Tracer-receiver

Description: The tracer receiver is a stereo audio amplifier and detector circuit that operates at a frequency close to 1 kHz. Inductors L1 and L2 are hand-wound coils, each consisting of 200 turns of #26 wire on 2-inch ferrite cores, tuned to the operating frequency of the amplifier and detector. The strength of the received signal for each individual receiver is indicated by an LED. The audio output from the receiver is directed to a stereo headphone. This dual-receiver configuration aids in locating and tracking hidden wires or cables by providing a directional output that indicates the path of the cable.

The 1 kHz signal is captured by L1 and coupled to the input of operational amplifier U1A, which provides a gain of approximately 100 dB. The output from U1A is routed through volume-control potentiometer R7 to the input of U1B, which further amplifies the already enhanced signal by an additional 100 times. This results in a maximum gain of about 10,000 dB for the receiver. The output from U1B has two pathways: one path couples the signal through capacitor C9 and resistor R13 to connector J1, driving one channel of a stereo headphone. The second path directs the signal through a voltage doubling and detection circuit composed of diodes D1 and D2, capacitors C11 and C13, which converts the amplified 1 kHz signal into a DC voltage used to activate transistor Q1. When Q1 is engaged, LED1 lights up, indicating the presence of a received signal.

The schematic design of the tracer receiver circuit includes various components that work in tandem to achieve the desired functionality. The hand-wound inductors L1 and L2 are critical for tuning the circuit to the 1 kHz frequency, ensuring optimal signal reception. The operational amplifiers U1A and U1B are configured to provide high gain, with U1A serving as the initial amplifier and U1B as a secondary stage that significantly boosts the signal strength.

The volume control potentiometer R7 allows for user adjustment of the audio output level, providing flexibility in listening comfort. The dual output paths from U1B enable both audio monitoring through headphones and visual indication of signal strength via the LED, enhancing the usability of the device.

The voltage doubling circuit is essential for converting the amplified AC signal into a usable DC signal, which is necessary for driving the transistor Q1. This transistor acts as a switch that controls the LED indicator, providing a clear visual cue when a signal is detected. The integration of these components within the circuit allows for effective tracking and detection of hidden wiring, making the tracer receiver a valuable tool in various electronic applications.The tracer receiver is a stereo audio amplifier/detector circuit operating near 1 kHz. Inductors Ll and 12-hand-wound coils, consisting of 200 turns of #26 wire on 2-inch ferrite cores-are tunea to the operating frequency of the amplifier/detector. The received signal strength of each individual receiver is indicated by an LED. The audio output of the receiver is fed to a stereo headphone. That dual-receiver scheme helps in locating and tracking the hidden wire or cable by giving a directional output that indicates the cable"s path.

The 1-kHz signal is picked up by Ll and coupled to the input of op amp Ula, which provides a gain of about 100 dB. The output of op amp Ula is fed through volume-control potentiometer R7 to the input of Ulb, which magnifies the already amplified :;ignallOO times more.

That puts the maximum gain of the receiver at about 10,000 dB. The output of Ulb follows two paths: in the first path, the signal is couple through C9 and Rl3 to Jl, and is used to drive one half of a stereo headphone. In the other path, the signal is fed through a voltage doubling/detector circuit-consisting of Dl, D2, Cll, and Cl3-that converts the amplified 1-kHz signal to the de voltage that"s used to drive Ql.

When Ql is turned on, LEDllights, indicating a received signal.