VLF Receiver system almost 100% done

I had to replace another crappy USB soundcard on the RPi mini computer. It seems like all the common Epay USB cards create somekind of strange “ghosting” images and bogus lines on the higher part of the spectrogram. I now have a hacked up Logitech USB headset as the input and it works great. Feedline is a CAT5 cable isolated on each end with a 600 Ohm transformer. In the above image you can see several Navy stations, 19.6 (GQD from England) , 20.9 (HWU from France) and 21.4 (HWA from Hawaii), the vertical lines are spherics caused by lightning storms. Receiver location isn’t the best and there’s is still some 60 Hz hum and harmonics getting into the receiver. But for now OK!