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and the Meter Range to +10 dB (1 mW).
(18)
Select the FM mode, adjust the AM/FM signal generator frequency for 1.5
MHz with an output of -40 dBm and modulate the signal at 1 kHz
with a peak deviation of +4 kHz. Check the audio output indication on the
distortion analyzer meter. Adjust coil L3 for peak audio output.
(19)
Turn Receiver off. Disconnect all test equipment and replace filter assembly
cover.
f.
ISB IF/AF, Circuit Card Assembly A5.
This circuit card is an optional assembly and may not be present in all Receivers. If
it is used, the A5 assembly is ins talled in the top portion of the Receiver, towards
the rear. The test equipment required to align the A5 module includes the spectrum
analyzer, AM/FM signal generator, digital multimeter, and RF
shown in Table 1-2.
NOTE
The
LK
1 link on the A4 circuit card must be ins talled for ISB operation and the
alignment procedures for A4 must be performed prior to any adjustment on the A5
circuit card.
(1)
Connect
the
panel. Turn the Receiver on and adjust frequency to 1.5000 MHz, AGC to
MAN, IF gain to maximum and mode to LSB.
(2)
Connect
the
meter to TP7 on circuit card A5. Set the AM/FM signal generator to 1.4982
MHz at an output level of 30 uVolts (-73 dBm).
Racal RA6790/GM Alignment & Tuning Manual
AM/FM
signal
high
impedance
generator
to
Jl-RF
test
probe
of
Millivoltmeter,
IN
on
the
rear
the
RF
millivolt-
Page 9 of 20
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