OK, this is really annoying me.
I have an old bedside radio/alarm clock that's been fine for a couple of decades, and which still works perfectly well at night. Its crude FM antenna is a simple strand of PVC-insulated wire dangling from the back of it, with a plastic lump on the end about 1cm long and 4mm diameter which might or might not contain any components moulded in. Recently in the mornings (only), the audio has been seriously compromised by crackly interference.
It seems to make no difference how I arrange the wire antenna, but I get perfect reception whenever I hold the lump on the end of it, and back to crackles when I let go.
Any suggestions as to what's going on, and/or what I might clip on the end of that piece of wire to approximate an adult human being and suppress the interference?