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
