signal tracer and injector


Posted on Feb 4, 2014

A simple test circuit to fault find audio and radio equipment. Can be used to inject a square wave signal, rich in harmonics, or used with headphones as an audio tracer. A single pole double throw sitch is used to switch between inject and trace modes. The diagram is drawn in trace mode, the earpiece being connected to the collector of thelast tra


signal tracer and injector
Click here to download the full size of the above Circuit.

nsistor. Both transistors are wired as emitter followers, providing high gain. DC blocking is provided by the 1n capacitor at the probe end, and the two stages are capacitively coupled. when the switch is thrown the opposite way (to the blue dot) both transistors are wired as an astable square wave generator. This provides enough harmonics from audio up to several hundred kilohertz and is useful for testing AM radio Receivers.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Morse Code with touch button (555)
Low voltage flasher
Lamp-flasher
filter Strange behavior from variable-gain amplifier
3volt fm transmitter for 88mhz
Fred Nachbaurs Theremax modifications
Board making technique
AVR Color Clock
Optocouplers and transistors of the bistable circuit diagram



Top