TB 9-6625-2343-50
(d) HP FILTER 50 Hz.
(e) DETECTOR AVG.
(f) LP FILTER 3 kHz.
(12) If TI indication is not ≤ 0.01%, perform b below.
(13) Connect equipment as shown in figure 1.
AUDIO ANALYZER
AUDIO
CALIBRATOR
AM/FM
TEST INSTRUMENT
TEST SOURCE
CABLE AND TERMINATION SUPPLIED
WITH WIDEBAND OPTION
AUDIO
INPUT
AM FM/32
SIGNAL GENERATOR NO. 3 OUTPUT
Figure 1. AM distortion.
(14) Set calibrator for a wideband output of 20 kHz at an amplitude of 215 mV.
(15) Turn all TI HP FILTERS and LP FILTERS off.
(16) Press TI keys as listed in (a) and (b) below:
(a) DETECTOR PEAK+.
(b) MEASUREMENT AM.
(17) Adjust calibrator wideband output for a TI indication of 50 percent AM.
(18) Set the audio analyzer to measure distortion with 80 kHz low-pass filtering.
(19) The audio analyzer will indicate within the limits specified in the first row of
(20) Repeat technique of (14), (17) and (19) above for remaining frequency and AM
percent settings in table 3. The audio analyzer will indicate within the limits specified in
Table 3. AM Distortion
Calibrator
Test instrument
Audio analyzer
AM indication (%)
Indicated limit (%)
20 kHz
50
≤ 0.3
20 kHz
95
≤ 0.6
50 Hz
95
≤ 0.6
50 Hz
50
≤ 0.3
(21) Set calibrator for a wideband output of 1 kHz at an amplitude of 383 mV.
(22) Adjust calibrator output amplitude for a TI indication of 80 percent AM.
(23) Press calibrator NEW REF key.
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