TB 6-6625-2329-24
(16) Press PARAMETERLEVEL pushbutton and press ON/OFF OFF key.
(17) Reduce output on audio analyzer.
b. Adjustments. No adjustments can be made.
15. Frequency Modulation
a. Performance Check
(1) Press SHIFT INSTR PRESET pushbutton.
(2) Set measuring receiver to measure FM deviation, with 50Hz high and 15kHz low
pass filters on and PEAK + detector.
(3) Press pushbuttons as listed in (a) through (c) below:
(a) PARAMETER RF, enter DATA 100 numerical value, and press
ENTER/UNITS MHz key.
(b) PARAMETER LEVEL, enter DATA 0 numerical value, and press
ENTER/UNITS dBm key.
(c) PARAMETER AF, enter DATA 1 numerical value, and press
ENTER/UNITS kHz key.
(4) Press TI PARAMETER FM pushbutton, enter DATA numerical value, and
press ENTER/UNITS kHz key for each row table 24. Using measuring receiver and FM
measurement techniques, modulation will be between specified limits.
Table 24. FM Accuracy
Measuring receiver modulation indications
Test instrument
DATA and
FM
ENTER/UNITS
(kHz)
(kHz)
Min
Max
1
0.93
1.07
3
2.83
3.17
10
9.48
10.52
30
28.48
31.52
100
94.98
105.02
(5) Press PARAMETER FM pushbutton and press ON/OFF OFF key.
(6) Setup measuring receiver to measure modulation distortion.
(7) Adjust controls as listed in (a) through (c) below for each row in table 25 below:
(a) Press TI PARAMETER RF pushbutton, enter DATA numerical value and
press ENTER/UNITS MHz key.
(b) Press TI PARAMETER FM pushbutton, enter DATA numerical value,
and press ENTER/UNIT kHz key.
(c) Using measuring receiver and distortion measurement techniques,
distortion will be between specified limits.
