A signal tracer is an electronic test equipment used for monitoring audio signals and other electronic circuitry. It is a simple high gain, low noise audio amplifier.

Salient Features

• Tracer is a simple device and is mostly powered by battery.
• It generally includes an amplifier and a loudspeaker.
• The device is normally supplied with an optional diode detector, which helps in detecting amplitude-modulated signals.
• The diode detector is only sensitive to amplitude modulation but it can also be used for testing circuits that are normally used for other modulation schemes such as FM radios.
• The device is usually packaged into a small, hand-held test probe.
• Sophisticated signal tracers may display digital levels using LEDs or light emitting diodes.

Working of Signal Tracer

• At first a test signal is injected by the technician into the device that is to be tested.
• Then with the help of the signal tracer, the signal can be followed through various circuits of the radio receiver.
• As long as the signal is audible, the circuit is said to be working.
• The disappearance of the signal indicates the presence of fault in the circuit.

Uses & Applications

The tracer can be used for various purposes and finds application in the following areas:

• Repairing receivers and amplifiers
• Electronic Data Processing
• Audio systems
• Monitoring signals in electronic devices
• Testing high frequency modulated signals in antenna, RF amplifier, IF section of a receiver, etc.