TM 11-5821-333-30
CHAPTER 2
MAINTENANCE INSTRUCTIONS FOR RADIO RECEIVER-TRANSMITTER
RT-1476/ARC-201(V), RT-1477/ARC-201(V), RT-1478/ARC-201(V),
RT-1476A/ARC-201A(V),
RT-1477A/ARC-201A(V),
AND
RT-1478A/ARC-201A(V)
Section I. PRINCIPLES OF OPERATION
2-1. INFORMATION
The rt can be divided into five parts or functional sections.
l Control Section
l Rf Section
l Front Panel
l Power Supply
Rt Chassis
Figure 2-1 is an rt block diagram. It shows how the five sections are connected.
The control section contains the microprocessors, memory, and interface circuits that
l Scan the front panel for operator instructions
Send display data to the operator display
Select frequencies and tune the frequency synthesizer
Control signal routing between modules
Control optional IFM power amplifier
l Provide homing signals to homing indicator
l Provide interface to aircraft intercom
l Provide interface to data rate adapter
l Receive and store ECCM fill information
The control section is described in paragraph 2-2.
The rf section is digitally tuned by the control section. When receiving, it demodulates the rf signal. It routes
recovered audio or data to the control section, When transmitting, the rf section modulates a rf carrier with audio
or data, The rf section is described in paragraph 2-3.
For local control, the front panel is the operator control point. For remote control, the front panel is the interface
between the rt and the control unit. The front panel is described in paragraph 2-4.
The power supply converts the aircraft bus 28 V dc into the dc voltages required by the other rt modules. The
power supply is described in paragraph 2-5.
The rt chassis includes:
The module interconnections
l Frame for physical support of the modules
It is described in paragraph 2-6.
2-1
