); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY On Sunday 05 August 2007 12:13, Poul-Henning Kamp wrote:
> >We found the best "waveguide" experience was in > >the range of 300 to 420 MHz, but the distance is very limited, > >hundreds of feet at most. The main problem at different frequencies > >is the material becomes absorptive at lower frequencies, > >or reflective at higher frequencies causing to much mutilpath > >distortion. > > Most mines are in coal or metalrich rock, wouldn't that make > your experience more pessimistic than the tunnels at CERN which, > as far as I remember, is in pretty 'worthless' rock ? To get to the Coal Face there are miles of tunnels that have neither coal nor metallic bearing Rock. Radio transmissions there don't do much better than near the Coal/Metallic Rock. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.