NIL HEARDRECEPTION LOG

VLF submarine band 17.6-20.0 kHz (RDL, HWU, GBZ chord)

tier A · morse

17.3 kHz USB · 2026-10-02 00:11:42Z · 10:00 · received at Brettnach F57320

Spectrogram of VLF submarine band 17.6-20.0 kHz (RDL, HWU, GBZ chord), 17.3 kHz USB, 2026-10-02 00:11:42Z, 10:00: morse 77% · mixed 13% · data 10% · tone 2276 Hz · keying 0.35 Hz depth 0.73
spectrogram 0–6.0 kHz · analysis blocks: morse data mixed
loop [ ] · speed in the player bar · deep link #t=seconds ⤓ FLAC 10.5 MB ⤓ Opus 2490 kB { }
What was heard
morse 77% · mixed 13% · data 10% · tone 2276 Hz · keying 0.35 Hz depth 0.73 — dominant tone 2276 Hz, keyed at 0.35 Hz (depth 0.73). Machine description of the sound by the rig's classifier; it sorts, it does not certify a station.
Receiver
KiwiSDR, Brettnach F57320 (JN39GG) · vertical · reported SNR 42 dB — thanks to the operator. Receivers
Provenance
sha256 ac278d48dd15a9f087d8771c420152d271e2c73faa42b560b99f47ab26427820
source 10:00 WAV, 11999 Hz mono
kiwirecorder.py (jks-prv/kiwiclient v1.11) · rig item 2026-10-02T0011Z-17.3-vlf-17300
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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