Deep Dive: E1B01
The correct answer is D: An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted. What constitutes a spurious emission is an emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted. Spurious emissions are unwanted emissions that don't carry information. For amateur radio operators, this is important for transmitter compliance. Understanding this helps ensure legal operation.
Why Other Answers Are Wrong
Option A: Incorrect. Transmission without proper call sign isn't a spurious emission - it's a rules violation, not an emission type. Call sign violation isn't spurious. Option B: Incorrect. Signal to prevent detection isn't a spurious emission - it's intentional, not spurious. Intentional signal isn't spurious. Option C: Incorrect. Signal interfering with another station exceeding 40 dB below fundamental isn't the definition - spurious emissions are defined by being outside necessary bandwidth, not by interference level. Interference level isn't the definition.
Exam Tip
Spurious emission = emission outside necessary bandwidth that can be reduced/eliminated without affecting information. Think 'S'purious 'E'mission = 'S'ignal 'E'xtra (unwanted). Spurious emissions are unwanted emissions that don't carry information. Not call sign violation, not intentional signal, not interference level - just unwanted emission outside bandwidth.
Memory Aid
Spurious emission = emission outside necessary bandwidth that can be reduced/eliminated without affecting information. Think 'S'purious 'E'mission = 'S'ignal 'E'xtra. Spurious emissions are unwanted emissions that don't carry information. Important for transmitter compliance.
Real-World Example
A spurious emission: A transmitter produces a signal at 14.200 MHz (intended frequency) but also produces unwanted emissions at 14.400 MHz (harmonics or other spurious). The emission at 14.400 MHz is outside the necessary bandwidth and can be reduced or eliminated (with filters) without affecting the information transmitted. This is a spurious emission - unwanted emission outside necessary bandwidth.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E1B
Reference: FCC Part 97.307
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E1B topic.