UHF transceiver 164 STBY/NORMAL switch
(pedestal extension, fig. 2-12) - STBY.
Function select switch - MAIN or BOTH
position, as required.
If function selector is at MAIN setting, only the
normal UHF communications will be received.
If selector is at. BOTH position, emergency
communications on the guard channel and
normal UHF communications will both be
Transceiver operating procedure.
Transmitter-intercom selector switch (audio
control panel, fig. 3-1) - 3.
Microphone switch - Depress to transmit
Preset channel selection.
Function selector switch - MAIN.
Mode selector switch - PRE
Manual frequency selector switches - Set
frequency to be placed into memory.
Preset channel selector switch - Set desired
SET switch - Depress.
VOICE SECURITY SYSTEM TSEC/KY-58
(COMPLETE PROVISIONS ONLY).
Complete provisions only are provided for a TSEC/
KY-58 voice security system. This system provides
secure (ciphered) two-way voice communications for the
pilot and copilot in conjunction with the #1 UHF, VHF-
FM (SINC- GARS), and #2 (BU VOW) transceivers.
The system will be located in the left equipment rack
behind the pilot System circuits are protected by the
UHF, VHF-FM, and BU VOW circuit breakers on the
overhead circuit breaker panel (fig. 2-7).
BACK-UP VOICE ORDER WIRE (BU VOW)
A transceiver identical in type and performance to the
UHF transceiver (fig. 3-3) is located on the left
equipment rack, to serve as a back-up voice order wire.
The transceiver can only be controlled by the ASF/ACS.
Standby control is not available. The transceiver is
selected on the audio control panel (fig. 3-1) by
transmitter-intercom selector switch position number 5
and by radio audio monitor control number 5. This set
provides for secure communications through interfacing
with a voice security system. The back-up voice order
wire set is protected by the 7 1/2- ampere BU VOW
circuit breaker in the overhead circuit breaker panel (fig.
2-6). The back-up voice order wire shares an antenna
mounted on the aircraft belly with the transponder (fig.
VHF COMMUNICATIONS TRANSCEIVERS
communications on 1360 channels from 118.00 through
151.975 MHz, and are operated by two CIL_22
transceiver control units, located on the pedestal
extension (fig. 2-12).
The solid-state transceiver includes capture-effect
automatic squelch to help prevent missed radio calls,
plus audio leveling and response shaping to insure
audio quality. Transmitter sidetone comes from
detected transmitter signal, and is therefore a reliable
check of transmission quality. Each VHF transceiver is
placarded VHF # 1 or VHF # 2, located on the overhead
circuit breaker panel (fig. 2-7).
VHF Transceiver Operating Controls (VHF- 22B).
All operating controls for the transceivers are located on
the CTL22 transceiver control units and on the FMN/AM
extension, fig. 2-12).
Active frequency display. Displays the
active frequency (frequency to which the transceiver is
tuned) and diagnostic messages.
Transfer/memory switch. This switch is a
three-position spring-loaded toggle switch placarded
XFR/ MEM, which when held to the XFR position,
causes the preset frequency to be transferred up to the
active display and the transceiver to be returned. The
previously active frequency will become the new preset
frequency and will be displayed in the lower window.
When this switch is held to the MEM position, one of the
six stacked memory frequencies will be loaded into the
preset display. Successive pushes will cycle the six
Store switch. This switch, placarded STO,
allows up to six preset frequencies to be selected and
entered into the control unit's memory. After presetting
the frequency to be stored, push the STO switch The
upper window displays the channel number of available
memory (CH 1 through CH 6) while the lower window
continues to display the frequency to be stored. For
approximately 5 seconds, the MEM switch may be used
to advance through