TB 9-6625-160-24
14. Audio Filters
a. Performance Check
(1) Press TI numerical key for 41.0 and then SPCL key to initialize TI.
(2) Set TI INPUT and OUTPUT FLOAT switches to ground, LOG/LIN switch to
LOG, and connect TI OUTPUT HIGH connector to INPUT HIGH connector.
(3) Set TI SOURCE AMPTD for 2 V.
(4) Set all TI filters to off (Led off).
(5) Set TI RATIO to off (Led off).
(6) Set TI to first SOURCE FREQ setting listed in table 18.
(7) Set TI RATIO to on (Led on).
(8) Set corresponding TI Filter in table 18 to on (Led on) and LOG-LIN button for a
dB indication on TI right display.
(9) TI right display must indicate -3.1 to -2.9 dB. If not, adjust TI SOURCE FREQ
ADJUST for required dB indication.
(10) TI FREQ displayed must be within values listed in Limits column of table 18.
(11) Repeat technique of (4) through (10) above for each remaining SOURCE FREQ
setting listed in table 18.
Table 18. Audio Filter.
Source
Filter
Limits (Hz)
Frequency (Hz)
High Pass/Low Pass
Minimum
Indicated
Maximum
400 Hz HP
400
360
440
30 kHz LP
30 k
28.000 k
32.000 k
80 kHz LP
80 k
76.000 k
84.000 k
(12) Press TI numerical key for 48.1 and then SPCL key.
(13) Set TI to first SOURCE FREQ setting listed in Source Freq column of
(14) Set all TI FILTERS to off (Leds off).
(15) Set TI RATIO to off (Led off).
(16) Set TI RATIO to on (Led on).
(17) Set TI for appropriate filter being verified by pressing appropriate TI filter button.
(18) TI right display must indicate within corresponding limits (dB) listed in
(19) Repeat step (18) for each remaining TI SOURCE FREQ listed in appropriate
(20) Set TI for any remaining Filter to be verified.
(21) Set TI to first SOURCE FREQ setting listed in SOURCE Freq column of
(22) Repeat technique of (18) and (19) for remaining TI SOURCE FREQ listed in
(23) Repeat technique of (20) through (22) for any remaining Filters installed in TI.
(24) When completed, set TI SOURCE AMPTD to 0 V.