ICOM IC-240 Schematic Diagram
This document presents the schematic diagram for the ICOM IC-240 radio transceiver. It details the internal electronic circuitry and component layout.
Overall Circuitry
The schematic is organized into various functional blocks, illustrating the complex interconnections of components such as transistors, resistors, capacitors, inductors, and integrated circuits (ICs).
Key Components and Units
- Transistors: Various types of transistors are depicted, indicating their role in amplification and switching within the circuit.
- Resistors (R): Represented by zigzag lines, with values indicated (e.g., R8 220Ω, R2 22KΩ).
- Capacitors (C): Shown as parallel lines, with values indicated (e.g., C1, C2).
- Inductors (L): Depicted as coils, with values indicated (e.g., L1, L2).
- Integrated Circuits (ICs): Labeled with numbers (e.g., IC1, IC2) and specific part numbers where visible (e.g., PMB01TC, PMB080).
- Diodes: Represented by a triangle with a line, indicating their directional conductivity.
- Connectors and Terminals: Various points for input/output signals and power are clearly marked.
Functional Blocks
- Duplex Control Circuit: This section, located on the left side of the diagram, appears to manage duplex operations. It utilizes several logic gates (ICs) and input/output lines (Px, Px, Px, Px, Dx, Dx).
- Tone Call Unit: Situated on the right, this unit is responsible for tone signaling. It includes a grid-like structure labeled 'DIAL' with numbered terminals (1-22) and associated circuitry.
Diagrammatic Representation
The schematic uses standard electronic symbols to represent components and their connections. Lines indicate electrical pathways, with junctions clearly marked. Components are labeled with their respective reference designators and values.
Specific sections of the diagram show detailed arrangements of transistors and ICs, illustrating their interconnections through resistors and capacitors to form functional circuits like amplifiers and logic gates.
Component Identification Example
For instance, a section might show an IC labeled 'IC8' connected to several resistors (e.g., R2 22KΩ) and capacitors, with input signals labeled 'Px' and output signals connecting to other parts of the circuit.
Dial and Tone Call Unit Detail
The 'DIAL' section consists of 22 numbered terminals. Adjacent to these terminals is a grid structure associated with the 'TONE CALL UNIT'. This suggests a system for selecting or controlling tone frequencies or call functions via the dial.
Power and Signal Flow
While not explicitly detailing power supply lines, the schematic implies signal flow through the interconnected components, enabling the transceiver's operation.
