TB 9-6625-2182-35
Table 20. PM Accuracy
Measuring receiver phase
Test instrument
Test instrument
modulation indications (rad)
DATA carrier
DATA phase
frequency
modulation
Min
Max
8 MHz
75 rad
71.2
78.8
1050 MHz
100 rad
94.9
105.1
500 kHz
100 rad
94.9
105.1
(5) Perform steps (a) through (c) below for each row in table 21.
(a) Press ENTRY FREQ and enter DATA carrier frequency.
(b) Press SHIFT - ΦM and enter DATA rad.
(c) Using audio analyzer, measure the audio distortion. Distortion will indicate
within limits specified.
Test instrument
Test instrument
Audio analyzer
DATA
DATA
distortion indications
carrier frequency
phase modulation
(< %)
8 MHz
75 rad
0.4
1050 MHz
100 rad
0.4
500 kHz
100 rad
0.4
(6) Press RF OFF/ON pushbutton to OFF.
(7) Disconnect measuring receiver from TI OUTPUT RF.
b. Adjustments. No adjustments can be made.
18. Internal Oscillator
a. Performance Check
(1) Connect TI OUTPUT MOD to audio analyzer INPUT HIGH.
(2) Press TI pushbuttons as listed in (a) through (d) below:
(a)
INSTR PRESET.
(b)
SHIFT.
(c)
ENTRY - MOD OUT.
(d)
DATA - (+1 V).
(3) Press TI ENTRY MOD FREQ pushbutton and enter DATA modulated
frequency for each row in table 22. Set audio analyzer to measure distortion. Audio
analyzer will indicate within limits listed in table 22.
