🔍 Key Concepts

• Negative resistance behavior in electronic tubes • How a tetrode tube differs from a diode and triode • Basic types of RF (radio frequency) oscillators used in maritime and communications equipment

💭 Think About

• Which of these choices is specifically associated with operation based on a negative resistance region of a vacuum tube? • Which options describe common RF oscillator tube types, and which are not actually standard recognized types? • Does any answer choice represent a simple detector or circuit function rather than a specialized oscillator device?

✅ Before You Answer

• Verify which device types are historically known vacuum-tube oscillators (not detectors). • Confirm which tube type or device is commonly described in textbooks as using negative resistance for oscillation. • Check whether any of the names in the options are not standard, widely recognized electronic components.