NIL HEARDRECEPTION LOG

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

tier A · carrier

23 kHz USB · 2026-09-27 08:40:07Z · 04:08 · received at Assen | Netherlands

Spectrogram of VLF submarine band 23.3-25.7 kHz (DHO38, NAA, Russia, Turkey chord), 23 kHz USB, 2026-09-27 08:40:07Z, 04:08: carrier 54% · data 31% · morse 15% · tone 401 Hz · keying 1.32 Hz depth 0.72
spectrogram 0–6.0 kHz · analysis blocks: morse data carrier
loop [ ] · speed in the player bar · deep link #t=seconds ⤓ FLAC 4.2 MB ⤓ Opus 1027 kB { }
What was heard
carrier 54% · data 31% · morse 15% · tone 401 Hz · keying 1.32 Hz depth 0.72 — dominant tone 401 Hz, keyed at 1.32 Hz (depth 0.72). 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 32 dB — thanks to the operator. Receivers
Provenance
sha256 ac6da9dd62083d3ae8ec9b038fa707a35bd36c34a672ebdfae47b29356e228a0
source 04:08 WAV, 11999 Hz mono
kiwirecorder.py (jks-prv/kiwiclient v1.11) · rig item 2026-09-27T0840Z-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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