Section III. VEHICULAR RADIOS

11-5820-89020-3

SECTION III

VEHICULAR RADIOS

3.1.

OPERATIONAL CHECK.

IMPORTANT POINTS TO REMEMBER IN USING THE OPERATIONAL CHECK

When an Operational Check step involves an item of equipment which is not used in the

system being checked, merely skip that step and continue to the next step.

It is important that Operational Check steps be performed as stated and in the order

presented.

If a VIC is used with the UUT, determine as early as possible whether the problem is in the VIC

or the radio; then troubleshoot that part of the system. (Refer to Chapter 2, TM 202, for details)

. When the Operational Check is complete, make a communications check (unless prohibited)

and repeat the Operational Check to ensure the system is completely operational,

. When removing or installing components, ensure VAA CB1 is in the OFF position.

Do not accept power outputs less than those specified.

Before beginning an Operational Check on any vehicular radio system, verify good power with

engine running and engine off, Obtain assistance of unit vehicle mechanic as required.

Step 1. PREPARATION

STEPS

CHECKS

ACTIONS

1.1 Set RT:

FCTN . to OFF

N/A

CHAN to 1

MODE to SC

N/A

RF PWR to HI

N/A

VOL to Mid-Range

N/A

DIM to Full CW

N/A

COMSEC to Z

N/A

1.2 Set VAA

N/A

CB1 to OFF

N/A

DS1 to Full CCW

N/A

If LS-671 or VIC is used:

Ensure VAA is set to REMOTE.

Set VAA to REMOTE

If neither is used:

Ensure VAA is set to LOCAL.

Set VAA to LOCAL

1.3 Set all LS-671:

CB1 to OFF

N/A

DS1 to Full CCW

N/A

VOL to OUT/Mid-Range

N/A

1.4 Set PA Mount:

CB1 to OFF

N/A

DS1 to Full CCW

N/A

1.5 Handset (HS), H-250:

Ensure HS is operational and dis-

Install known good HS

connect all other handsets.

Connect to VAA

N/A

J3 (RT-A)/J2 (RT-B)