As one who has been exploring caves for the last 40+ years, my principle interest in the 630M band is its ability to communicate thru solid rock. There is a long history of cave radios operating on medium frequencies under part 15, most of which use antennas consisting of a coil of wire. (One of the rules of thumb for cave radios is that the antenna and the battery should weigh about the same.)
Cave radios used for communication are quite different from those used to locate the surface point directly over an under-ground point, and estimate its depth. If you are interested in cave radios, most of the work in the US has been documented in Speleonics, published by the Communication and Electronics Section of the National Speleological Society. All issues are available for free download from <http://www.caves.org/section/commelect/drupal/speleonics>. The most recent issue has an index of all issues and is available from <http://www.caves.org/section/commelect/splncs/splncs28.pdf>. There is also an active British group, the Cave Radio and Electronics Group <http://bcra.org.uk/creg/>. They accept Paypal for their publications. Cheers - Bill, AE6JV On 7/10/12 at 1:13, kl...@acsalaska.net (Edward R. Cole) wrote: >I think the KX3 still has promise of being a good 630m radio >(with a little help from its friends). 630m will likely be >slow to start (just like the 60m band), but in time there will >be a decent population there. Right now it is still an >experimental band. ----------------------------------------------------------------------- Bill Frantz | gets() remains as a monument | Periwinkle (408)356-8506 | to C's continuing support of | 16345 Englewood Ave www.pwpconsult.com | buffer overruns. | Los Gatos, CA 95032 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
