Soon after I posted I found the signal had drifted 100Hz lf and become weaker. I can no longer hear it now though there was something there yesterday. So it may in fact be local to me. 73 Dave G3YMC
Hi Alan, Since your reply I have tried various types of antenna to receive the UNID signal, as the antennas (or lengths of wire) get progressively poorer for 500 kHz the signal gets weaker until it i