Deep Dive: E3B11
The correct answer is D: Between sunrise and sunset. At what time of day is sporadic-E propagation most likely to occur is between sunrise and sunset. Sporadic-E is most common during daylight hours. For amateur radio operators, this is important for sporadic-E operation. Understanding this helps when operating sporadic-E.
Why Other Answers Are Wrong
Option A: Incorrect. Between midnight and sunrise isn't when sporadic-E occurs - it's between sunrise and sunset. Midnight to sunrise is wrong. Option B: Incorrect. Between sunset and midnight isn't when sporadic-E occurs - it's between sunrise and sunset. Sunset to midnight is wrong. Option C: Incorrect. Between sunset and sunrise isn't when sporadic-E occurs - it's between sunrise and sunset. Sunset to sunrise is wrong.
Exam Tip
Sporadic-E time of day = between sunrise and sunset. Think 'S'poradic-'E' = 'S'unrise to 'E'vening (daylight). Sporadic-E is most common during daylight hours. Not midnight-sunrise, not sunset-midnight, not sunset-sunrise - just sunrise to sunset.
Memory Aid
Sporadic-E time of day = between sunrise and sunset. Think 'S'poradic-'E' = 'D'aylight. Sporadic-E is most common during daylight hours. Important for sporadic-E operation.
Real-World Example
Sporadic-E propagation: It's most likely to occur between sunrise and sunset (daylight hours). Sporadic-E activity is driven by solar heating of the E layer, so it's most active during the day. This is the time - between sunrise and sunset.
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.