Chapter 2. OPERATING INSTRUCTIONS - TM-11-5820-919-120038

TM 11-5820-919-12

CHAPTER 2

OPERATING INSTRUCTIONS

2-1. INTRODUCTION.

the audible indicators used for determining the

operational condition of the radio. Section II contains

information for selecting the proper antenna, frequency,

2-2. This chapter contains the necessary information

mode, and site to achieve best communication at any

for operation of the radio set.

It also discusses

time and place. Additional information in support of this

operating considerations essential for achieving optimum

section is contained in Appendix II which discusses the

results in various operating environments. Section I

propagation of radio waves and develops some

contains the controls and indicators for the

situational examples for optimizing communication with

receiver/exciter and amplifier/coupler units, including

the radio set.

SECTION I

CONTROLS AND INDICATORS

2-10.

LOW BATTERY INDICATOR.

A repetitive

clicking sound indicates that the battery voltage has

2-3. GENERAL.

fallen to less than 20 volts and that the battery is nearly

exhausted. The clicking sound will first be heard during

2-4. This section describes the controls and indicators

a tune-up or voice transmission, and will stop when the

contained on the receiver/exciter and amplifier/coupler

PTT switch is released and the radio reverts to the

units. It also discusses the audible indicators, as heard

receive conditions, where the battery drain is a minimum.

in the handset, which tell about the operational condition

At this point, the battery retains enough charge to permit

of the radio set.

about 1 hour of receive operation, with five or six very

brief voice transmissions during the hour. When the

2-5. CONTROLS AND INDICATORS.

battery voltage falls low enough that the clicking sound is

heard continuously in the receive mode, the battery must

2-6. RECEIVER/EXCITER.

The controls, indicators,

be replaced or recharged.

and connectors of the receiver/exciter (fig 2-1) are listed

in table 2-1.

2-11.

POWER OUTPUT INDICATOR. If, while

transmitting, the operator hears his voice in the handset

2-7 AMPLIFIER/COUPLER. The controls, indicators

earpiece, he is hearing what is called sidetone. The

and connectors of the amplifier/coupler (fig 2-1) are

presence of sidetone guarantees that the radio set is

listed in table 2-2.

actually generating an rf signal and that the power output

is within 3 db (50%) of the normal limits. The absence of

2-8. AUDIBLE INDICATORS.

sidetone means the handset or radio set is defective.

2-9. Five distinctive audio signals in the handset are

2-12.

TUNING INDICATOR. If the ANT SEL switch is

provided to tell the trained operator much about the

in the BNC or whip position and the radio has just been

operational condition of the radio set. Additionally, the

turned on, the tuning operation will begin the first time

audio signals can be used to effect a bypass mode of

the PTT switch is pressed. A continuous 1-kHz tone will

operation when the antenna VSWR is less than 1.5:1.

be heard in the handset during the tuning operation.

The PTT switch may be released until the tuning

operation is complete. When the tone ceases, an

increase in receiver noise level (static) indicates that the

antenna has been matched and that the radio is now

receiving atmospheric noise. If the tone ceases but the

receiver noise level does not

2-1