🔍 Key Concepts

• Protection of DC meters from stray RF (radio-frequency) in a transmitter circuit • How RF chokes, bypass capacitors, and filtering keep RF off DC measuring circuits • Recognizing that the question asks about protection against damage, not transmitter malfunctions

💭 Think About

• Ask yourself: Which option(s) describe a method or component that would actually keep RF out of the meter circuit, rather than cause an operating fault? • Consider whether any of the listed items are normally used as filters or RF blocking devices on DC lines. • Think about what happens to a DC meter if RF current is allowed to flow through it—what kind of protective part would be placed in series or parallel to prevent that?

✅ Before You Answer

• Identify which choice, if any, is associated with an RF filtering or suppression function, not a biasing fault. • Separate items that describe problems in the bias/keying circuits from those that sound like intentional RF protection or filtering components. • Before picking "All of the above," verify that each individual item clearly provides RF protection to DC meters, not just general transmitter issues.