IFR NAVAIR NAV-750

NAVAIR 17—2OAX—737
4.4.3.15 Verify that the DMM indicates between —40.0 and + 40.0 mV dc.
4.4.3.16 Adjust the TI 9960 FM tone modulation controltoUNCAL [fully ccw (0)].
4.4.3.17 Verify that the oscilloscope displays a 30 Hz tone, and that the DMM indicates between —40.0
and +40.0 mV dc.
4.4.3.18 Set the TI 9960 Hz tone modulation control to the CAL (UNCAL lamp off) position, and set the
FREQUENCY MHz switches to 118.000.
4.4.3.19 Verify that the oscilloscope displays a 1020 Hz tone, and that the DMM indicates —40.0 to
+40.0 mV dc.
4.4.3.20 If the TI is a NAV—750B continue with step 4.4.3.21. Otherwise, if the TI is not a NAV—750B,
proceed to step 4.4.3.27.
4.4.3.2 1 Set the TI meter function and toneselector switch to 400 Hz.
4.4.3.22 Verify that the oscilloscope displays a 400 Hz tone, and that the DMM indicates between —80.0 to
+ 80.0 mV dc.
4.4.3.23 Set the TI meter function and tone selector switch to 1300 Hz.
4.4.3.24 Verify that the oscilloscope displays a 1300 Hz tone, and that the DMM indicates between —80.0
and + 80.0 mV dc.
4.4.3.25 Set the TI meter function and tone selector switch to 3000 Hz.
4.4.3.26 Verify that the oscilloscope displays a 3000 Hz tone, and that the DMM indicates between —80.0
to +80.0 mV dc.
4.4.3.27 Disconnect the oscilloscope and the digital multimeter from the TI.
4.5 TONE FREQUENCY TESTS
4.5.1 Setthe TI controls as follows:
FREQUENCY MHz switches to 108.000
LOC—G/S frequency switch to LOC
BEARING-FREQ switch to FREQ
MASTER MOD control to CAL (UNCAL lamp off)
1020 Hz indent tone MOD control to CAL (UNCAL lamp off)
9960 Hz FM tone MOD control to CAL (UNCAL lamp off)
30 Hz tone MOD control to CAL (UNCAL lamp off)
LOC DDM switch to 0
G/S DDM switch to 0
4.5.2 Connect the electronic counter, set for a 30 Hz measurementandAC coupled, input to the TI rear
panel 30 Hz REF jack.
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