Can you identify the signal?

Test your radio signal identification skills with audio samples and waterfall displays from sigidwiki.com

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Daily Challenge

5 signals, same for everyone

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Practice

Unlimited rounds, learn at your pace

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Time Trial

How many can you get in 60 seconds?

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Story Mode

Learn modulations step by step

Story Mode

Learn modulations step by step with tutorials and short quizzes.

Stage 1: Fundamentals

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CW, AM, FM, and SSB basics.

4 Tutorials

Stage 2: Keying + FSK Basics

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OOK/ASK and common FSK patterns.

4 Tutorials

Stage 3: PSK Basics

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Recognize early PSK signals like PSK31.

4 Tutorials

Stage 4: Higher-Order Digital

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8PSK and QAM families.

4 Tutorials

Stage 5: Advanced Wideband

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OFDM, Spread Spectrum, and Pulse signals.

4 Tutorials

Stage 1: Fundamentals

Amplitude Modulation (AM)

Amplitude Modulation varies the strength of the carrier wave to encode audio information.

Visual Characteristics

  • Symmetrical sidebands appear on both sides of the carrier

Audio Hints

AM audio sounds natural but may have background hiss.

Example Audio

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🎵 Loading audio...

Example Waterfall

Example waterfall display
📊 Loading example...

Stage 1: Fundamentals · Test

Question 1 / 5

Round 1/5
Score 0
Streak 🔥 0
0:00 / 0:00
Signal waterfall/spectrogram
📊 No waterfall available
Frequency --
Location --
Bandwidth --
Mode --
Modulation --
Access --
Spreading --

Morse Code (CW)

Categories
Frequency Bands
Modulation
Bandwidth
Learn more on sigidwiki.com →

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