A defective crystal in the AFC section will...

Question 1 / 27070f9shFwqLlVsGcYovCfOf

Question 1 of 27070f9shFwqLlVsGcYovCfOf

A defective crystal in the AFC section will cause:

Question 1 of 27070

A defective crystal in the AFC section will cause:

🔍 Key Concepts

• Automatic Frequency Control (AFC) function in marine radar • How a crystal-controlled oscillator affects radar receiver tuning and stability • Typical visual symptoms on the PPI (Plan Position Indicator) when receiver frequency or timing is unstable

💭 Think About

• Think about what happens to the radar display when the receiver frequency drifts off the correct frequency for the transmitted pulse. • Which of the listed display problems sounds most like a timing or sweep issue versus a frequency/locking issue? • Consider which option would be a persistent, systematic pattern on the whole screen, rather than an intermittent or localized effect.

✅ Before You Answer

• Review what the AFC section actually controls in a radar set (hint: receiver tuning and frequency stability). • Match each choice to a known radar display fault (e.g., sweep timing, interference, gain/clutter, or frequency instability). • Ask: would a bad AFC crystal more likely cause random clutter-like artifacts or a regular, repeating pattern on the PPI?

Question 1 of 27070

A defective crystal in the AFC section will cause:

No serious problems.

Bright flashing pie sections on the PPI.

Spiking on the PPI.

Vertical spikes that constantly move across the screen.