Posted on Apr 19, 2012

The bug tracer is made up of a simple rf-injector circuit consisting of Ql and Q2, and a pocketsize, AM broadcast receiver. The two-transistor rf-injector circuit supplies a constant rf signal to one end of a cable. Then the AM receiver is used as a detector, allowing you to trace the wire to its source. Transistor Ql, along with piezoelectric ceramic resonator RESl, make up a simple rf oscillator that operates either at or near the AM-radio, 455-kHz, i-f frequency.

Click here to download the full size of the above Circuit.

That means that the second or third harmonic signal can easily be picked up by the receiver. Transistor Q2 is connected to an emitterfollower circuit to protect the oscillator from output loading; that helps to stabilize the output frequency and signal level.

Leave Comment

characters left:

New Circuits



Popular Circuits

Dual Regulated Power Supply 15v
60W power amplifier
Positive input-negative output charge pump
Voltage-To-Frequency Converter Ii
Ultimate Continuity Tester Hides Many Tricks Up Its Sleeve
wireless picaxe based water tank level sensor
active filters
Electronic toss circuit
just sanity check transformers
coilless FM transmitter circuit diagram
An Audible Field Strength Indicator for Radio Direction Finding
Pultec EQP1A Equalizer
Preamp using the current series feedback circuit