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TM 55-1520-228-10

Change 11 3-8.3

(4)

1020 Hz TONE Signal Transmission (MAIN)

mode.

(a)

Set OFF-MAIN-BOTH-ADF selector

switch to MAIN.

(b)

Select a desired frequency for TONE

transmission. Refer to steps 3-26.a.(2)(c) and (d).

(c)

Push the TONE switch to transmit the

1020 Hz signal.

NOTE

Tone-modulated signal may be used to
check out the radio set and isolate faulty
microphone circuitry.

(5)

HAVE QUICK mode (RT-1167C/

ARC-164(V) only).

The HAVE QUICK mode can be activated in

one of two ways:

(a)

Set MANUAL-PRESET-GUARD switch

to MANUAL and set frequency selector switch 1 to A.

(b)

Set MANUAL-PRESET-GUARD switch

to PRESET and set preset channel selector switch to
channel 20.

b. HAVE QUICK System Operation.

(1)

A 3-2-T Knob (HAVE QUICK System Only).

A - Selects AJ mode.

3 - Allows manual selection of frequencies.

2 - Allows manual selection of frequencies.

T - Momentary position which enables the
radio to accept a new TOD for up to 60 sec-
onds after selection. Also used in conjunc-
tion with the emergency startup of the TOD
clock when TOD is not available from a ex-
ternal source.

(2) TONE Button (HAVE QUICK). Depressing

the TONE button in normal or AJ modes interrupts re-
ception and transmits a tone signal and TOD on the
selected frequency. Simultaneously pressing the TONE
button in conjunction with the A-3-2-T knob in the T
position starts the emergency startup of the TOD clock.

(3) HAVE QUICK System. The HAVE QUICK

(HQ) system provides a jam resistant capability through
a frequency hopping technique. Frequency hopping is
a technique in which the frequency being used for a
given channel is automatically changed at some rate
common to the transmitter and receiver. The jam resist-
ance of the system is due to the automatic frequency
changing and the pseudorandom pattern of frequencies

used. In order to defeat this communications system,
the jammer must find the frequency being used, jam it
and then predict or find the next frequency. The HAVE
QUICK modification adds the frequency hopping capa-
bility, yet it does not remove any of the previous capabili-
ties of the radio. The HAVE QUICK modified radios
retain the standard, single frequency UHF voice mode
of operations. This is referred to as the normal mode,
while frequency hopping operation is called the anti-jam
(AJ) mode. Several ingredients are necessary for suc-
cessful system operations. These are:

Common frequency.

Time synchronization.

Common hopping pattern and rate.

Common net number.

The common frequencies have been programmed into
all HAVE QUICK radios. Time synchronization is pro-
vided via UHF radio and/or hardware by external time
distribution system. A time-of-day (TOD) signal must be
received from the time distribution system for each time
the radio is turned on. The hopping pattern and hopping
rate are determined by the operator inserted word-of-
day (WOD). The WOD is a multi-digit code, common
worldwide to all HAVE QUICK users. In the AJ mode, a
communications channel is defined by a net number
instead of a signal frequency as in the normal mode. Be-
fore operating in the AJ mode, the radio must be primed.
This consists of setting the WOD, TOD, and net number.
The AJ mode is then selected by placing the A-3-2-T
knob to A.

(4) WORD OF DAY (WOD). The WOD entry is

normally entered before flight, but it is possible to enter
it in flight. WOD is entered by using one or more of the
six preset channels which are 20-15. For a new WOD
entry, start at channel 20 use the same method as in
entering preset frequencies in the normal mode with the
frequency knobs and the PRESET button. After each
entry, a single beep is heard until channel 15 entry; a
double beep is heard indicating that the radio has ac-
cepted all six WOD entries.

(5) WOD TRANSFER. Select the preset mode

and, starting with present channel 20, rotate the preset
knob CCW. At channel 20, a single beep is heard. A
single beep indicates that channel 20 data has been
transferred and accepted. After the single beep is heard,
select remaining channels (19-15) in the same manner
until a double beep is heard indicating the WOD transfer
is complete.

(6) TIME-OF-DAY (TOD) Transmission. The

TOD entry is normally entered before flight, but it is
possible to enter it in flight. It is possible to transmit
timing information in both normal and AJ modes by mo-
mentarily pressing the TONE button. In the normal