TB 9-6625-2233-35
(e) ENTER.
(3) Set oscilloscope to display at least two waveform cycles at a convenient
amplitude and measure duty cycle.
(4) Oscilloscope duty cycle will display between 89.098 and 90.902 %.
(5) Repeat technique used in (2) (d) and (e) and (3) and (4) above, substituting
control settings and frequency counter indications listed in table 4.
b. Adjustments. No adjustments can be made.
Table 4. Symmetry
Oscilloscope duty cycle
Test instrument
display indications (%)
Pushbuttons
Symmetry
pressed
(displayed value)
Min
Max
2, 0, Enter
20 PCT
79.198
80.802
3, 0, Enter
30 PCT
69.298
70.702
4, 0, Enter
40 PCT
59.398
60.602
5, 0, Enter
50 PCT
49.498
50.502
6, 0, Enter
60 PCT
39.598
40.402
7, 0, Enter
70 PCT
29.698
30.302
8, 0, Enter
80 PCT
19.798
20.202
9, 0, Enter
90 PCT
9.898
10.102
10. FM Distortion
a. Performance Check
(1) Press pushbuttons as listed in (a) through (k) below:
(a)
CALIBRATE (allow enough time to complete and verify AUTOCALIBRATED
is displayed).
(b)
RESET.
(c)
(d)
1.
(e)
EXP.
(f)
7.
(g)
ENTER.
(h)
AMPLITUDE.
(i)
.15.
(j)
ENTER.
(k)
MODULATION FM/VCF.
(2) Connect equipment as shown in figure 1.
NOTE
Ensure audio analyzer and measuring receiver modulation
analyzer are in LOCAL mode.
