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

tier A · carrier

23 kHz USB · 2026-10-06 09:59:54Z · 10:00 · received at Mullingar, Westmeath, Ireland

Spectrogram of VLF submarine band 23.3-25.7 kHz (DHO38, NAA, Russia, Turkey chord), 23 kHz USB, 2026-10-06 09:59:54Z, 10:00: carrier 47% · data 43% · morse 10% · tone 404 Hz · keying 5.20 Hz depth 0.70 — spectrogram 0–6.0 kHz · analysis blocks: morse data carrier

loop [ ] · speed in the player bar · deep link #t=seconds ⤓ FLAC 10.4 MB ⤓ Opus 2478 kB { }

What was heard

carrier 47% · data 43% · morse 10% · tone 404 Hz · keying 5.20 Hz depth 0.70 — dominant tone 404 Hz, keyed at 5.2 Hz (depth 0.7). Machine description of the sound by the rig's classifier; it sorts, it does not certify a station.

Receiver

KiwiSDR, Mullingar, Westmeath, Ireland (IO63hn) · Beverage NE/SW 580m long · reported SNR 27 dB — thanks to the operator. Receivers

Provenance

sha256 abba8a7b9fb21602998920306515fdeea4b061fc0ec6f9d3ee9ae3df879193ba
source 10:00 WAV, 11999 Hz mono
kiwirecorder.py (jks-prv/kiwiclient v1.11) · rig item 2026-10-06T0959Z-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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