What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?
Removal of the CW signal as well as the interfering carrier✓Correct answer
Any nearby signal passing through the DSP system will overwhelm the desired signal
Excessive ringing
All these choices are correct
Explanation
An automatic notch filter looks for steady sinusoidal components in the passband and removes them, and an unmodulated CW carrier is exactly such a component. The filter has no way to tell a wanted CW signal from an interfering carrier, so it may notch out both.