Definition
A piece of electronic test equipment used to follow an electrical signal through the various stages of a circuit, such as a radio or amplifier, in order to locate the point at which the signal is lost, distorted, or weakened. The technician applies a known signal to the input and uses the tracer to listen to or display that signal at successive points in the circuit until the faulty stage is identified.
Plain English
A test tool that lets a technician follow a signal step-by-step through a circuit to find the exact spot where it stops working properly.
Context Anchor
Seen in aircraft electrical and electronic troubleshooting, especially when checking radios, intercoms, audio panels, or navigation receivers.
Derivation
From 'trace,' meaning to follow a path or track. The instrument literally traces where a signal goes — and where it stops going — through a circuit.
Why Pilots Care
Speeds up diagnosis of avionics faults so radios and navigation systems are returned to service quickly and reliably.
Analogy
Like walking along a garden hose listening for where the water stops flowing — you check each section in turn until you find the kink or break.
Intuition Check
A signal tracer does not create the signal or repair the circuit by itself. It helps locate the point where the existing signal is lost, weakened, or changed.
Example Sentence 1
The avionics technician used a signal tracer to find the failed stage in the aircraft's communication radio.
Example Sentence 2
Using the signal tracer on the localizer receiver, the mechanic located the stage where the signal disappeared and replaced the faulty module.