Filter Circuits

• "A" Weighting Filter For Audio Measurements
  
• 136KHz bridged-T notch filter to reduce strength of the German utility station DCF39 on 138.83 kHz
  
• 29.85 MHZ bandpass filter schematic
  
• 29.85 MHZ notch filter schematic
  
• 3KHz low-pass filter plus audio amp (PDF)
  
• 440 Hertz Peaked Low Pass Audio Filter Experiments
  
• 45 to 90Hz hum filter
  
• 4th Order Butterworth filter schematic and calculator
  
• 'A' Weighting Filter For Audio Measurements
  
• Active bandpass filter with TDA2320A
  
• Active bandpass filters
  
• Analog Filters for Data Conversion (ADC filter)
  
• Bandpass and IF Filter Circuits
  
• Bandpass filters
  
• Biquad Active Bandpass Filter Schematic
  
• Chebyshev / Butterworth filters
  
• Collection of quartz crystal ladder filter circuit diagrams
  
• CW Filters
  
• CW filters
  
• Design of active filters with operational amplifiers (includes circuit and Java filter calculator)
  
• Digital signal processor (DSP) for radio communications
  
• Discrete Component Audio-Frequency RC Filters
  
• Filter Circuit for the Earthworm Seismic Data Acquisition System
  
• Filters for the RadioJove Receiver
  
• Galaxy Noise Filter
  
• Higher Order Analog Butterworth Filter Designs, includes on-line filter calculator
  
• LC filter design
  
• Low pass filter for subwoofer
  
• Low-pass active filter
  
• Matching Low Pass Filter for 136kHz transmitter
  
• Multiple Feedback Bandpass Filter
  
• Multiple Feedback Bandpass Filter
  
• Sallen-Key Active Butterworth High Pass Filter Calculator and circuit diagram
  
• Sallen-Key Active Butterworth Low Pass Filter Calculator and circuit diagram
  
• Sallen-Key Low Pass Filter Calculator (handles Butterworth filters, Bessel filters and Chebychev)
  
• Self-tune filter
  
• Self-tuning CW filter
  
• Series Notch Fliter Designer / Calculator (displays circuit diagram after calculation)
  
• SSB AF filter
  
• SSB AF filter