TB 9-6625-2076-24
(6) Press TONE SELECT 1020 Hz pushbutton (all other TONE SELECT
pushbuttons off). If multimeter does not indicate between 1.4985 and 1.5015 V rms,
perform b (4) below.
(7) Connect multimeter to TI DEMOD output (rear panel). Repeat (3) through (5)
above. Calculated ratio will be between 0.99720 and 1.00280.
(8) Connect equipment as shown in figure 3.
(9) Set each decade resistor to 47 k .
(10) Press TONE SELECT 90 Hz pushbutton (all other TONE SELECT
pushbuttons off) and enter a DDM setting of 0.046 into TI. Record multimeter indication.
(11) Press TONE SELECT 150 Hz pushbuttons (all other pushbuttons off). Record
multimeter indication.
Figure 3. Localizer DDM - equipment setup.
NOTE
Proper DDM steps can be entered by pressing
FUNCTION/CONTROL STEP RDL DDM pushbutton.
(12) Divide value recorded in (11) above by value recorded in (10) above. Calculated
ratio will be between 1.25861 and 1.26116.
(13) Repeat technique of (10) through (12) above for each DDM setting listed in table
9. Calculated ratio will be within limits specified.
Table 9. Localizer DDM
Test instrument
Calculated ratio limits
DMM settings
Min
Max
0.093
1.60417
1.60756
0.155
2.26264
2.26797
0.200
2.99600
3.00400
11