Question
How can unwanted ringing and audio instability be prevented in an op-amp audio filter?
Answer Options
- A) Restrict both gain and Q
- B) Restrict gain but increase Q
- C) Restrict Q but increase gain
- D) Increase both gain and Q
Correct Answer: A
Explanation
An \text{op-amp} active audio filter, such as those used for enhancing \text{CW} or \text{SSB} signals, achieves high selectivity through a high Quality factor (Q). While a high Q is desired, if the gain and Q of the filter are set too high, the filter circuit itself can become unstable or start to oscillate (ringing) near the passband frequency.
Unwanted ringing and audio instability can be prevented in an \text{op-amp} audio filter by operating conservatively. The best practice is to restrict both gain and Q to moderate values that are well below the instability threshold of the \text{op-amp} used. This ensures stable operation and produces a clean audio output, even if it means slightly less selectivity than theoretically possible.
This topic was automatically created to facilitate community discussion about this exam question. Feel free to share study tips, memory tricks, or additional explanations!