Technics QUARTZ ST-K50

m@ MEASUREMENTS AND ADJUSTMENTS
FM ADJUSTMENT
Control positions and equipment used
@ FM signal generator(FM-SG)
@ Frequency counter
@ Choke coil(100yH)
@ Resistor(100kQ)
@ Stereo modulator
@ Distortion analyser
e@ DC electronic voltmeter(EVM)
Note: For Z201 (AM ANT and OSC coil), 2202 (AM-IFT), they are supplied as adjusted parts. So, do not turn the cores of the parts.
It is not necessary to adjust the AM circuit.
FM MONO DISTORTION ADJUSTMENT
FM SIGNAL GENERATOR CONDITION
1.Test equipment connection is shown in figure. Modulation
2.Set the unit to “FM” mode.
3.Set the radio frequency display and signal generator to Output level
100.10MHz.
4.Adjust the core of T201 so that the voltage measured in
signal mode is OmV(0420mV) in 300mV range.
5.Adjust T202 so that the distortion factor of L-CH is minimized.
6.Repeat steps 4 and 5.
7.Make sure that the distortion factors of L-CH and R-CH
are nearly the same and minimum.
Note: The adjusting screwdriver used should be made of
resin.
MPX VCO ADJUSTMENT
1.Test equipment connection is shown in figure.
2.Set the unit to ‘‘auto”’ position.
3.Set the radio frequency display and signal genarator to
100.10MHz.
4.Adjust VR301 for 19kHz+30Hz on frequency counter
reading.
USING ALTERNATE SYSTEM
1.Receive the stereo broadcast.
2.Adjust VR301 until stereo indicator lights up. Fix the arm
of VR301 as shown in figure.
FM SIGNAL GENERATOR CONDITION
Modulation 0% (non-modulation)
Output level
Modulation frequency
Frequency counter
“Stereo” OFF position
“Stereo” ON position
(Indicator lighting)
Adjust point of pilot
circuit
e ADJUSTMENT POINTS
AM LOOP ANT an on
TPUT 1
SULEUL AM ANT [ If
REMOTE
CONTROL
—_—4
FM MPX VCO
(19kHz)
FM offset FM MONO
720i DISTORTION
ea)
™ DESCRIPTION OF FL PANEL [FL901 (SAD8MT10ZYk)]
¢ GRID ASSIGNMENT
7G 6G 3G 2G
h
quartz lock
Note: The grid of 3G and 8G are used for external connection.
e PIN CONNECTION
CONNECTION F1 AM |MW| CA |LW] 7G je | oof»
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| PINNO. | 18)