Deep Dive: E3B05
The correct answer is D: A path entirely in darkness. Which of the following paths is most likely to support long-distance propagation on 160 meters is a path entirely in darkness. 160 meters works best when the entire path is in darkness (no sun). For amateur radio operators, this is important for 160-meter operation. Understanding this helps when operating on 160 meters.
Why Other Answers Are Wrong
Option A: Incorrect. Path entirely in sunlight doesn't work well - 160 meters needs darkness. Sunlight path is wrong. Option B: Incorrect. Paths at high latitudes isn't the key factor - darkness is the key factor. High latitudes isn't the answer. Option C: Incorrect. Direct north-south path isn't the key factor - darkness is the key factor. North-south path isn't the answer.
Exam Tip
160m long-distance propagation = path entirely in darkness. Think '1'60m = 'D'arkness needed. 160 meters works best when the entire path is in darkness. Not sunlight, not high latitudes, not north-south - just darkness.
Memory Aid
160m long-distance propagation = path entirely in darkness. Think '1'60m = 'D'arkness. 160 meters works best when the entire path is in darkness. Important for 160-meter operation.
Real-World Example
Long-distance propagation on 160 meters: A path entirely in darkness is most likely to support it. 160 meters is absorbed by the D layer during daylight, so darkness is essential. When the entire path is in darkness, absorption is minimal and signals can propagate long distances. This is the path - entirely in darkness.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E3B
Reference: 2024-2028 Question Pool · E3 - Radio Wave Propagation
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E3B topic.