HEADQUARTERS OH-58A, Technical Manual

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TM 55-1520-228-10
Change 11 3-35
(13) CLR key – Press.
(a) Enter day.
(b) ENT key – Press.
(c) TIME key – Press.
(d) CLR key – Press.
(e) Enter hour
(f) Enter minute
(g) ENT key – Press.
(14) FUNCTION selector switch – SQ OFF.
(15) MODE selector switch – FH.
(16) PRESET selector switch – 1.
(17) Establish communications.
c. Homing.
(1) MODE selector switch – HOM.
(2) Frequency – Select FM homing station fre-
quency using key pad as follows:
(a) FREQ key – Press.
(b) CLR key – Press.
(c) Key in desired frequency.
(d) STO/ENT key – Press.
(3) Observe homing information on the head-
ing-radio bearing indicator.
d. Retransmission.
NOTE
Frequencies must have a minimum of 5
MHz difference, such as 30.00 MHz and
35.00 MHz.
(1) Frequencies – Select (Both FM Sets).
(2) Communications – Establish with each facil-
ity by selecting number 1 position and then number 5
position on Transmit-Interphone selector.
(3) FUNCTION selector switch – RXMT (Both
FM Sets).
(4) FUNCTION selector switch – OFF.
e. Scanning.
The RT can scan up to eight preset SC frequencies. The
frequencies it can scan are the ones loaded into the
presets 1-6, MAN, and CUE. When a signal is found,
that channel is locked in. The RT display will show the
channel number, and you can listen and talk on that
channel. When the channel has been inactive for 2.5
seconds, scanning will begin again.
One of the presets can be selected to be the priority
preset. The priority preset is scanned more often. The
RT will transmit on the priority preset at any time just by
pressing the push-to-talk on the headset.
(1) Starting Scanning.
(a) Set RT switches: FUNCTION – SQ ON;
MODE – FH; PRESET – CUE. Set other switches as
needed.
(b) Press STO (Sto/ENT) button on RT.
The display reads “SCAN.”
(c) Press a number, 0-8. This tells the RT
which preset has priority (0 is MAN; 7 is CUE; 8 is no
priority).
(2) Transmitting on a Locked-in Preset. Press
push-to-talk and speak into headset. Do this within 2.5
seconds after traffic has stopped.
(3) Selecting a Preset for Transmission. Press
number for channel on radio set keyboard. Press push-
to-talk within 2.5 seconds after display shows preset
number.
(4) Cancelling a Preset from Scan Se quence
Press number for preset on radio set key board, then
press CLR. The priority preset cannot be cancelled.
The display changes to “CLR” and preset number.
Scanning begins. The cancelled preset will not lock in
again.
(5) Restoring a Cancelled Preset. Press num-
ber for the cancelled preset. The display will shows “CH”
and preset number. The preset is now back in the scan-
ning sequence.
(6) Starting Scanning While Locked on a Pre-
set. Press STO (Sto/ENT) button on radio set.
(7) Checking Frequency of Locked-in Pre-
set. Press FREQ pushbutton on radio set while channel
number is in display. The display changes to show fre-
quency.
(8) Stopping Scanning. Set radio set PRESET
switch to a different position.
3-75. ZEROIZE SWITCH.
a. Description. The zeroize switch provides the
ability to zeroize all special codes contained in the AN/
ARC-201, TSEC/KY-58, and TSEC/KIT-1A Computer
when activated. Power must be applied to aircraft in
order for the switch to function.