(5) Kilohertz selector. Tunes transceiver in
(3) PLAIN indicator.
Illuminates when the
50-kHz, as indicated by the fourth frequency indicator.
PLAIN/CIPHER switch is in the PLAIN position.
(6) Mode selector.
(4) PLAIN/CIPHER switch. Controls unciphered
or ciphered communications.
(a) OFF. Turns set off.
Provides for transceiver
operation of frequency displayed on frequency indicator.
retransmission, or cipher/normal communications.
(d) HOME. Provides for operation in the
homing mode. May also be operated as a transceiver on
Permits retransmission of
channels indicated on frequency indicator.
(7) VOL control. Adjusts volume.
Permits normal cipher or
(8) SQUELCH switch. Controls squelch.
Disables receiver squelch
Do not place the ZEROIZE switch in
the ON position unless a crash or
Activates receiver squelch
capture is imminent.
(6) ZEROIZE switch.
Normally in OFF
(c) TONE. Not used in this installation.
Placed in ON position during emergency
situations to neutralize and make inoperative the
b. Operating Procedures. Refer to Voice Security
associated cipher equipment.
System operating procedures.
(7) CIPHER indicator. Illuminates when the
3-8. Voice Security System (TSEC/KY-28) (If installed).
PLAIN/CIPHER switch is in the CIPHER position.
a. Description. The voice security system is used in
c. Operating Procedures for FM Liaison Set and
conjunction with the FM liaison set to provide secure
Voice Security System.
Power for the voice security system is fed through the 50-
ampere AVIONICS NO. 1 and AVIONICS NO. 2 circuit
breakers on the copilot's circuit breaker panel. The voice
Disregard the operating procedures
security system is protected by a 10-ampere circuit
breaker, placarded FM, located on the copilot's subpanel.
(CIPHONY) control-indicator if this
unit is not installed.
b. Controls and Functions.
(1) POWER ON switch. Turns set on or off.
at a given position
Switch must be in the ON position for
UHF, VHF, or HF
FM liaison operations in either the
keyed from that
plain or cipher mode.
(2) POWER ON indicator. Illuminates when
(1) Turn-on procedure. POWER ON switch
the POWER ON switch is placed in the up (on) position.
(CIPHONY control-indicator) - ON.
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