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

Multiple-input-detector
74HC11 Infra-Red Remote Control Tester
Maximum Load Capacitor that LMV116 can drive
8 channel thermocouple based temperature data logger
Linearized platinum resistance thermometer
Two electric motors or electrical interlocking control circuit
lm358 alkaline battery charger circuit



Top