Variable Frequency
AP300 Series
Band Pass - Band Reject Filter/Amplifier

Model AP300

Simultaneous Bandpass and Band Reject output for any input signal in the frequency range of 0.1 Hz to 10,000 Hz. Both frequency and bandwidth can be varied continuously. Units can be cascaded for staggered filtering effects. The Bandpass Function. The filter singles out any particular band of frequencies. Gain is preserved at the center frequency of the passband over the complete frequency and bandwidth ranges. A preamplifier stage makes it possible to use the Bandpass output as a tuned amplifier. The Band Reject Function. The filter rejects any particular band of frequencies. Constant gain is preserved throughout the passband over the complete frequency and bandwidth ranges. A large attenuation is provided at the center frequency of the reject band. Maximum Band Reject effect is achieved by adjusting the Null adjust. The preamplifier stage enables unusually low level signal rejection. The Notch Gain Amplifier permits the adjustment of the signal level output independently of the Bandpass Function output.

Noise reduction in signal processing. Rejection of carrier modulation or line frequency interferences, spectrum analysis.

Sound, Vibration, Physiological measurements. Signal conditioning prior to computer processing.

Features include:

  • One potentiometer sweeps one frequency decade (total coverage up to 5 decades)
  • Fine frequency adjustment
  • One potentiometer controls Q (Bandwidth)
  • Input amplifier with variable gain up to x 100 to place signal in optimum dynamic range
  • Input signal range from 10 microvolts
    to ±12 Volt peak
  • Zero phase shift at center frequency
  • Output D.C. adjustment for zero offset
  • Simultaneous Band Reject and Band Pass outputs
  • $695.00 EACH


Q (Bandwidth) range 2­100 (50-%-1%)
Maximum Gain x 100
Maximum Voltage swing at output ±10 volt peak
Dynamic range 90 dB typical 80 dB min.
Response 2 pole
Band Pass Center frequency gain variation 2 dB (Q=5­40)
Band Reject center frequency attenuation
irrespective of null adjust 30 dB
with optimal null adjust 60 dB minimum
Noise level (to 100 kHz) 100 microvolts RMS
Input Resistance 2 Megohms
Output Resistance 25 ohms
Minimum load resistance 3 kOhms
Operating temperature 0°­70°C
Power 110 Volt 50­60Hz
220 Volt upon request
Terminals BNC
Dimensions 7" x 5"D x 4" H
Weight 3.0 lbs., 1.5 kg.

| About Us | Product Index |

Avens, Inc.
P.O. Box 518 Plumsteadville, PA 18949
Tel: 215-766-8775