TM 11-5820-890-10-3
SECTION III. TECHNICAL PRINCIPLES OF OPERATION
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Scope ............................................................................................................................................................................... 1-15
General Description.......................................................................................................................................................... 1-15
Functional Description...................................................................................................................................................... 1-15
SCOPE
This section describes the various configurations of SINCGARS radio equipment. It lists the types of data you need to
perform SC and FH operations and in which channel it must be loaded. It also describes why particular data is needed.
GENERAL DESCRIPTION
The MP, SR, SR-D, SR/LRA, SR/LR-D, LR, and LR/LR (AN/PRC-119 and AN/VRC-87, 88, 89, 90, 91, and 92) are radios
in a family of VHF-FM combat net radios designed to provide the primary means of command and control (voice and
digital data) for combat, combat service, and combat service support units. The radios are designed to achieve
commonality among the various configurations. A common receiver- transmitter (RT) is used in the manpack and in all
vehicular configurations.
FUNCTIONAL DESCRIPTION
Your SINCGARS radio is capable of two modes of operation: Single channel (SC) and frequency hopping (FH).
SINGLE CHANNEL: When using the SC mode of operation, the RT communicates on one frequency (selected using RT
keyboard) that has been loaded into the RT. The SC frequency can be cleared or offset as desired.
FREQUENCY HOPPING: SINCGARS also has the ability to secure transmissions through the use of a transmission
security key and frequency hopping to reduce or eliminate the threat of jamming and direction-finding equipment. In order
for your RT to use the FH mode of operation, it must be loaded with FH data. The data necessary for FH operation are (1)
TRANSEC variable, (2) SC frequency loaded into MAN channel, (3) hopset(s), (4) lockout set(s), if required, and (5) FH
sync time.
1. TRANSEC variable. The same variable is used by each RT in a FH radio net. An ECCM fill device or tape
reader is used to load It into the RT.
2. SC frequency loaded into MAN channel. When preparing for a cold start net opening, the net communicates
using the SC frequency loaded Into the MAN channel.
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