Single Side Band (SSB) — visualization & envelope-detection demo

Message (1 kHz tone or your mic) → full AM (carrier + both sidebands) → SSB (carrier & lower sideband suppressed). Then we try to envelope-detect each: AM recovers the message; SSB can't be — a tone goes silent, voice comes out garbled.

1 · Input (message) waveform

2 · Full AM — amber = envelope (1 + m·s)

3 · SSB (upper sideband only)

For a single tone, SSB is just one shifted sine — constant amplitude, no envelope to detect. For voice, the envelope no longer matches the message.

AM spectrum

SSB spectrum

4 · Recovering SSB — AM-decoder attempt vs proper receiver (carrier re-injected)

Envelope detection (AM decoder) gives the wrong signal; re-injecting the carrier (product detection) reconstructs the original. Try the BFO offset slider — a mistuned carrier shifts every frequency (the “Donald Duck” effect).