Grundig Satellit 800 receiver has clocked swish, swish, swish, swish noise bursts at about 2 Hz frequency. Noise is combo of 60 Hz buzz plus white noise and affects only AM & SW when signal strength is below S9. FM unaffected. Suspect receiver-based noise as problem not evident on Grundig FR-200 operating next to 800
Audio Players & Recorders - Grundig - Satellit 800 AM/FM/SW Radio
Answers & Comments
It's lowest operating frequency should be 100 kHz, unless it has been altered. What you would hear below 100 kHz is a mystery.