Hi Jacek and group   That is a very good site and the sound clips help identify stations like the Alpha nav aids. That is a really dedicated guy, I liked the auto signals I never thought they would radiate so well. I have had a similar experience to his with very low power at a range of about 1/2 to 1 km range at 7.8kc/s but at 1.8kc/s it shows there is promise on these VLF frequences.   Thanks for the URL Jacek. That site should be an inspiration to all of us experimental ops! 73 es GL petefmt --- On Sat, 13/3/10, Jacek Lipkowski <[email protected]> wrote: From: Jacek Lipkowski <[email protected]> Subject: Re: LF: Re: Induction DX? To: [email protected] Date: Saturday, 13 March, 2010, 9:14 On Thu, 11 Mar 2010, James Moritz wrote: > It is interesting to try to work out what might be possible by induction... [...] have a look at http://www.home.pon.net/785/equipment/transmitting/VLF_transmit_2.htm this experiment used two triangular loops of 15m high and 90m circumfrence in a natural area (without conductors etc). the author was able to copy a 0.5W cw signal at the distance of 3.3km! this is much more, than what is expected from free-space calculations mentioned in this thread. this is probably the effect of the ground (currents induced in the ground excite some much bigger ground loops that make up a "secondary" antenna of bigger size). another explamantion would be that the field induced at the transmitter site got into the 2m receiver that the author was using, but i hope that is not the case :) VY 73 Jacek / SQ5BPF