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

AVR terminal for serial port
the modern firepower pinball project
prepaid energy meter at89s52
USB Power Injector For External Hard Drives
VHF FM Antenna Booster Circuit
Sine wave oscillator
Fill light indoor photography circuit



Top