Actually, a pretty casual Google search will turn up homebrew designs using a can of high-concentration salt water as an inexpensive (though not very stable) dummy load.
And that's pretty much what the salt water "antenna" would be. 73, Dave AB7E On 10/17/2010 11:30 AM, Kok Chen wrote: > On 10/17/2010 1:40 AM, Jan Erik Holm wrote: > >> This will go nicely with my K3 >> http://www.youtube.com/watch?v=9tIZUhu21sQ > Seawater has electrical conductivity of seven *orders* of magnitude > lower than copper! > > As a quick and dirty check, I created a simple 10m ground plane > antenna in NEC-4. Four counterpoises and a vertical radiating element > that is bottom fed, all of equal lengths, with the counterpoises and > the feedpoint 1m above seawater (natch!) ground. All elements 0.5" in > diameter. > > With perfectly conducting elements, the feedpoint impedance is just > about 35 ohms, with a gain of 4.7 dBi. > > When I changed the conductivity of the vertical element to 5 mhos/ > meter, while keeping the counterpoises as perfectly conducting, the > computed gain dropped to -8.2 dBi and the feedpoint impedance is > capacitive at 320 -i*250 ohms. > > I.e., something like 13 dB loss compared to using copper elements. > > BTW, I could not achieve resonance by extending the length of the > radiating element -- I guess you will need a KAT500 in addition to > that KPA500 which you use to make up for the missing 13 dB. > > This could make a good water heater. All that power has to go > *somewhere* :-). > > 73 > Chen, W7AY > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
