Click a packet in the feed, or a station on the map, to inspect it here — every byte explained against the spec, plus the modem waveform and a guided tour.
Live signal
The raw DSP inside the modem, straight from your audio input: the two AFSK tone envelopes (1200 Hz mark vs 2200 Hz space), the discriminator that decides each bit, and a marker at every decoded packet.
Click Use radio / mic to watch the signal live. Demo and file decoding happen instantly, so they don't produce a live waveform.
1200 Hz mark
2200 Hz space
discriminator
carrier detect
decode
bad CRC