What are the boxes in a station diagram, and what does each one do?
A schematic shows every component. A block diagram shows the big picture: boxes joined by arrows.
The diagram
A Practical circuit diagram (also called a block diagram) is a diagram using blocks to show signal flow and how the components of a system are connected. Each box is a function, not a single part.
The blocks
| Block | What it does |
|---|---|
| Transmitter | Generates and sends out radio-frequency signals |
| Receiver | Detects and processes incoming radio-frequency signals |
| Transceiver | A transmitter and receiver combined in a single unit |
| Telegraph key | Sends Morse code by opening and closing a circuit to make dots and dashes |
| Microphone | Converts sound waves (speech) into electrical signals |
| Modem | Modulates and demodulates signals, typically to send digital data over radio or analogue lines |
| Antenna switch | Switches an antenna between pieces of equipment (such as transmitter and receiver) or between antennas |
| Antenna | Converts electrical signals into electromagnetic waves for transmission, and the reverse for reception |
A Modem is short for modulator-demodulator.
Two supporting blocks
- TR switch: a transmit/receive switch. It connects the antenna to the transmitter while transmitting and to the receiver while receiving.
- Dummy antenna (dummy load): a resistor that absorbs the transmitter's power without radiating, for testing.
You now know
- A block diagram uses blocks to show signal flow and how a system's parts connect.
- Transmitters send RF, receivers detect it, and a transceiver is both in one unit.
- A key sends Morse, a microphone turns speech into electrical signals, and a modem modulates and demodulates data.
- The TR switch shares one antenna between transmit and receive; a dummy antenna absorbs power without radiating.