2017-08-12, 06:37
@djhuft: You did some great work! 
A long time ago I did use a soundcard to check and identify different sources of noise like you did with the SDR. Worked great. It's normal to see submarine or time sync transmitters.
A long time ago I did use a soundcard to check and identify different sources of noise like you did with the SDR. Worked great. It's normal to see submarine or time sync transmitters.