Hello Walt Having just done a quick Internet search I have come up with an interesting site: www.qsl.net/sv1xv/lf.htm The site is called 'the world below 535 kilohertz' It has a load of links which I don't have time to explore at present. One mention is of the LFCA - Low Frequency Club of America - these bits of information may help you further. 73 -- David W Wood