FD23 Feedback Detector
The FD23 feedback (ringing) detector is a self-sustaining and erroneous oscillation that occurs when sound arriving at a microphone is greater than the sound produced by the person or instrument using that microphone. Feedback is controlled through the use of a graphic or parametric equalizer, and these units are most effective when the sound engineer can quickly recognize the frequency at which feedback is occurring. The FD23 provides a quick inexpensive means of detecting which frequency is causing the feedback.
l When used with any equalizer, it is the fastest way to eliminate feedback.
l Uses the same filters as found in expensive 1/3 octave analyzers.
l A rugged hand held instrument with built-in microphone, powered by AA batteries or a 12Vdc supply.
Microphone: Omnidirectional electret condenser.
Measurement frequencies (Hz): 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1k, 1.25k, 1.6k, 2k, 2.5k, 3.15k, 4k, 5k, 6.3k, 8k, 10k, 12.5k.
Display: Individual LED for each channel (23) measured.
Power Requirements: Internal - Eight "AA" alkaline or nicad batteries.
  External - 12Vdc @ 200mA via 3.5mm jack.
Size (W x H x D): 3" x 8" x 2"
Weight: 12oz.
Case Material: High impact ABS
Approvals: CE, RoHS and WEEE
  Emissions: - EN 55022 B - FCC Class B
  Immunity: - EN 55024 B