TB 9-6625-2343-40
Table 9. Φ Modulation, 250 kHz FM Deviation.
Test instrument
Calibrator
FM deviation
Φ Modulation indication
initial output
indication
(rad)
Frequency
Level (mV)
(kHz)
Min
Max
1 kHz
446.3
250
242.4
257.6
20 kHz
454.9
250
12.0
13.0
(16) Move TI sensor module from AM/FM test source FM OUTPUT to FM/32 OUTPUT.
(17) Set calibrator for a wideband output frequency of 20 kHz at a level of 233.3 mV.
(18) Press TI keys as listed in (a) and (b) below:
(a) AUTOMATIC OPERATION.
(b) MEASUREMENT FM.
(19) Adjust calibrator level for a TI indication of 4 kHz.
(20) Press TI keys as listed in (a) through (c) below:
(a) MEASUREMENT ΦM.
(b) AUTOMATIC OPERATION.
(c) MEASUREMENT ΦM.
(21) If TI indication is not between 0.193 rad and 0.207 rad, perform b below.
(22) Move TI sensor module from AM/FM test source FM/32 OUTPUT to FM/4 OUTPUT.
(23) Press TI keys as listed in (a) through (c) below:
(a) DATA 3.1.
(b) DATA SPCL.
(c) MEASUREMENT FM.
(24) Set calibrator for a wideband output frequency of 10 kHz at a level of 179.4 mV.
(25) Adjust calibrator level for a TI indication of 25 kHz.
(26) Press TI MEASUREMENT ΦM key.
(27) If TI indication is not within limits specified in the first row of table 10, perform
b below.
(28) Repeat technique of (23)(c) and (24) through (26) above for remaining calibrator
initial settings and TI FM deviations in table 10. If TI indications are not within limits
specified in table 10, perform b below.
Table 10. Φ Modulation Accuracy
Test instrument
Calibrator
FM deviation
Φ Modulation indications
initial output
indication
(rad)
Frequency
Level (mV)
(kHz)
Max
Max
10 kHz
179.4
25
2.39
2.61
10 kHz
18
2.5
0.239
0.261
1 kHz
178.5
25
24.0
26.0
200 Hz
84
5
24.0
26.0
24