{
  "schema": 1,
  "protocol": "VARA HF",
  "bandwidth_hz": 500,
  "level": 7,
  "frame": "OFDM data frame carrying Winlink FQ close request",
  "caller": "W9SSJ",
  "called": "K5DAT-13",
  "direction": "tx",
  "source_kind": "local rig transmit monitor",
  "audio": "audio/vara-ofdm-k5dat-0930.flac",
  "sample_rate": 48000,
  "channels": 1,
  "sample_width_bytes": 2,
  "samples": 211200,
  "duration_s": 4.4,
  "original_start_sample": 4632000,
  "original_end_sample": 4843200,
  "original_start_s": 96.5,
  "original_end_s": 100.9,
  "packet_sha256": "9fcf2548dbac0ef8af07ea2412eafc0885c910101ea3b437dec924952f8574b6",
  "frame_bytes": 197,
  "point_count": 1584,
  "carrier_count": 11,
  "crc": "CRC-16/GENIBUS, expected 0x4875",
  "content_review": "Session-closing control data, zero padding and trailer; no mail body or authentication material.",
  "scope": "Supplemental recorded frame, not another curated QSO. BW500 L7 is narrowband OFDM, not the maximum wideband VARA level.",
  "normalization": "receiver decision-input gain",
  "audio_file_sha256": "9e962f2e070ec0f7d957b020c0b637a0afacac04c89b1586d31ed5c96a98b17b",
  "original_recording_file_sha256": "8f7c239efce00d3ac7274de397561acc02455b088709c2d4ed9afa901c88d7f1",
  "pcm_s16le_sha256": "aa22e6b58187185a59d781d50d49aeb0bc7388ebf9cc69b759b6850001e876e1",
  "session_started_utc": "2026-09-30T05:39:36Z"
}