TB 9-6625-2182-24
(d) Using measuring receiver, measure FM deviation. Measuring receiver
deviation will indicate within limits specified in table 19.
Table 19. FM Deviation
Measuring receiver indications
Test instrument
(kHz deviations)
DATA
DATA carrier
DATA frequency
modulation
modulation (FM)
(MHz)
(kHz)
(kHz)
Min
Max
95
105
1050
100
100
26.3
256
100
25
23.7
196.4
256
100
187
177.6
393.8
256
100
375
356.2
157.5
50
10
150
142.5
b. Adjustments. No adjustments can be made.
17. Phase Modulation
a. Performance Check
(1) Set measuring receiver to measure FM with a 300 Hz high pass filter and
a 15 kHz low pass filter.
(2) Press TI pushbuttons as listed in (a) through (k) below:
INSTR PRESET.
(a)
ENTRY - AMPTD.
(b)
DATA - (+10 dBm).
(c)
SHIFT.
(d)
ENTRY - M.
(e)
MODULATION SOURCE - EXT DC.
(f)
ENTRY - MOD FREQ.
(g)
DATA - 1 kHz.
(h)
SHIFT.
(i)
ENTRY- MOD OUT.
(j)
DATA - (+1 V).
(k)
(3) Perform steps (a) through (c) below for each row in table 20.
(a) Press ENTRY FREQ and enter DATA carrier frequency.
(b) Press SHIFT - M and enter DATA rad.
(c) Set the measuring receiver to measure the PM. Phase modulation will
indicate within limits specified.