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FM RADIO ALIGNMENT PROCEDURE
CONNECTION OF THE MEASURING INSTRUMENTS
Test Oscillator
400Hz 22.5KHz dev.
'Link Coil (Diameter 3 - S5cm)
PRELIMINARIES
1
2
Set the VTVM to about 3V, AC range.
Make a link coil of diameter 3 - 5cm(2'') as illustrated
for the test oscillator output and set it on RLO2 when
FM
IF
adjustments
are
performed.
Connect
the
oscillator output to the FM antenna terminals for some
other adjustments.
FM IF ADJUSTMENT (10.7MHz Adjustment)
1
2
Set the link coil on RLO2.
Set the test oscillator to 10.7MHz and adjust IFT RTO2
for maximum on the VTVM.
Minimize the test oscillator output as much as possible
and adjust IFT RTO1
and RTO2 for maximum
on the
VTVM. (Repeat the adjustment two or three times.)
FM FREQUENCY
RANGE ADJUSTMENT
(Adjustment to cover 87.2MHz - 109MHz)
1 Set the test oscillator to 87.2MHz and connect it to the
FM antenna terminals.
Turn the Radio Tuning Knob to the lower frequency.
(Tuning Capacitor plates fully meshed).
Adjust
RLO3
for maximum
indication
on the oscillo-
scope and
VT VM.
*
After adjustment, secure RLO3 with paraffin.
Set the test oscillator to 109.0MHz and turn the Radio
Tuning Knob to the higher frequency.
(Tuning Capacitor plates fully open).
Adjust the trimmer capacitor (VCT-FC1)
on the tuning
capacitor for maximum
indication on the oscilloscope
and VTVM.
VTVM
or Tester
Oscilloscope
To Point SX of the TV PCB.
FM TRACKING ADJUSTMENT
1
Set
the
test
oscillator
to
90.0MHz
and
connect
the
_ Output to the FM antenna terminals.
Set the Radio
Dial to 90.0MHz
and adjust RLO1
for
maximum.
*
After adjustment, secure RLO1 with paraffin.
Set the test oscillator and the Radio Dial to 105.0MHz.
Adjust the trimmer capacitor (VCT-FC2)
of the tuning
capacitor for maximum
amplitude on oscilloscope and
VTVM
indication.
Repeat
the
FM
Frequency
range
and
FM
tracking
adjustments two or three times.
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