Grundig RPC 200/a Serviceanleitung Seite 4

h) Frequency response
Measuring frequency 40 Hz, I kHz, 12.5 kHz, 16 kHz
Maximum deviation from "linear" ± I .5 dB
The position of the tone controls for linear frequency
response must not be more than 100 from the middle.
i) TA-magnetic equalisation
Select TA-magnetic
Set frequency response linear
Reference frequency 1kHz OdB
Tolerance ± 2 dB
f 40 Hz 250 Hz 1 kHz 4 kHz 16 kHz
dB +16.5dB +5.5 dB OdB —6 dB -17 dB
Do not overdrive amplifier input/output
k) AF control range
Reference frequency: I kHz A O dB Tolerance
-18 dB ± 2 dB
Bass control: 40 Hz+13
Treble control: 16 kHz +15.5-18 dB ± 2 dB
Balance control: 1 kHz+ 2 -8.5 dB ± 1 dB
l) Loudness compensation
Set volume control to —40 dB
"Contour" on I kHz O dB
40 Hz: lift +19 dB ± 2dB
12.5 kHz: lift + 8dB ± 2dB
Do not overdrive output amplifier!
m) Channel deviations
Check operation of the volume control in the range 250 to
6.3 kHz S 2 dB, starting from 300 Of the lower Stop.
"Contour" on, otherwise as paragraph m)
Channel balance 3 dB
Channel balance of the bass control at 250 Hz S 2 dB
Channel balance of the treble control at 6.3 kHz S 2 dB
n) Signal to noise ratio (unweighted)
I. TA input:
Measuring method according to DIN 45 405, AF-voItmeter
with peak value indicator and bandpass filter 31.5—20 kHz.
Receiver to TA. Set switch and tone control to "linear".
With reference to 2 x 24 W on 4 Q
Measuring frequency 1 kHz 5 mV
Load the sockets with 2 x 2.2 kQ
Adjust volume control for 2 x 24 W 9.8 V on 4 Q
Signal to noise ratio 62 dB.
With reference to 2 x 50 mw on 4 Q
Adjust volume control for 2 x 50 mw A 0.446 V on 4 Q
Signal to noise ratio 55 dB
2. TB input:
Select TB
With reference to 2 x 24 W on 4 Q
Measuring frequency 1 kHz 0.5 Vr„s
Loadthe socketswith 2 x 47 kQ i i 250 pF
Adjust volume control for 2 x 24 W A 9.8 V on 4 Q
Signal to noise ratio 76 dB.
With reference to 2 x 50 mw on 4 Q
Adjust volume control for 2 x 50 mw A 0.446 V on 4 Q
Signal to noise ratio 55 dB
o) Cross talk TB
Volume control to maximum, set "linear" frequency
response, balance control to middle position.
I oad TB-input(notdriven) with 47 kQ II 250 pF
Measuring frequencies 250 Hz 1kHz I O kHz
Z58dB 252dB æ36dB
p) Testing stability
Do not load loudspeaker outputs, connect oscilloscope to
loudspeaker outputs. Feed in 40 Hz via TB. If the output
voltage isunstable this is seen on the oscilloscope.
q) TB-recording
Select TA and switch to stereo
Volume control to minimum, drive via TA input with I kHz,
Output voltage on the TB-socket, on points 1/2 (left) and
points 42 (right) loaded with 47 kQ 250 pF must be 19 mV
± 2 dB
r) Checking the headphone socket
Adjust output voltage on LS-socket loaded with 4 Q for
4 Vrms.Without loading the headphone sockets 2.4 V
± 10 % must be obtained between points 4/3 and 5/2.
Checking operation of the record player Dual 1236 G 11236 A
( RPC 200/a only)
Check with unit build in.
a) Mechanical: Start—stop, automatic shutoff, speed se-
lector, record changing, antiskating, pitch-control, tone
arm lifting, descending point, and stylus pressure ad-
justing.
b) Electrical: By means Of a stereo test record with left-
right-signal test for overall performance.
