Deep Dive: T8A10
The correct answer is B: About 6 MHz. The approximate bandwidth of AM fast-scan TV transmissions is about 6 MHz. Fast-scan TV (FSTV) is similar to broadcast TV and requires significant bandwidth to carry the video and audio information. The 6 MHz bandwidth accommodates the video signal, audio subcarrier, and necessary guard bands. For amateur radio operators, fast-scan TV is used on UHF bands where sufficient bandwidth is available. Understanding this large bandwidth requirement explains why TV is only practical on certain bands with adequate spectrum.
Why Other Answers Are Wrong
Option A: Incorrect. More than 10 MHz is wider than typical fast-scan TV. Standard FSTV uses about 6 MHz, similar to broadcast TV channels. Option C: Incorrect. About 3 MHz is too narrow for fast-scan TV - that's more like slow-scan TV bandwidth. Fast-scan needs about 6 MHz. Option D: Incorrect. About 1 MHz is far too narrow - that's SSB bandwidth. Fast-scan TV needs much more bandwidth for video.
Exam Tip
AM fast-scan TV = about 6 MHz. Think 'T'V = 'T'akes 'V'ideo bandwidth (~6 MHz). Fast-scan TV needs wide bandwidth for video and audio, similar to broadcast TV channels. Much wider than voice modes.
Memory Aid
AM fast-scan TV = about 6 MHz. Think 'T'V = 'T'akes 'V'ideo bandwidth (~6 MHz). Wide bandwidth needed for full-motion video and audio. Standard for fast-scan TV operation.
Real-World Example
Amateur fast-scan TV on 70 cm uses about 6 MHz of bandwidth - similar to broadcast TV channels. This wide bandwidth carries the video signal, audio, and sync information needed for full-motion video. The large bandwidth requirement limits fast-scan TV to UHF bands where sufficient spectrum is available.
Source & Coverage
Question Pool: 2022-2026 Question Pool
Subelement: T8A
Reference: 2022-2026 Question Pool · T8 - Signals and emissions
Key Concepts
Verified Content
Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T8A topic.