Thought I would take a look at what was going on in the VLF spectrum this morning here in TN. I first looked at 0-48 kHz, but immediately noticed that I could only see two signals above 27kHz, and no manmade signals (except power line harmonics) below 16kHz, so I took a screen capture of the spectrum from 16-27kHz, where most of the activity was concentrated, so that the signals are spread out more on the screen capture for better identification.

 

 

 

From left to right we first see (and I am going only by the station ID markings on the Spectrum Lab screen) HWU on 18.3kHz in Rosnay, France. Next we see NWC on 19.8kHz in Australia. I'm sure they will be happy to know that their million watt signal is coming in nicely. Then it seems I was fortunate enough to catch RJH6X transmitting what appears to just be a carrier on 20.5kHz. Spectrum Lab IDs this as a Russian station, sporadic. The signal is now gone as I type this. Going a bit higher in frequency, we see FTA on 20.9kHz which SL IDs as coming out of France. Next is NPM on 21.4kHz transmitting out of Hawaii. Next up is GQD on 22.1kHz, located in Anthorn, UK. I imagine you folks in RSGB receive that one a bit better than I do. Then we have DH038 on 23.4kHz which is located in Germany. The next three signals you see are "local" (meaning continental U.S.) stations, NAA, NLK, and NML on 24, 24.8, and 25.2kHz.

 

This was using an active e-probe through a 50kHz LPF into a computer sound card. Timestamp is in UTC.

 

I think it would be interesting to compare this to a screenshot of the same frequency range taken from one of you gentlemen across the pond.

 

 

Best 73,

Doug KB4OER