Harman kardon ch 140 service manual

Page 2

SPECIFICATIONS
0 FM SECTION Nominal Limit

Tuning Range 87.5MH2~IO7.9MHZ
Usable Sensitivity IZdBf s ISdBf
Quieting Sensitivity

Mono 17dBf s 23dBf

Stereo 35dBf S 40dBf
Signal to Noise Ratio

Mono 72dB 2 66dB

Stereo 65dB 2 60dB
IF Rejection (88.1MHz) 100dB z 90dB
Image Rejection (98.1MHz) GOdB 2 55dB
AM Suppression 50dB 2 44dB
Capture Ratio 15:13 5 3dB
Selectivity (t400kHz) 70dB 2 60dB
Distortion (Stereo)

(65dBf,100%l 0.22% s 0.4%
Frequency Response

(+0, -3dB) 20Hz~15kHz
MPX Separation at 1kHz 44dB 2 35dB
Output Level (75kHz dev.) 775mV 23dB

0 AM SECTION

Tuning Range 530kHz~1620kHz

Signal to Noise Ratio 50dB 2 45dB
lF Rejection (600kH2) lOOdB 2 90dB
Image Rejection (1400kHz) 55dB 2 50dB
Selectivity (tSkHz) 50dB 2 45dB

.AUDIO SECTION Nominal Limit
Tone Control Action
Bass (50Hz) lldB :kl.5dB
Treble (10kHz) 11dB 11.5dB
Output Impedance 5000
O CASSETTE TAPE DECK SECTION
Wow and Flutter 0.1% s 0.2%
Tape Speed (4.759m/seC.) +1% 5 +3% -1%
FF and REW Time
(for C-GO tape) 125sec. s 1505ec.
Signal to Noise Ratio (LN Position)
DolbyI NR Off 55dB 2 50dB
Dolby NR On 64dB z 58dB
Distortion 1% s 2%
Frequency Response 20Hz~ 20kHz
Separation 40dB 2 35dB
Crosstalk 70dB 2 60dB

Output Level (Volume Max.) 610mV thB

This specification is the target of servicing. But. there is a case that
the specification is not applicable to the measurement condition and
instrument.

Specifications and components subject to change without notice. Overall
performance will be maintained or improved.

*Dolby noise reduction manufactured under License from Dolby
Laboratories Licensing Corporation. Dolby" and the double-D
symbol are trademarks of Dolby Laboratories Licensing Corporation.

DISASSEMBLY PROCEDURES (REFER TO PAGES 10 AND 13)

(E CASSETTE TAPE PLAYER MECHANICAL ASSEMBLY
(104) REMOVAL
Remove 4 screws 0 and then remove the Bracket (173).

. Pull out the Fader Knob (158).

. Remove 4 screws 6 and then remove the Center Panel
Assembly (101).

. Remove 4 screws 0 and then remove the Cassette Tape
Player Mechanical Assembly (104) with the NAB AMP,
MSS/Mecha Control and Dolby P.C. Boards (PCB-2,
PCBAB and PCB-9) and the Brackets (171 and 168). Also,
disconnect the lead wires connected to the Main P.C.
Board (PCB-1).

. Disconnect the lead wires connected to the Dolby P.C.
Board (PCB-9).

. Remove 2 screws 0 and then remove the Dolby P.C.
Board (PCB-9).

. Disconnect the lead wires connected to the NAB AMP
RC. Board (PCB-2).

. Remove 2 screws 0 and then remove the NAB AMP
P.C. Board (PCB-2).

b unr-

macaw

9. Disconnect the lead wires connected to the
MSS/Mecha control P.C. Board (PCB-3).

10. Remove the screw 0 and then remove the MSS/Mecha
control PC. Board (PCB-3).

11. Remove 4 screws (3 and then remove the Cassette
Tape Player Mechanical Assembly (104) from the
Bracket (171).

(2) MAIN PC. BOARD (PCB-1) REMOVAL
1. Remove 4 screws 0 and then remove the Bracket (177)
and the Insulator (183).

. Remove the Center Panel Assembly (101). (Refer to step
E2 and 3.)

. Pull out 9 Push Buttons (153).

. Remove the screw 0 and then remove the Bracket
(169).

. Remove 6 screws 0 and then remove the Main P.C.
Board (PCB-1) with the Buffer AMP P.C. Board (PCB-4).
Also, disconnect the lead wires connected to the Main
RC. Board (PCB-1).

meters:

ALIGNMENT PROCEDURES (REFER TO PAGES 7~12)

I ELECTRICAL ADJUSTMENT

1. Before adjustment

0 Connect a 14V power supply to the Power Supply
Lead (+ACC, +8 and GND).

0 Since head magnetization, dust accumulations, etc.
are likely to introduce errors in the various
characteristics, it is very important that the heads are
properly demag-netized and cleaned before commen-
cing any adjustment, particularly frequency response
and head azimuth adjustment.

2. Instruments required

0 Low frequency oscillator

0 AC VTVM or dual channel AC VTVM
O Oscilloscope

O Wow/flutter meter

0 Frequency counter

3. Test tapes
0 Dolby NR level adjustment
0 Azimuth adjustment

MTT~ISO or TCC7130
TCC7153

,a