Which of the following is true of PL-259 type coax connectors?
The correct answer is C: They are commonly used at HF and VHF frequencies. PL-259 type coax connectors are commonly used at HF and VHF frequencies. PL-259 (plug) and SO-239 (socket) are the standard UHF connectors for amateur radio, providing good performance at HF and VHF. They're inexpensive, easy to install, and work well up to about 300 MHz. For amateur radio operators, PL-259 connectors are the most common type found on equipment and feed lines for HF and VHF operation. Understanding this helps when selecting connectors for different frequency ranges.
Exam Tip
PL-259 = commonly used at HF and VHF. Think 'P'L-259 = 'P'opular at 'L'ower frequencies (HF/VHF). Standard UHF connector for amateur radio. Not for microwave, not watertight, not bayonet-type.
Memory Aid
"PL-259 = commonly used at HF and VHF. Think 'P'L-259 = 'P'opular at 'L'ower frequencies. Standard UHF connector for HF and VHF amateur radio. Threaded connection, not bayonet."
Real-World Application
Your HF transceiver and 2-meter equipment use PL-259 connectors - they're the standard for amateur radio at these frequencies. They're easy to install, inexpensive, and provide good performance up to about 300 MHz. For 70 cm and higher frequencies, you'd use Type N connectors instead for better performance.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. PL-259 connectors are not preferred for microwave operation - they have poor performance above 400 MHz. Type N connectors are used for microwave.
Option B: Incorrect. PL-259 connectors are not watertight - they require sealing (tape, sealant) to prevent moisture entry. They're not inherently waterproof.
Option D: Incorrect. PL-259 connectors use threaded connections, not bayonet-type. Bayonet connectors (like BNC) use a twist-lock mechanism.
题目解析
The correct answer is C: They are commonly used at HF and VHF frequencies. PL-259 type coax connectors are commonly used at HF and VHF frequencies. PL-259 (plug) and SO-239 (socket) are the standard UHF connectors for amateur radio, providing good performance at HF and VHF. They're inexpensive, easy to install, and work well up to about 300 MHz. For amateur radio operators, PL-259 connectors are the most common type found on equipment and feed lines for HF and VHF operation. Understanding this helps when selecting connectors for different frequency ranges.
考试技巧
PL-259 = commonly used at HF and VHF. Think 'P'L-259 = 'P'opular at 'L'ower frequencies (HF/VHF). Standard UHF connector for amateur radio. Not for microwave, not watertight, not bayonet-type.
记忆口诀
PL-259 = commonly used at HF and VHF. Think 'P'L-259 = 'P'opular at 'L'ower frequencies. Standard UHF connector for HF and VHF amateur radio. Threaded connection, not bayonet.
实际应用示例
Your HF transceiver and 2-meter equipment use PL-259 connectors - they're the standard for amateur radio at these frequencies. They're easy to install, inexpensive, and provide good performance up to about 300 MHz. For 70 cm and higher frequencies, you'd use Type N connectors instead for better performance.
错误选项分析
Option A: Incorrect. PL-259 connectors are not preferred for microwave operation - they have poor performance above 400 MHz. Type N connectors are used for microwave. Option B: Incorrect. PL-259 connectors are not watertight - they require sealing (tape, sealant) to prevent moisture entry. They're not inherently waterproof. Option D: Incorrect. PL-259 connectors use threaded connections, not bayonet-type. Bayonet connectors (like BNC) use a twist-lock mechanism.
知识点
PL-259 connectors, UHF connectors, HF/VHF connectors, Connector types
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.