Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E2B
E2B06E2B

What is vestigial sideband modulation?

Deep Dive: E2B06

The correct answer is A: Amplitude modulation in which one complete sideband and a portion of the other are transmitted. What vestigial sideband modulation is amplitude modulation in which one complete sideband and a portion of the other are transmitted. Vestigial sideband transmits one full sideband and part of the other. For amateur radio operators, this is important for fast-scan TV operation. Understanding this helps when operating fast-scan TV.

Why Other Answers Are Wrong

Option B: Incorrect. Modulation in which one sideband is inverted isn't vestigial sideband - vestigial sideband transmits one full sideband and part of the other, not inverted. Inverted sideband isn't vestigial. Option C: Incorrect. Narrow-band FM with one sideband filtered isn't vestigial sideband - vestigial sideband is AM, not FM. FM isn't vestigial sideband. Option D: Incorrect. Spread spectrum with FM following SSB AM isn't vestigial sideband - vestigial sideband is AM with partial sideband, not spread spectrum. Spread spectrum isn't vestigial sideband.

Exam Tip

Vestigial sideband modulation = AM in which one complete sideband and portion of other are transmitted. Think 'V'estigial 'S'ideband = 'V'ideo 'S'ideband (one full, one partial). Vestigial sideband transmits one full sideband and part of the other. Not inverted, not FM, not spread spectrum - just AM with partial sideband.

Memory Aid

Vestigial sideband modulation = AM in which one complete sideband and portion of other are transmitted. Think 'V'estigial 'S'ideband = 'O'ne full, 'P'artial. Vestigial sideband transmits one full sideband and part of the other. Important for fast-scan TV operation.

Real-World Example

Vestigial sideband modulation: It's amplitude modulation in which one complete sideband and a portion of the other sideband are transmitted. For example, the upper sideband is transmitted completely, and a portion of the lower sideband (the vestige) is also transmitted. This is what vestigial sideband modulation is - AM with one full sideband and part of the other.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E2B

Reference: 2024-2028 Question Pool · E2 - Operating Procedures

Key Concepts

Vestigial sideband modulation Amplitude modulation One complete sideband Portion of other sideband

Verified Content

Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E2B topic.