TM 1-1510-225-10
3A-117
1. Reply Indicator
2. Ident Code/Flight Level/Test Display
3. Photocell
4. Ident Switch
5. Ident Indicator
6. Function Switch
7. Code Selector Switch
8. Power Switch
9. Altitude Mode Indicator
10. ON Indicator
11. Standby Indicator
12. Digit Select Cursor
13. Flight Level Indicator
Figure 3A-69. Transponder Control Unit (MST 67A)
(b) SBY. Setting the function switch to
SBY puts the transponder in the standby mode.
(c) ON. Setting the function switch to
the ON position causes the transponder to provide
identification and position information.
(d) ALT. Setting the function switch to
the ALT position causes the transponder to provide
identification, position, and altitude information.
(e) VFR. Setting the function switch to
the VFR position will set the transponder code to 1200.
(7) Code Selector Switch. Momentarily
pressing the code selector switch will cause the cursor
to move to the right under the next digit of the
transponder code display. Rotating the code selector
switch clockwise or counterclockwise will change the
numerical value of the selected digit.
(8) Power Switch. Turning the power switch
clockwise from the OFF position applies electrical
power to the transponder.
(9) Altitude Mode Indicator. Illumination of
the altitude mode indicator, placarded ALT, indicates
that the transponder is providing aircraft identification,
position, and altitude information.
(10) ON Indicator. Illumination of the ON
indicator indicates that the transponder is providing
identification and position information but not altitude
information.
(11) Standby Indicator. Illumination of the
standby indicator, placarded SBY, indicates that the
transponder is in the standby mode.
(12) Digit Select Cursor. The digit select
cursor is used to select the digit that will be changed
by rotating the code selector switch.
