RDL/DDM/MOD DISPLAY

TM 11-6625-2975-12

2-2. CONTROLS AND INDICATORS. (CONT)

RDL/DDM/MOD DISPLAY

RDL/DDM/MOD display provides readout of selected radials (RDL) from 000.00 to 359.99 degrees

(DEG), readout of difference in depth of modulation (DDM) in 0.001 increments, and readout of

percent modulation (MOD). In addition to the five-digit, seven-segment display, there area number

of indicators associated with the display. Their function is to indicate the type of information being

displayed. Table 2-5 shows individual indicator functions.

TABLE 2-5. RDL/DDM/MOD LED INDICATOR FUNCTIONS

FUNCTION

INDICATOR

indicates that a TO radial has been selected.

Indicates that a FROM radial has been selected.

FROM

Indicates that the next DDM step will be in the up or left

U/L (150 Hz)

direction. (LOC or GS modes only.)

Indicates that the next DDM step will be in the down or right

D/R (90

Hz)

direction. (LOC or GS modes only.)

Indicates that a VOR radial has been selected.

RDL (DEG)

Indicates ILS difference in depth modulation selection and

DDM

adjustment.

Indicates selection of percent modulation function.

MOD (%)

Associated with RDl/DDM/MOD display is AUDIO STATUS display. AUDIO STATUS consists of two

indicators. Table 2-6 shows individual indicator functions.

2-6