Deep Dive: T9B01
The correct answer is B: Reduced signal loss. A benefit of low SWR is reduced signal loss. When SWR is low (close to 1:1), most of the transmitter power is transferred to the antenna with minimal reflection. High SWR causes significant power reflection, which means less power reaches the antenna and more is lost in the feed line. For amateur radio operators, low SWR ensures maximum power transfer and efficient operation. Understanding this helps explain why antenna tuning is important and why low SWR is desirable.
Why Other Answers Are Wrong
Option A: Incorrect. Low SWR doesn't directly reduce TV interference - that's controlled by filtering and proper station setup. SWR affects power transfer, not interference. Option C: Incorrect. Low SWR doesn't reduce antenna wear - antennas don't 'wear' from SWR. Physical damage comes from weather and mechanical stress, not SWR. Option D: Incorrect. Since A and C are not benefits of low SWR, 'all of the above' cannot be correct. Only reduced signal loss is a direct benefit.
Exam Tip
Low SWR benefit = reduced signal loss. Think 'L'ow 'S'WR = 'L'ess 'S'ignal loss. More power transfers to antenna, less is reflected and lost. Not about TV interference or antenna wear.
Memory Aid
Low SWR benefit = reduced signal loss. Think 'L'ow 'S'WR = 'L'ess 'S'ignal loss. More power transfers to antenna, less reflection. Ensures efficient power transfer.
Real-World Example
Your antenna has 1.5:1 SWR. About 96% of your 100-watt transmitter power reaches the antenna, with only 4% lost to reflections. If SWR were 3:1, only about 75% would reach the antenna, with 25% lost. Low SWR means more of your power is actually radiated, improving your signal strength.
Source & Coverage
Question Pool: 2022-2026 Question Pool
Subelement: T9B
Reference: 2022-2026 Question Pool · T9 - Antennas and feed lines
Key Concepts
Verified Content
Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T9B topic.