Which of the following indicates that gain is set to the appropriate level?

• A. A light background speckling
• B. A bright, solid line across the screen
• C. No speckling
• D. Excessive noise on screen

Answer: (A)

Radar gain being set at the right level shows up as a light, even speckling across the background of the display. This texture comes from a mixture of real weak echoes (like distant weather, sea clutter) and the receiver’s noise floor, meaning the system is amplifying enough to reveal small targets without washing everything out. If gain is too low, the screen would look almost clean or dark with little to no speckling, making faint echoes hard to see. If gain is too high, the screen becomes crowded with noise—excessive speckling that can obscure true targets. A bright, solid line across the screen isn’t typical of a proper gain setting; it usually indicates a strong single return or over-saturation. No speckling would point to under-gain.