TM 11-5820-890-30-4
2-1.
INTRODUCTION. Continued
The ICOM
The ICOM
I/O section provides:
The interface circuitry for audio and data input/output (I/O).
Audio/Data signal level control.
Enhanced data handling capability.
COMSEC encryption/decryption.
l/O section is described in paragraph 2-4.
The power supply converts the dc input voltage into the voltages required by the other modules in the RT. It is
described in paragraph 2-5.
The RT chassis includes:
The front panel with its switches, controls, connectors and displays.
The module interconnections.
Frame for physical support of the modules.
System and battery connectors.
It is described in paragraph 2-6.
A description of the types of signals present in
Paragraphs 2-8 through 2-21 provide functional
2-2.
CONTROL SECTION.
the RT is included in paragraph 2-7.
description of the RT in different modes of operation.
The control section consists of five modules. They are:
Electronic Components Assembly - Control 1A4 (control module).
Control, Counter-Countermeasures - Electronic 1A5 (ECCM module).
Circuit Card Assembly - Remote l/O 1A2 (remote l/O module).
Circuit Card Assembly - Two-Wire Interface 1A6 (two-wire interface).
Circuit Card Assembly - Switch 1A7 (switching module).
The module locations are shown in figure 2-3.
The control module contains a microprocessor and the programming used in single channel operation. Buffers,
registers, and interface circuits are included to permit the microprocessor to communicate with the other RT
modules. It checks the FCTN, MODE, RF, and CHAN switches and the keyboard for operator action. If the
operator’s actions are valid, the other modules and the front panel display are informed of any directed changes.
Control signals are described in paragraph 2-14.
The ECCM module contains another microprocessor and the programming used in frequency hopping operation.
The ECCM module has two connectors. One connects to the control module and the other to the RT chassis.
When the MODE switch is set to FH or the microprocessor in the control module executes instructions
in the ECCM module. It uses the hopset and lockout sets to build a look-up table of frequencies. The TRANSEC
variable, FH sync time (TOD), and net ID number are used to select a frequency from that table. When transmit-
ting, the ECCM module converts the analog signal into a digital data signal. The ECCM module microprocessor
interleaves the data signal onto the frequency hops.
When receiving, the process is reversed. Frequency
hopping operation is described in paragraph 2-15.
2-4
