TM 1-1520-238-10
3-15
Table 3-4.
RT-1167C/ARC-164(V) Controls and Functions – continued
Control
Function
VOL control
Adjust volume.
TONE button
Momentary switch. When pressed, causes 1,020 Hz tone to be transmitted on radio
operating frequency. Transmits TOD followed by a 1,020 Hz tone and used with A-3-2-T
switch for emergency clock start in AJ mode.
Mode selector
switch
Selects operating mode.
OFF
Turns power off.
MAIN
Enables main transceiver.
BOTH
Enables main transceiver and guard receiver.
ADF
Not used.
PRESET switch
Used to load the 20 preset channels in normal mode or WOD in AJ mode. Stores selected
data in specified preset channels.
NB-WB switch
Selects wideband or narrowband selectivity of main receiver.
MN-SQ (main
squelch) adjust
Sets the squelch level of the main transceiver
GD-SQ (guard
squelch) adjust
Sets the squelch level of the guard receiver.
3.7.3 Modes of Operation.
The radio set has the fol-
lowing modes of operation:
a. MAIN mode:
Two-way voice communication.
b. BOTH mode:
Allows using the main transceiver
with constant monitoring of the guard receiver.
c. GUARD mode:
Allows transmission and recep-
tion on guard frequency.
d. Normal Mode:
Single frequency used.
e. HQ mode:
The HQ mode of operation provides a
jam resistant capability by means of a frequency hopping
technique that changes frequency many times per sec-
ond. Automatic frequency changing in an apparently ran-
dom manner provides the jam resistance of the radio. The
HQ radios permit communication in radio-jamming envi-
ronments. Three elements are required for uninterrupted,
successful communication. Radios must use the word-of-
day (WOD), be time-synchronized with each other with a
time-of-day (TOD), and share a common net.
(1) WOD.
Common frequencies, hopping pat-
tern, and rate are determined by the operator entered
WOD. The WOD is a secret, tactical, multi-digit code that
changes daily, and is available worldwide to all HQ us-
ers.
The WOD programs the radio with the frequency hopping
pattern and rate. The hundredths/thousandths digits in the
channel 20 WOD element program the frequency hop rate
with .00 being the slowest and .75 being the fastest. WOD
elements vary in number and are entered by using one or
more of the six preset channels 20 through 15. Channels
containing WOD elements cannot be used in the normal
preset function. Transmissions can be made in WOD
channels, but they will not be on the frequency stored in
the preset channel memory.
