Grundig Sonoclock 51 SC 5301, Service Document

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Sonoclock 51 SC 5301
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EQUIPMENT REQUIRED
Signal Source
1.MW/LW signal generator (AM SG)
2. FM signal generator (FM SG)
3. Sweep generator (10.7 Mhz for FM)
Output Indicator
1. SSVM
2. Oscilloscope
3. Frequency Counter
General preparation
1. Check source voltage.
2. Set function switch to band being aligned
3. Turn volume control to minimum (unless noted otherwise)
4. Connect low side of signal and output indicator to chassis ground unless otherwise specified.
Keep ground connection close to high side connection.
5. Keep signal inout as low as possible to avoid AGC and AFC action
(set output indicator to high sensitivity.)
6. Standard modulation is 1000 Hz AT 30% amplitude for MW/LW (1000 Hz at 22.5 kHz deviation for FM)
AM IF ALIGNMENT
Step
Signal source (AM RF Gen) Connect
to
Set signal to
Aligment indicator connect to
Oscilloscope or SSVM
Set radio dial to Adjust Adjust for Remarks
1 A standard radiation loop 460 KHz T4 Detector Output Terminal Quiet point T3 Maximum
Volume control min
position
2 Repeat for maximum output
MW RF ALIGNMENT
Signal source (AM Signal Gen.)
connect to
Set signal to Alignment indicator Connect to Set radio dial to Adjust Adjust for Remarks
1
515 KHz
(modulated)
515 KHz
(lowest end)
T1 (Osc,
coil)
2
1640 KHz
(modulated)
1640 KHz
(Highest end)
TC4
(Osc, trim)
3
600 KHz
(modulated)
600 KHz L2 (ant coil)
4
1440 KHz
(modulated)
1440KHz TC3 (ant trim)
5 Repeat Steps 3 and 4 as necessary to minimize tracking error. Also repeat steps 1 and 2 if necessary.
LW RF ALIGNMENT
Signal source (AM Signal Gen.)
connect to
Set signal to Alignment indicator Connect to Set radio dial to Adjust Adjust for Remarks
1
140 KHz
(modulated)
140 KHz
(lowest end)
T2 (Osc,
coil)
2
290 KHz
(modulated)
290 KHz
(Highest end)
TC6 (Osc,
trim)
3
153 KHz
(modulated)
153 KHz L3(ant coil)
4
261 KHz
(modulated)
261 KHz TC5 (ant trim)
5 Repeat Steps 3 and 4 as necessary to minimize tracking error. Also repeat steps 1 and 2 if necessary.
FM RF ALIGNMENT
Step
Signal source (FM Signal Gen.)
Connect to
Set signal to
Alignment indicator (oscilloscope ,
VTVM Connect to
Set radio dial to Adjust Adjust for Remarks
1
87.35 MHz
modulated
87.35MHz
(lowest end)
L1 (Osc, coil)
2
108.25 MHz
modulated
108.25MHz
(Highest end)
TC2
(Osc, trimmer)
3
90 MHz
modulated
90MHz
L2 (RF coil)
stretch or
squeeze
4
106 MHz
modulated
106MHz TC1 (RF trim)
5 repeat steps 3 and 4 as necessary to minimum tracking error. Also repeat steps 1 and 2 if necessary.
* UK models must not be able to tune below 87.5 MHz.
Across speaker voice coil Maximum
Volume control max-
position
TP 1, GND (Test point) through
matching network if necessary
Across speaker voice coil Maximum
Volume control Max-
position
A standard radiation loop antenna
ALIGNMENT PROCEDURE
MODEL NO. GRUNDIG SONOCLOCK SC 51
A standard radiation loop antenna Across speaker voice coil Maximum
Volume control max-
position