Checking operation of the cassette recorder CB 210
(RPC 200 and RC 200 only)
Check with unit build in.
a) Mechanical: Start—stop, pause, forward, rewind, auto-
matic end of tape stop, opening of the cassette com-
partment.
Electrical: Record, playback, (right-left-identification)
b)
oscillator switch, tape type selector switch, variable
fade in/out when recording.
s) Checking the active 5 kHz-fiIter
All programme buttons released
Feed in i I R 1093 (12 kQ) approx. 100 mVrms
(RWI S 200 Q). Measure on the LS-sockets on 4 Q.
Switch and tone controls "linear"
Reference frequency I kHz OdB
Measuring frequency 2.5 kHz +2.5 dB
Measuring frequency 5 kHz —12.5 dB
t) Active 19 kHz-filter, pilot attenuation
Depress UKW (FM) button, touch sensor Stereo on.
FM-generator with ± 40 kHz deviation frnod1kHz, plus
± 7.5 kHz pilot deviation.
Signal level I mV/240 Q
Load LS-sockets with 4 Q, set switch and tone controls to
"linear". Adjust volume for 2.25 W 3 V on 4 Q
Reference level 1 kHz O dB, 19 kHz -30 dB, 38 kHz
-45 dB.
IV. Adjustment Of tuning voltage
Switch on UKW (FM) and sensor "U"
AFC "off"
Digital voltmeter to M 2
Rotary capacitor open
Adjust voltage U, with R 1107 to 30 V ± 100 mV
Rotary capacitor closed
Adjust voltage IJ2with R 5001 to 2.7 V ± 50 mV (note meter
errors)
V. FM-RF-lF-alignment
For this a pre-aligned mixer stage and IF-circuit is needed.
Feed generator symmetrically into aerial sockets (240 Q).
High-resistancevoltmeter for mid-scale indication (UV 5) to
points V andV. Switch wobbulator to ± 400kHzdeviation.
Connect scope withAF-probe v ia47kQto pointV . Switch
set to UKW(FM) and sensor"U". AFC and mutingoff.
Scale pointer to 106 MHz
Wobbulator to 106 MHz mid-frequency.
Adjust IF-curvewith osc.-trimmer @ to middle. Nowalign
circuits O, @and@for maximum andsymmetry. If neces-
sary, adjust IF-curve with osc.-trimmer@ to middle again.
AdjustaerialcircuittrimmerC) and intermediatecircuittrimmer
to maximum.
Core positions: Inner maximum c
Outermaximumd and@
Demodulator alignment
Wobbulator to 106 MHz mid-frequency, however with 70 kHz
deviation, = 200 gV.
Adjust c ircuit @ for AF-maximum andcircuit @ forzero
passage, repeat alternately.
Core positions: Inner maximum
Scale pointer to 88 MHz
Wobbulator to 88 MHz mid-frequency.
AdjustUV5for mid-scalezero indicationwith oscillatorcoreO.
Nowalignaerialcircuit@and intermediate c ircuitO formaxi-
mum. Repeat oscillator and RF-circuit alignment alternating
until no improvement is possible ending with 106 MHz.
Core positions: Inner maximum
VI. Alignment of the field strength meter (FM)
Generator with ± 40 kHz deviation (fmod= 1 kHz) to earial
socket. Ue mV on 240 Q f = 106 MHz. Adjust pointer of
meterto '10' using R 1031. At OYV (max. 0.1 N) generator
output voltage on 240 Q adjust for "O" pointer reading with
R 1045.
One adjustment affects the other, therefore repeat adjustment
if necessary.
