the audible indicators used for determining the
operational condition of the radio. Section II contains
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.
CONTROLS AND INDICATORS
LOW BATTERY INDICATOR.
clicking sound indicates that the battery voltage has
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
The controls, indicators,
be replaced or recharged.
and connectors of the receiver/exciter (fig 2-1) are listed
in table 2-1.
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
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