Chapter 2. OPERATING INSTRUCTIONS - TM-11-5895-217-120025

CHAPTER 2

OPERATING INSTRUCTIONS

17. Control and Indicators

T h e control unit provides for remote

(fig. 6)

c o n t r o l of the transponder set. The fol-

Note: This paragraph covers only items used b y

l o w i n g chart lists the controls and in-

the operator; items used by maintenance personnel

dicators on the control unit and their func-

are covered in instructions for the appropriate main- .

tions:

tenance echelon.

Function

Control or indicator

Turns transponder set off or on, selects receiver sensitivity, and provides for

Master control - - - - - - - - - - - -

emergency operation.

Sw pos

Action

OFF - - - - - - - - - -

Turns transponder set off.

Places transponder set in warmup (standby) condition.

STAY---------

LOW - - - - - - - -

Applies complete power to transponder set but with reduced

receiver sensitivity in accordance with military character-

istics to meet certain operational requirements for tactical

conditions.

NORM - - - - - - - - -

Applies complete power to transponder set with maximum

receiver sensitivity.

EMER - - - - - - - - -

Permits automatic transmission of emergency signals.

Selects operational mode.

Function control - - - - - - - - - - - -

Sw pos

Action

Permits transponder set to reply with normal pulse codes,

NORMAL - - - - - - - - -

representing modes 1, 2, and 3.

MOD - - - - - - - -

Permits transponder set to reply with sif pulse codes, rep-

resenting modes 1, 2, and 3.

---------

Permits transponder set to reply with civil pulse codes, rep-

CIVIL

resenting modes 1, 2, and 3.

I/P switch - - - - - - - - - - - - - - -

Enables i/p reply operation.

Action

Sw pos

MIC - - - - - - - - - - -

Connects i/p energizing circuits to aircraft microphone key

circuits and permits aural i/p for 30 seconds when speak-

ing into microphone.

OFF-----------

Disconnects microphone keying and i/p initiating circuits.

I/P - - - - - - - - - - -

When momentarily actuated (spring-loaded), initiates i/p

operation for 30 seconds.

Permits monitoring transmitted reply pulses, when set to ON position.

AUDIOswitch-------------

MODE 2 switch - - - - - - - - - - - -

Permits transponder set to provide mode 2 replies for mode 2 interrogations.

MODE 3 switch - - - - - - - - - - -

Permits transponder set to provide mode 3 replies for mode 3 interrogations.

MODE 1 code control - - - - - -

Selects and indicates the two-digit, mode 1 code number.

First digit selector selects first digit of mode 1 code number.

Second digit selector selects second digit of mode 1 code number.

-----

Selects and indicates the two-digit, mode 3 code number.

MODE 3 code control

First digit selector selects first digit of mode 3 code number.

Second digit selector selects second digit of mode 3 code number.

Prevents accidental placement of the master control to the EMER position.

Emergency barrier- - - - - - -

Lights when power is applied to transponder.

Pilot light- - - - - - - - - - - - -

---------

Controls brilliance of pilot light.

Lens shutter

Permits test of pilot light.

Test button- - - - - - - - - - - -

18. Power Switches and Controls

lated to the operation of the equipment.

These controls are supplied as part of the

The following controls are not a part of

aircraft in which the set is installed.

the transponder set but are directly re-

Function

Control

When actuated, makes power available to the aircraft circuit breakers.

Master power on-off switch

When actuated, primary power is made available to the transponder set.

AN/APX-44 circuit breaker