Updated: Dec 9, 2025 | Source: 2022-2026 Question Pool | Topic: T9B
T9B10T9B

What is the electrical difference between RG-58 and RG-213 coaxial cable?

Deep Dive: T9B10

The correct answer is C: RG-213 cable has less loss at a given frequency. The electrical difference between RG-58 and RG-213 coaxial cable is that RG-213 has less loss at a given frequency. RG-213 has a larger center conductor and overall diameter than RG-58, resulting in lower losses. RG-213 is better for longer runs and higher power applications. For amateur radio operators, understanding cable differences helps when selecting feed lines. RG-213 is a better choice when lower loss is needed, though it's larger and less flexible than RG-58.

Why Other Answers Are Wrong

Option A: Incorrect. There is a significant difference - RG-213 has lower loss and can handle more power than RG-58. They're not the same. Option B: Incorrect. RG-58 doesn't have two shields - it has a single braided shield. Some specialized cables have multiple shields, but not RG-58. Option D: Incorrect. RG-58 cannot handle higher power levels - RG-213 can handle more power due to its larger size. RG-58 is smaller and has lower power handling.

Exam Tip

RG-213 vs RG-58 = RG-213 has less loss. Think 'R'G-213 = 'R'educed loss (larger cable). RG-213 is bigger, has lower loss, handles more power. RG-58 is smaller, has more loss, handles less power.

Memory Aid

RG-213 vs RG-58 = RG-213 has less loss. Think 'R'G-213 = 'R'educed loss. Larger cable with lower loss and higher power handling. RG-58 is smaller with more loss.

Real-World Example

You need 100 feet of feed line for 2 meters. RG-58 might have 3 dB loss, while RG-213 has only 1.5 dB loss. The larger RG-213 delivers more power to your antenna. However, RG-213 is thicker and less flexible, making it harder to route. The trade-off is size/flexibility versus loss/power handling.

Source & Coverage

Question Pool: 2022-2026 Question Pool

Subelement: T9B

Reference: 2022-2026 Question Pool · T9 - Antennas and feed lines

Key Concepts

Coaxial cable comparison RG-58 vs RG-213 Cable losses Feed line selection

Verified Content

Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T9B topic.