On a point of information, the aim with underground communications is to 
achieve a speech link over several hundred metres or more.  The best I know of 
on 87 kHz is 1.6km two-way and 2.5km one-way in Vercors limestone.

John F5VLF

On 19 Jul 2010, at 00:04CEST, Mike-WE0H wrote:

> It's better to have an antenna no matter what shape or form it is rather than 
> NOT having any antenna. We wont learn a thing if everyone would just use 
> traditional antennas and never experiment with other types of antennas. This 
> is what Amateur Radio is all about, Experimenting and trying new stuff.
> 
> If we all wanted to communicate nearly error free with zero QRM, we'd just 
> email each other and call it a day.
> 
> Real Amateur Radio is experimenting. Keep up the good work guys. It is very 
> interesting reading about your success and failures. Some people will like 
> what you do and some will think your nuts. It doesn't matter one bit who says 
> what. Have fun and enjoy what you do.
> 
> Mike-WE0H
> 
>