TB 9-4931-488-35
(21) Record multimeter dc indication as V dc.
(22) Set multimeter to measure ac volts and note V ac indication. Multiply this
indication by 1.414 and record as V pk.
(23) Compute the TI % of amplitude modulation (AM), using the following formula.
The computed result will be between min and max limits listed in table 25; if not perform b
below.
% AM = Absolute value of Vpk
x
100
(Vdc) - (Voff)
Where:
Voff = value recorded in (16) above
Vdc = value recorded in (21) above
Vpk = value recorded in (22) above
NOTE
If an out-of-tolerance condition is noted in (24) through (27)
below, disconnect input to measuring receiver and insure Voff
value recorded in (16) above has not changed before performing
b below
(24) Repeat technique of (20) through (23) above for multimeter indications listed in
(25) Adjust AM control fully ccw. Set switch A26A8S1 (fig. 2) to DC position. Repeat
technique of (20) through (24) above for multimeter indications listed in table 26.
Computed results will be as specified; if not, perform b below.
(26) Adjust AM control fully ccw. Set RANGE MHz switch to 512-256 and adjust
(27) Repeat technique of (15) through (25) above.
(28) Reduce all outputs to minimum.
True RMS voltmeter
Computed results
(%)
Indications
Min
Max
(V Ac)
1.000
19.6
20.4
1.500
29.4
30.6
2.000
39.2
40.8
2.500
49.0
51.0
3.000
58.8
61.2
3.500
68.6
71.4
4.000
78.4
81.6
34
