Sufficient crosspatch capabilities were provided to permit any TD-1389 to function in any role. Baseband
patching is able to access all baseband ports on the shelter entry panels. This will allow the individual channels
of the CV-1548/MX-9635 to be patched into any user channel as required. In addition, two KG-27s were
replaced by one KG-94A to provide bulk encryption for one unstressed multichannel group. A non-nodal
terminal AJ/CM will be installed. This AJ/CM will provide an antijamming communications channel and
replace the FM control orderwire. One STU-III/equivalent will be added to the AN/TSC-93B to provide an
AJ/CM stress mode secure voice capability.
4. Differences. The main differences in tactical multichannel terminal configurations are the types and amount
of redundant equipment in the configuration and the terminal's communications capability. The equipment is
configured in either a nodal (hub) or non-nodal (spoke) configuration. A nodal terminal can be configured to
operate with up to four terminals in a multipoint operation. Any two terminals, either nodal or non-nodal, can
be configured to provide a point-to-point requirement.
LEARNING EVENT 6: ANTIJAMMING AND ECCM TECHNIQUES
1. AJ/CM is a family of spread-spectrum modem equipment designed to provide GMF TACSAT terminals
with an ECCM capability for operation in a stressed environment. The normal mode of operation for high
capacity links in a benign or nonstressed environment uses the current biphase shift keying/quadraphase shift
keying (BPSK/QPSK) modems and FDMA link accesses.
2. The family of modems consists of a network control terminal (NCT), a nodal terminal (NT), and a non-
nodal terminal (NNT). The AJ/CM provides a lower capacity 75 bp/s and 32 kb/s communications capability
and an antijamming control orderwire.
a. NCT modem. The AN/MSQ-114/FSQ-124 satellite control and monitoring systems use the NCT
modem. It is made up of two chassis assemblies-the MD-1133 and the OX-63 coder group.
(1) The MD-1133 network control unit (NCU) interfaces with the terminal frequency reference and
distributes time and frequency to the NCT internally. The NCU also provides the NCT modem
modulation/demodulation functions. User commands initialize and control NCU hardware elements to perform
major NCT operations or processing. The NCT contains bus logic to control an externally-programmable
downconverter. The NCT also provides modem and network status monitoring and provides status and
messages to the NCT operator.
(2) The OX-63 coder group, transmission security (TRANSEC), 4-channel unit houses four KGV-9
TRANSEC modules, associated interface circuits, and the necessary power supplies.
SS0031
5-10
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