Deep Dive: E1A02
The correct answer is D: 3 kHz above the lower band edge. When using a transceiver that displays the carrier frequency of phone signals, the displayed frequency that represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band is 3 kHz above the lower band edge. LSB extends 3 kHz below the carrier, so carrier must be at least 3 kHz above lower band edge. For amateur radio operators, this is important for band compliance. Understanding this helps ensure legal operation.
Why Other Answers Are Wrong
Option A: Incorrect. Exact lower band edge isn't enough - LSB extends 3 kHz below carrier, so carrier must be 3 kHz above edge. Exact edge is too low. Option B: Incorrect. 300 Hz above isn't enough - LSB extends 3 kHz below carrier, so carrier must be 3 kHz above edge. 300 Hz is too low. Option C: Incorrect. 1 kHz above isn't enough - LSB extends 3 kHz below carrier, so carrier must be 3 kHz above edge. 1 kHz is too low.
Exam Tip
LSB carrier minimum = 3 kHz above lower band edge. Think 'L'SB = 'L'ower 'S'ideband extends '3' kHz below carrier. LSB extends 3 kHz below carrier, so carrier must be at least 3 kHz above lower band edge. Not exact edge, not 300 Hz, not 1 kHz - just 3 kHz above.
Memory Aid
LSB carrier minimum = 3 kHz above lower band edge. Think 'L'SB = '3' kHz below carrier. LSB extends 3 kHz below carrier, so carrier must be at least 3 kHz above lower band edge. Important for band compliance.
Real-World Example
A properly adjusted LSB emission: The lower sideband extends 3 kHz below the carrier frequency. If the lower band edge is 3.800 MHz, the carrier must be at least 3.803 MHz (3 kHz above) so the lower sideband (down to 3.800 MHz) stays within the band. 3 kHz above the lower band edge is the minimum carrier frequency for LSB.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E1A
Reference: FCC Part 97.301
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E1A topic.