Deep Dive: T4A08
The correct answer is D: Flat copper strap. Flat copper strap is preferred for bonding at RF (radio frequency) because it has low inductance and provides a good RF ground connection. The flat, wide shape minimizes inductance, which is important at RF frequencies where inductive reactance can be significant. At RF frequencies, even small amounts of inductance can create significant impedance. Round wires have more inductance than flat straps of the same cross-sectional area. Flat copper strap provides a low-inductance path for RF currents, making it ideal for bonding equipment, grounding, and creating RF ground connections. The wide, flat shape keeps inductance low, ensuring good RF performance.
Why Other Answers Are Wrong
Option A: Incorrect. Copper braid from coaxial cable can work but isn't as good as flat strap. Braid can have higher inductance and isn't designed for bonding. Option B: Incorrect. Steel wire has higher resistance than copper and isn't ideal for RF bonding. Copper is much better for RF applications. Option C: Incorrect. Twisted-pair cable has significant inductance due to the twisting and isn't suitable for RF bonding. Flat strap is much better.
Exam Tip
RF bonding = Flat copper strap. Remember: Flat copper strap is preferred for RF bonding because its wide, flat shape minimizes inductance, which is critical at RF frequencies.
Memory Aid
**R**F **B**onding = **F**lat **C**opper (think 'RB = FC' = Flat Copper strap)
Real-World Example
You're bonding all your station equipment together for a good RF ground. You use flat copper strap (1 inch wide, 0.025 inch thick) to connect your transceiver, tuner, and other equipment to a common ground point. The flat strap provides a low-inductance path for RF currents, ensuring good RF grounding. This is much better than using round wire, which would have more inductance and poorer RF performance.
Source & Coverage
Question Pool: 2022-2026 Question Pool
Subelement: T4A
Reference: FCC Part 97.3
Key Concepts
Verified Content
Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T4A topic.