VII. Stereo decoder alignment
For alignment the following measuring instruments are needed,
stereo-coder SC 5, oscilloscope G 10/13 or similar with probe
TK8/9 (RE 10 MO), low-pass filterfg 15 kHz, AF-voltmeter
MV 5 or similar. Receiver to VHF, stereo. 4 Q load resistors on
the LS-sockets. Volume control to first tap, set amplifier for
linear frequency response. Signal level 200 gV/240 Q, align
receiver accurately, AFC "on".
a) Alignment of the 19 kHz-circuit 09223-647.22 @ and
09223-648.22g
Scope withprobe 10:1 to point V . Modulate s ignal w ith
19 kHz pilot, 10% pilot deviation 7.5 kHz deviation).
Alignment@and@for maximumoscillogramheight.
Core positions: Outer maximum
b) Alignment of the 38 kHz-circuit 09223-649.220
Scope withprobe10: I to point V . Signal s ameasforVIIa).
AlignmentO for maximum oscillogramheight.
Core position: Outer maximum
VIII. AM-IF alignment
The alignment should be carried out with smallest possible
voltage. Wobbulator tov. Scope to
The middle frequency is determined by the ceramic filter. Align
circuits (j) and@for maximum andsymmetry.
Core positions: Outer maximum.
IX. AM-oscillator and input circuit alignment
Range
Sensitiv-
Frequency Input ity
Pointer Pos.
160 kHz @Max. @Max. 8
LW
290 kHz Max. 16
560 kHz O Max. @Max.
14
@Max.
1450 kHz Max. 23
@Max. @Max.
6.1 MHz 10
@Max. O Max.
15MHz 14
X. Alignment of the tuning meter (AM)
At approx. 1 MHz and 500 mV generator output voltage (fmod
1 kHz 30%), adjust R 1034 so that the pointer of the meter is
over the marking point near "8.5". At 30 PV RF-voitage adjust
R 1038 so that the pointer is over the mark near "I One
adjustment affects the Other, therefore repeat alignment if
necessary.
Alignment of the sideband-circuit 09223-650.22@
c)
Scope withprobe10:I to point V. Generator modulated
with 0.1 kHz. Align @ for maximumamplitude and sharp
cut-off points. "S" (R —L), pilot off.
Core position: Outer maximum
d) Pilot phase alignment
Connect AF-voltmeter to the left hand channel loudspeaker
socket via a low pass filter fg = 15 kHz. Generator: Modu-
lated with 1 kHz "S", pilot on (10% deviation) stereo light
must light up, otherwise adjust with R 1101 and R 1033 for
higher sensitivity.
With@adjust for maximum AFoutput.
Stereo sensitivity adjustment (R 1053)
e)
Generator as under VII a) but with 5% pilot deviation
(± 3.75 kHz). Set R 1053 to the right hand end Stop, the
stereo lamp extinguishes. Slowly adjust R 1053 to the left
until the lamp just illuminates.
f)
Cross-talk damping (R 305, 307)
Stereo-coder SC 5, 10% pilot deviation, I kHz.
Depress button "R Connect AF-voltmeter via a low pass
— 15 kHz) to left channel loudspeaker output and
filter (fg
adjust with R 305/R 307 to minimum. Depress button
and measure right channel, if necessary adjust with R 305/
R 307.
g) RF stereo sensitivity adjustment
Generator with 6—7.5 kHz pilot deviation.
Level 20 PV on 240 Q, tune in receiver accurately, AFC
"on". Set R 1044 to fully right position — the stereo lamp
extinguishes, adjust control slowly to the left until the lamp
just illuminates. Reduce the RF level by approx. 20 dB, the
lamp must extinguish.
Image Osc. voltage
on point 4
TCA 440
3500 80 mv Align alternating L and C. finish off with
C-alignment.
L-side: Pointerto zero-marking.
2800 97 mV
Core positbns: Outer maximum
515 66 mV
—6dB
85 83 mV
19 75 mv
9 79 mV
Bemerkungen:
Remarks:
Für den CassettenbausteinCB210erscheintdie gesonderte
Service-Anleitung CB 200/ CB 210.
For the cassette unit CB 210 separate service manual
(CB 200/ CB 210) is available.
L