I have made no measurements, but experience gained from zip cord bought from Wal-Mart, left me with the conclusion that it indeed was pretty poor. Thanks for the confirmation of why I had no QSOs from Idaho!
73 Stephen G4SJP On 16 May 2011 17:51, Jack Smith <[email protected]> wrote: > 10 years ago, I measured the loss of zip cord, with the results below. > The measured results are based on a 17 ft length of zip cord. > > Frequency Measured Loss (dB) Loss (dB)/100 ft > 5 0.4 2.3 > 10 0.6 3.5 > 15 0.8 4.6 > 20 0.95 5.5 > 25 1.2 6.9 > 30 1.4 8.1 > > > For comparison, RG-58 is spec'd at 1.4 dB/100 ft at 10 MHz and RG-178 at > 3.3 dB/100 ft. So, zip cord is about as good (or bad) as RG-174 at 10 MHz. > > I've significantly improved my measurement ability since then and should > revisit the subject. > > Jack K8ZOA > > > > On 5/16/2011 12:02 PM, Dale Putnam wrote: >> Zip cord, at 50 - 72 ohm or so impedance, is a whole lot closer to the >> center fed impedance of a "close to the ground" dipole. >> Makes a fair amount of sense, to use it for feedline, clear down to the rig, >> when the rig has a balanced output.. or to the balanced to unbalanced, 1 to >> 1 ratio apparatus. And with a stranded, larger than RG-58 or RG-59 coax >> center, it won't have any additional I-R loss than that coax, and our HF >> freq. And of course, making the distinction that we are talking about a >> single band dipole... not a multiband, center fed with what ever the tx is >> dialed to balanced antenna. >> >> --... ...-- Dale - WC7S in Wy >> >> >> ______________________________________________________________ >> 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 > ______________________________________________________________ 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
