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.htm The 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/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 Message delivered to [email protected]
