Re: wire for random wire antenna using kx3
Posted by
John Oppenheimer on
Dec 17, 2018; 8:58pm
URL: http://elecraft.85.s1.nabble.com/wire-for-random-wire-antenna-using-kx3-tp7647146p7647159.html
On 12/17/18 1:58 PM, Jim Brown wrote:
> In order of loss at dB/100 ft at 10 MHz from low to high, the
> Teflon #12 is lowest at 0.94dB, then RG400 at 1.22 dB (about the same as
> RG58), then #12 THHN at 1.34 dB. #12 or #10 enameled copper had the
> greatest loss, 2.4 dB/100 ft.
Hi Jim,
Two parallel transmission line is the easiest of all to evaluate using a
RF resistance table and knowing the impedance of the line.
http://ve3efc.ca/wireohms.htmThe wire loss is dB = 10 * log10((Zo + WireR)/Zo)
Assuming Zo=100 for the #12 Teflon and THHN. R at 10 MHz = 4.24/100 =
8.48/200.
Wire dB = 10 * log10(108.48 / 100) = 0.35 dB
Using the two values above at 10 MHz, 0.94 and 1.34, the dielectric loss
is 0.59 dB and 1 dB. The dielectric loss is about two and three times
the wire loss.
John KN5L
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.htmlMessage delivered to
[hidden email]