On 12/17/2018 6:45 AM, Don Wilhelm wrote:
However, if you are using the speaker wire as a transmission line, it has relatively high loss characteristics
Compared to what? So-called speaker wire (which is really lousy for speakers because it should be twisted pair to minimize RFI) has Zo in the range of 75-100 ohms. Unless it's wet, virtually all the loss in transmission lines below about 100 MHz is due to wire resistance, not dielectric loss. There is, of course, additional loss due to any mismatch that may be present, but that still comes down to loss in the resistance of the line. While I haven't measured any zip cord, I've measured a lot of closely spaced parallel wire transmission line made from THHN, enameled copper, and Teflon insulated #12 silver-coated copper. 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.
73, Jim K9YC ______________________________________________________________ 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]
