HzDrop
Ready
Send
Receive
Received history
Signal & protocol details
Spectrum · audio inactive
02.5 kHz5 kHz7.5 kHz10 kHz
- Microphone
- Not opened
- Input level
- —
- Link
- —
- Packets
- —
- Screen lock
- Inactive
Protocol v8
One-way broadcast without acknowledgements. Coherent OFDM at 48 kHz: 320 carriers from 0.94 to 8.4 kHz (every 8th a pilot), 42.7 ms symbols with a 10.7 ms echo guard, QPSK or 16-QAM. 5G NR LDPC codes with soft decoding; each packet carries 180 bytes and a CRC-16.
Files use a fountain code: any K packets rebuild K, in any order, so Send again or Repeat ×3 add new packets instead of copies. Short messages are one codeword; every repeat adds new parity. A sync burst (chirp, two training symbols, descriptor) starts every ~3.5 s, so receivers can join late.
| Mode | Modulation | Code rate | Packet | Speed | Needs |
|---|