FCC Question Pool Review

Technician Class (Element 2) • 2022-2026

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Question T8D06

From subelement T8 - T8D

T8D06
Answer: B

What does the abbreviation "PSK" mean?

APulse Shift Keying
BPhase Shift Keying
CPacket Short Keying
DPhased Slide Keying

Why is this correct?

PSK stands for Phase Shift Keying, a digital modulation method that encodes data by shifting the phase of a carrier signal. PSK31, a popular amateur radio digital mode, uses this technique at 31 baud with only 31 Hz bandwidth. The incorrect options are made-up terms: 'Pulse Shift Keying' doesn't exist in radio terminology, 'Packet Short Keying' confuses PSK with packet radio protocols, and 'Phased Slide Keying' is fabricated jargon.

Memory tip

Digital mode abbreviations in amateur radio typically describe the modulation method: PSK (phase), FSK (frequency), ASK (amplitude). When you see 'shift keying' terms, focus on what's being shifted—phase, frequency, or amplitude. This pattern helps identify legitimate modulation types versus distractors.

Learn more

PSK31's narrow 31 Hz bandwidth allows multiple simultaneous conversations in the space of one voice signal, making it ideal for keyboard-to-keyboard contacts during band conditions that won't support voice. The phase modulation creates distinct signal states that digital signal processing can reliably decode even at very low signal levels, which is why PSK modes excel for weak-signal work and emergency communications where spectrum efficiency matters.

Think about it

Why do you think phase shift keying would be more resistant to noise and interference compared to amplitude-based digital modes?