USArmy-ApacheLongbow

TM 1-1520-251-10
Section IIA. HF COMMUNICATIONS SUBSYSTEM
3.53A INTRODUCTION
This section covers the description and operation of the
aircraft communication subsystem and the Transponder/
IFF subsystem (fig 3-62A). Both voice and digital communications
are supported by the following equipment:
• ARC-186(V) VHF-AM Radio Set
• ARC-164(V) UHF-AM Radio Set (HAVEQUICK)
• TSEC/KY-58 (CIPHER DEVICE)
• ARC-201D VHF-FM (SINCGARS) 2 each
• IFM-101A/AM-7189A/ARC Improved FM (IFM)
Amplifier
• ARC-220 HF Radio Set
• TSEC/KY-100 (HF CIPHER DEVICE)
• APX-100(V) Transponder
• APX-118(V) Transponder
• MD-1295/A Improved Data Modem (IDM)
or
• Load Maintenance Panel (LMP) (COMSEC)
NOTE
The APX-100(V) Transponder or
APX-118(V) may be installed. If
APX-100(V) is installed, Kit-1C computer
must be installed for Mode 4 operation.
Each crewstation provides the crew with independent
control and status monitoring of the communication subsystem
via the Multi-Purpose Display (MPD), Up Front
Display (UFD) or Enhanced Up Front Display (EUFD),
and Keyboard Unit (KU). In addition, monitor select and
volume/squelch controls for each of the five radios are
controlled by the COMM panel in each crewstation. The
communication subsystem equipment is powered from
the battery bus and defaulted to ON when power is applied.
However crew control of the radios is limited until
aircraft or external power is applied. After aircraft power
has been applied to the MPDs, rapid initialization of the
radio presets and Signal Operating Instructions (SOI) can
be accomplished via the Data Transfer Unit (DTU).
SYSTEM
PROCESSOR 2
AM1789A/ARC
IMPROVED FM
AMPLIFIER
ARC−186
VHF−AM RADIO
ARC−201D (FM2)
VHF−FM RADIO
HF POWER AMPLIFIER
COUPLER
DATA TRANSFER
UNIT
ARC−201D (FM1)
VHF−FM RADIO
ARC220 HF RADIO
DISPLAY
PROCESSOR 2
COMMUNICATION
INTERFACE
UNIT (CIU)
KY−58/TSEC
PROCESSOR
SECURE VOICE
ARC−164
UHF−AM RADIO
KY−100/TSEC
PROCESSOR
SECURE VOICE / DATA
SYSTEM
PROCESSOR 1
MD1295/A
IMPROVED DATA
MODEM (IDM)
DISPLAY
PROCESSOR 1
KIT−1C/TSEC
TRANSPONDER
COMPUTER (WITH APX100)
APX−100(V) OR APX118(V)
IFF TRANSPONDER
LBA5080A
Figure 3-62A.
Communications Subsystem
Use or disclosure of this information is subject to the restriction(s) on the title page of this document.
Change 3 3-66.1