Table of Contents
Advertisement
3.6 MULTIPLEX ALIGNMENT
1
2
. 3.
4,
Connect a frequency Counter to test point J301.
Set the FM signal generator to provide 60 dB {1 mV) at
98 MHz.
Tune the receiver to the same frequency so that the cen-
ter tuning meter pointer indicates its center.
Turn off the modulation
of the FM signal generator and
adjust the R304 (@) so that the frequency counter may
a precisely react 19.08 kHz.
"3.7
STEREO SEPARATIGN
ALIGNMENT
1, Set the FM signal generator to provide stereo composite
signal and tune the receiver to the same frequency so
that the center tuning meter pointer indicates its center.
. Adjust the R313
()} for maximum
and same separa-
tion in both channels.
3.8 MUTING
LEVEL ALIGNMENT
1.
2.
3.
Set the FM signal generator to provide 22 dB {12,6 nV)
at 98 MHz,
,
Set the modulation of FM
signal generator to 1 kHz,
100%,
,
Tune the receiver to the same frequency so that the cen-
ter tuning meter pointer indicates its center.
. Turn on FM MUTING
pushswitch.
. Turn the R207 (C1) until the output waveform disap-
pears and adjust it to a point where the waveform comes
to appear again:
Figure 2. Dial Stringing
4. AM ALIGNMENT PROCEDURES
(Selector switch in the AM position)
4.1
AM IF ALIGNMENT
1
Connect a sweep generator to the tuning capacitor C120
{for AM
oscillator) and an alignment
scope to the test
point JAGG.
. Rotate
each
core
of IF transformers
LAGS
(()) and
LAO6 (D) for maximum height and flat top symmetrical -
response.
4.2 AM TRACKING
ALIGNMENT
1. Set the AM signal generator to 520 kHz. Tum 'the tuning
capacitor fully closed
(place the tuning pointer at the
low end) and adjust the oscillator coil LAO4
(OD) for
_ maximum audio output.
. Set the AM signa! generator to 1650 kHz, Piace the tun-
ing pointer
in the high frequency end and adjust the
trimming capacitor TC,
((L)) for maximum audio output.
. Repeat steps 1 and 2 until no further adjustment is nec-
essary.
. Set the AM signal generator to 600 kHz and tune the re-
ceiver to the same
frequency and adjust a slug core of
AM ferrite-rod antenna LO51 (K)} for maximum output,
. Set the generator to 1400 kHz and tune the receiver to
the
same
frequency
and
adjust
the
antenna
trimming
capacitor TC, (KK) for maximum output,
. Repeat steps 4 and 5 until no further adjustment is nec-
essary.
NOTE:
Use the loop for AM tracking alignment.
Advertisement
Table of Contents
