🔍 Key Concepts

• Oscillator circuits commonly used in RF (radio frequency) equipment • The difference between named oscillator types (like Colpitts, Hartley, Pierce) and general circuit concepts (like negative feedback) • Which names in the list are actually standard oscillator designs used in radio textbooks and FCC/USCG prep materials

💭 Think About

• Look at the choices and separate out any option that includes something that is not a standard, named oscillator type used in RF theory • Ask yourself which three names you most often see grouped together in basic radio theory: two are very common LC oscillators, and one is a common crystal oscillator • Eliminate any answer that mixes a specific circuit type with a broad design principle rather than three specific oscillator types

✅ Before You Answer

• Verify that all three items in your chosen answer are well‑known, specific oscillator circuit names from your study materials • Check that none of the three is just a general concept (like feedback) instead of a distinct oscillator circuit • Confirm that the three names you pick are typically associated with RF and crystal oscillators in marine/communications radio equipment