TM 11-5820-890-30-4
2-4.
ICOM I/O SECTION.
The ICOM I/O section consists of five modules. They are:
Circuit Card Assembly - ICOM Power Supply 1A12 (ICOM power supply)
Circuit Card Assembly - ICOM Control 1A13 (ICOM control module)
Circuit Card Assembly - ICOM Data I/O 1A14 (ICOM data I/O module)
Circuit Card Assembly - Fill Routing 1A15 (fill routing module)
Circuit Card Assembly - COMSEC 1A16 (COMSEC module)
The module locations are shown in figure 2-5.
Figure 2-5.
ICOM I/O Section Module Locations
All signals passing between the ICOM I/O section and the rest of the RT are filtered or buffered by the ICOM power
supply. These signals inside the ICOM I/O section are called RED signals to avoid confusion. The ICOM power
supply also adds the 150-Hz squelch tone to the audio or data signal to be transmitted.
The ICOM control module performs the following functions:
Generation of ICOM I/O section control signals.
Plain text/cipher text (PT/CT) signal routing.
Control of the push-to-talk line inside the ICOM
The ICOM data l/O module controls signal routing within the
and audio output amplifiers.
I/O section.
ICOM l/O section. It also contains the microphone
The fill routing module controls fill operations.
It routes fill information to the ECCM and COMSEC modules
depending on which variables are transferred.
During COMSEC operation this module routes signals to the
COMSEC module for ciphering and deciphering.
The COMSEC module performs all encryption and decryption of signals during COMSEC operation.
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