Adjustment Procedures; Cassette Deck - Grundig K-RCD 110 Serviceanleitung

Einstellvorschriften / Adjustment Procedures

Adjustment Procedures

1. CD-Section
Measuring instruments/equipment: Digital Voltmeter, Frequency counter, Filter (circuit see below), Test CD 5A (part no. 72008-376.00)
Note: Do not turn the variable resistor (laser power adjustment). The laser current is pre-set at the factory.
Adjustment Preparations
1. VCO Connect the Digital Voltmeter to the testpoint "PCK",
ground to "D-GND".
a.) Connect the testpoints "A-GND" - "RF".
b.) Close the CD door.
c.) Function switch: CD
2. E-F Balance Connect the Digital Voltmeter via filter to the testpoint
"TEAO", ground to "VREF".
a.) Load the test CD.
b.) Close the CD door.
c.) Function switch: CD
d.) CD function: Play
e.) Connect the testpoints "T-OFF" - "VDD".
Alignment Schemes
PCK VDD T-OFF
IC307
IC304
Testpoints on the solder side
see CD PCB page 3-9.
IC308 IC302
20
1
C325
VR301
IC301
1
C347
1
C351
VR302
A-GND VREF TEAO D-GND RF
MAIN PCB
SW2 SWITCH R/P
2 - 3
Adjustment Processs
±
Adjust with VR301 to 4.32MHz 10kHz.
±
Adjust with VR302 to 0V 25mV.
CD PCB FILTER
22kΩ
TEAO
+
220µ/10V
220µ/10V
+
VREF
TUNER PCB
CD PCB
Bestückungsseite
L6
Component side
L4
3
TC1
R 8
VR1
L2
R 5
IC1
IFT2
2
IFT3
IC303
D 1
1
IC3
L8
4
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K-RCD 110 Einstellvorschriften / Adjustment Procedures

2. Cassette Deck

Measuring instruments/equipment: Frequency counter, AF-voltmeter, wow and flutter meter,
Fe test cassette 449 (part no. 35079-019.00), torque test cassette 456 (part no. 35079-014.00).
Adjustment
1. Tape speed Connect the frequency counter to the headphone socket.
Insert the test cassette 449,
play 3150Hz.
2. Take-up torque Insert the torque test cassette 456.
on Start Function: Playback-Start.
3. Wow and flutter Connect the wow and flutter meter to the headphone
socket.
Insert test cassette 449,
play 3150Hz.
DIGITAL
4. Head gap angle Connect the AF-voltmeter to the headphone socket.
VOLTMETER
(Azimuth) Insert test cassette 449,
play 8kHz.
GND
5. Bias frequency Connect the frequency counter to TP
Insert a recordable cassette.
Function: Record-Start.
6. Bias voltage Connect the AF-voltmeter via a 1:1000 capacitive voltage
divider to TP 4
Insert a recordable cassette.
Function: Record-Start
3. Tuner
Measuring instruments: Signal generator, sweep generator, oscilloscope, frequency counter.
TC3
Adjustment
TC4
TC2 1. AM Couple in a sweep signal of 455kHz at L4 (ferrite aerial)
IF via a loop aerial.
Oscilloscope to the headphone socket.
L3
Function switch: AM
IFT1
2. AM (MW) Var. capacitor to limit stop: MW f
Oscillator
Couple in a standard signal at L4 (ferrite aerial) via a loop
aerial. (f = 1kHz 30%).
mod
Oscilloscope to the headphone socket.
L1
3. AM (MW) MW 600kHz, MW 1600kHz
Aerial bandpass Couple in a standard signal at L4 (ferrite aerial) via a loop
aerial. (f = 1kHz 30%).
mod
Oscilloscope to the headphone socket.
4. FM Feed in a 10.7MHz sweep signal to TP 1 (FM-ant.).
IF Oscilloscope to output TP 2 (IC2, Pin9).
Function switch: FM
5. FM Var. capacitor to limit stop: FM f
Oscillator Couple in the standard signal to TP 1 (FM-ant. f
1kHz, ∆f = 22.5kHz).
Oscilloscope to the headphone socket.
6. FM FM 90MHz, FM 106MHz
Aerial bandpass Couple in the standard signal to TP 1 (FM-ant. f
1kHz, ∆f = 22.5kHz).
Oscilloscope to the headphone socket.
7. FM Feed in a standard signal of 98MHz, unmodulated to
MPX TP 1 (FM-ant.).
(Stereo) Frequency counter to TP 3 (IC2, Pin15).
Band switch: FM-Stereo
2 - 4
Preparations Adjustment Process
With adjustment control (in the cass.-motor) set the
frequency to 3150Hz
Tape tension on:
Playback-Start = 35 - 65g-cm
Fast Forward = 50 - 120g-cm
Fast Rewind = 50 - 120g-cm
Deviation < 0.35% (aurally compensated). Playback
measuring time ≥ 30 seconds.
With the head adjustment screw 1
set the left and right channel to
maximum level.
The levels of the two channels must
not differ by more than 3dB.
4 (R/P head). The oscillator frequency should be 75kHz
Adjust with L8.
The bias voltage is approx. 15V (measured with a 1:1000
(R/P head). capacitive voltage divider).
Adjust with L8.
Preparations Adjustment Process
Adjust IFT2 to obtain maximum.
526.5kHz, f 1606.5kHz At f (at 526.5kHz) adjust to maximum with L6.
u o u
At f (at 1606.5kHz) adjust to maximum with TC4.
o
Repeat this adjustment.
At 600kHz adjust to maximum with L4.
At 1600kHz adjust to maximum with TC3.
Repeat this adjustment.
With IFT1 and IFT3 adjust to maximum and symmetry.
Repeat this adjustment.
87.5MHz, f 108MHz At f (at 87.5MHz) adjust to maximum with L3.
u o u
= At f (at 108MHz) adjust to maximum with TC2.
mod o
Repeat this adjustment.
At 90MHz adjust to maximum with L2.
= At 106MHz adjust to maximum with TC1.
mod
Repeat this adjustment.
Set the frequency to 76kHz ± 100Hz with VR1.
K-RCD 110
±
0.1%.
1
±
10kHz.
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