Language	English