TB 9-6625-2077-35
Test instrument
Measuring receiver
MODULATION
indications
meter indications
(kHz)
(kHz)
Min
Max
25
21.25
28.75
50
42.5
57.5
75
63.75
86.25
(14) Set MODULATION switch to FM 150 Hz and FM METER RANGE switch to
75 KHz.
(15) Set RF OUTPUT switch to 0 dBm and adjust RF OUTPUT LEVEL control for
a 0 dBm indication on TI RF OUTPUT meter.
(16) Adjust MODULATION
LEVEL
control
for
a
75
kHz
indication
on
MODULATION meter.
(17) Set audio analyzer to measure distortion.
Table 10. Distortion
Test instrument
Audio analyzer
MODULATION
distortion
switch setting
indication
(Hz)
(%)
150
<4
400
<4
1000
<4
(18) Measure FM distortion at 150 Hz. If audio analyzer distortion indication is not
less than 4.0 percent, perform b below.
(19) Repeat (15) through (17) above with MODULATION switch set at FM 400 Hz
and FM 1 KHz listed in table 10.
b. Adjustments
(1) Set POWER switch to OFF.
Remove assembly A5 and reconnect, using
extender board (fig. 1).
(2) Position controls as listed in (a) through (h) below:
(a) POWER switch to ON.
(b) MODULATION switch to CW.
(c) MODULATION LEVEL control fully ccw.
(d) FM METER RANGE switch to 10 KHz.
(e) TUNING RANGE switch to 16-90 MHz (16-80 MHz).
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