Razor-sharp CW filter


Posted on Feb 20, 2013

The circuit consists of four stages of active bandpass filtering provided by two type-µ integrated-circuit dual op amps and includes a simple threshold detector (diodes Dl and D2) between stages 2 and 3 to reduce low-level background noise. Each of the four filter stages acts as a narrow bandpass filter with an audio bandpass centered at 750 Hz.


Razor-sharp CW filter
Click here to download the full size of the above Circuit.

The actual measured 3-dB bandwidth is only 80 Hz wide.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Ac Watts Calculator Circuit
Bedside Lamp Timers
designing a phantom antenna power supply system
Homebrew Utrasonic Imager
Relation to Classic Oscillator Theory
Sound Effects Generator 2 circuit
Alternately flashing one of a plurality of sets of high-power lights a chain circuit



Top