Hello. I’m having trouble understanding your post as the frequencies seem to be confused. There are no bc stations on or near 15.5 kHz. If your problem is that MW stations are appearing in frequencies they shouldn’t, try pressing the ‘MW Notch’ button (small MAIN panel) and see if that cures it.
If these ‘images’ appear in places where they cause problems and the MW notch doesn’t help, try clicking up one end of the spectrum so that the LO figure changes, then retune (using the mouse wheel) and take another look. The chances are that the unwanted signal will be somewhere else.
This is a problem for all hybrid SDR’s that boast a wide spectrum display – you can’t put narrow front-end filters in without ruining the nice wide display!
BTW, the RSPdx has the ‘high dynamic range’ feature for frequencies below 2 MHz, but you may need the new 1.4 software version of SDRUno to access it. Don’t quote me on that as I’m a little way behind at the moment.