VLF/LF (Very Low Frequency/Low Frequency)
VLF: 3 KHZ - 30 KHZ
LF: 30 KHZ - 300 KHZ
The 2200m band (135.7 - 137.8 KHZ) is part of the LF (LowFrequency/Langwelle).
Antenna is a MiniWhip.
VLF-Converter (DD3ZE) converting 10 - 600 KHZ up to 10 MHZ.
Receiver is my SDR.
Just testing also a Low-Pass-Filter (<600 KHZ).
Recorded these unknown signals with Argo QRSS Viewer on 135.7KHZ
Recorded DCF77 on 76,2 KHZ USB with HDSDR/Argo
Recorded LORAN-C (Long Range Navigation) around 100 KHZ with HDSDR
Recorded ESR-Teleswitches
129.1 KHZ: Mainflingen (Germany)
135.6 KHZ: Lakihegy (Hungary)
139.0 KHZ: Burg (Germany)
Recorded WSPR (136.0 KHZ)
No signals:
Recorded WSJT-X (136.13)
No signals!
Recorded Opera (136.0 KHZ)
Recorded Argo QRSS (137.7)
No signals!