NIL HEARDRECEPTION LOG

VLF submarine band 23.3-25.7 kHz (DHO38, NAA, Russia, Turkey chord)

tier A · data

23 kHz USB · 2026-10-05 19:10:26Z · 10:00 · received at Assen | Netherlands

Spectrogram of VLF submarine band 23.3-25.7 kHz (DHO38, NAA, Russia, Turkey chord), 23 kHz USB, 2026-10-05 19:10:26Z, 10:00: data 50% · morse 27% · carrier 20% · mixed 3% · tone 401 Hz · keying 2.25 Hz depth 0.71
spectrogram 0–6.0 kHz · analysis blocks: morse data carrier mixed
loop [ ] · speed in the player bar · deep link #t=seconds ⤓ FLAC 10.2 MB ⤓ Opus 2503 kB { }
What was heard
data 50% · morse 27% · carrier 20% · mixed 3% · tone 401 Hz · keying 2.25 Hz depth 0.71 — dominant tone 401 Hz, keyed at 2.25 Hz (depth 0.71). Machine description of the sound by the rig's classifier; it sorts, it does not certify a station.
Receiver
KiwiSDR, Assen | Netherlands (JO32fx) · Active Loop antenna PAHGOR (serial nr: 001) built by ► PA0EBC ◀ 👍 · reported SNR 43 dB — thanks to the operator. Receivers
Provenance
sha256 44f9091a5fa8e6204a323c649ac503c568c8e1f322a487996698dd068031539f
source 10:00 WAV, 11999 Hz mono
kiwirecorder.py (jks-prv/kiwiclient v1.11) · rig item 2026-10-05T1910Z-23-vlf-23000
Heard in the record
— linked once the record exists.
Licence
CC BY 4.0 — credit NIL HEARD / Reception Log. The recording is ours; the transmission is somebody else's. Descriptions describe sound, never content — why.
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