Deep Dive: G9A02
The correct answer is B: High SWR increases loss in a lossy transmission line. The relationship between high standing wave ratio (SWR) and transmission line loss is that high SWR increases loss in a lossy transmission line. High SWR causes more current to flow (due to standing waves), increasing I²R losses. For amateur radio operators, this is why low SWR is important. Understanding this helps when evaluating feed line performance.
Why Other Answers Are Wrong
Option A: Incorrect. There is a relationship - high SWR increases loss in lossy lines. No relationship is wrong. Option C: Incorrect. High SWR doesn't make it difficult to measure loss - loss can still be measured. Measurement difficulty isn't the relationship. Option D: Incorrect. High SWR doesn't reduce the relative effect of loss - it increases loss. Loss reduction isn't the relationship.
Exam Tip
High SWR and loss = high SWR increases loss in lossy line. Think 'H'igh 'S'WR = 'H'igher 'S'tanding waves = 'H'igher 'L'oss. High SWR causes more current flow, increasing I²R losses. Not no relationship, not measurement difficulty, not loss reduction - just increases loss.
Memory Aid
High SWR and loss = high SWR increases loss in lossy line. Think 'H'igh 'S'WR = 'H'igher 'L'oss. High SWR causes more current flow, increasing I²R losses. Important reason to maintain low SWR.
Real-World Example
A lossy transmission line with high SWR: Standing waves cause higher current flow in some parts of the line. This increased current causes more I²R losses (power lost as heat). High SWR increases the loss in lossy transmission lines. This is why low SWR is important - it minimizes feed line losses.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G9A
Reference: 2023-2027 Question Pool · G9 - Antennas and Feed Lines
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G9A topic.