>From sferics to subs, very low frequency (vlf) and extremely low frequency (elf!) seem to interest TRP. http://pub2.bravenet.com/freelink/show.php?usernum=153801959&cpv=1 For those of you who didn't pay attention in Physics 101, the lower the frequency, the longer the wavelength and the less directional a signal is. Keep cool, caring is optional. Henry Mus