excellent

excellent

excellent

Low frequency rejection: The receiver box contains a filter with a broad -30dB notch around 48kHz as shown on a NanoVNA2 displaying 10-250 kHz. The resonance phase shift is clearly shown as the red curve. This antenna should be able to cover from 10 kHz and up thereby be able to listen uboat signals. Unfortunately that is not the case. Even low freq time signals are affected

Low frequency rejection: The receiver box contains a filter with a broad -30dB notch around 48kHz as shown on a NanoVNA2 displaying 10-250 kHz. The resonance phase shift is clearly shown as the red curve. This antenna should be able to cover from 10 kHz and up thereby be able to listen uboat signals. Unfortunately that is not the case. Even low freq time signals are affected

Low frequency rejection: The receiver box contains a filter with a broad -30dB notch around 48kHz as shown on a NanoVNA2 displaying 10-250 kHz. The resonance phase shift is clearly shown as the red curve. This antenna should be able to cover from 10 kHz and up thereby be able to listen uboat signals. Unfortunately that is not the case. Even low freq time signals are affected