TB 9-4931-488-24
(8) Set RANGE MHz switch to 512 - 256 and adjust FREQUENCY TUNE for TI
display indication of 512 MHz.
(9) Set measuring receiver for FM deviation measurement with peak + detector.
(10) Set PEAK DEVIATION switch to settings listed in table 30 and adjust pulse
generator controls for TI meter indications listed in table 30. If measuring receiver does
not indicate as specified perform b below.
Table 30. FM Accuracy.
Test instrument
Measuring receiver indications
PEAK DEVIATION
Meter indications 1
Min (kHz)
Max (kHz)
switch settings
5
5
4.58
5.43
10
10
9.15
10.8
20
20
18.1
21.9
40
40
36.5
43.5
80
80
72.9
87.1
160
160
144
176
320
320
293
347
1 Use
scale reference that is lit up under SCALE to left of TI meter.
(11) Set RANGE MHz switch to 64 - 32 and adjust FREQUENCY TUNE for
FREQUENCY MHz display indication of 32 MHz.
(12) Set PEAK DEVIATION switch to 320 kHz and adjust FM control fully cw.
(13) Set measuring receiver to measure FM deviation then adjust pulse generator
output for 320 kHz measuring receiver indication. If distortion is not ≤ 3%, perform b
below.
(14) Repeat technique of (11) through (13) above, using settings listed in table 31. If
the FM distortion does not indicate as specified perform b below.
Table 31. FM Distortion.
Test instrument
Measuring receiver
FREQUENCY TUNE
Max FM distortion
PEAK DEVIATION
and FINE TUNE
Peak deviation indication
switch settings
indication
control settings
(kHz)
(<%)
(kHz)
(MHz)
32
320
320
3
32
40
40
1
45
40
40
1
45
320
320
3
64
320
320
3
64
40
40
1
(15) Set RF OFF/ON switch to OFF.
37
