Deep Dive: E3A11
The correct answer is B: 100 miles to 300 miles. What is a typical range for tropospheric duct propagation of microwave signals is 100 miles to 300 miles. Tropospheric ducts can extend microwave signals beyond the normal horizon. For amateur radio operators, this is important for microwave propagation. Understanding this helps when operating on microwave bands.
Why Other Answers Are Wrong
Option A (10-50 miles): Incorrect. 10-50 miles is too short - tropospheric ducts typically extend 100-300 miles. 10-50 miles is too short. Option C (1,200 miles): Incorrect. 1,200 miles is too long - tropospheric ducts typically extend 100-300 miles. 1,200 miles is too long. Option D (2,500 miles): Incorrect. 2,500 miles is way too long - tropospheric ducts typically extend 100-300 miles. 2,500 miles is too long.
Exam Tip
Tropospheric duct range = 100 miles to 300 miles. Think 'T'ropospheric 'D'uct = 'T'ypical 'D'istance 100-300 miles. Tropospheric ducts can extend microwave signals 100-300 miles. Not 10-50 miles, not 1,200 miles, not 2,500 miles - just 100-300 miles.
Memory Aid
Tropospheric duct range = 100 miles to 300 miles. Think 'T'ropospheric 'D'uct = '1'00-'3'00 miles. Tropospheric ducts can extend microwave signals 100-300 miles. Important for microwave propagation.
Real-World Example
Tropospheric duct propagation for microwave signals: A typical range is 100 miles to 300 miles. Ducts can extend signals well beyond the normal radio horizon. This is much longer than line-of-sight but shorter than ionospheric propagation. This is the range - 100 miles to 300 miles.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E3A
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 E3A topic.