Bob, Yes, it is a bit expensive: $2.91 per foot from “The Wireman” plus shipping. (For lengths under 100 feet.)
73, Bob Nobis - N7RJN [email protected] > On Feb 6, 2016, at 18:21, Bob McGraw K4TAX <[email protected]> wrote: > > Yep, good stuff. Be sure of your budget before buying a roll. It is a bit > pricey. Handles legal limit HF power with a reasonable SWR. > > 73 > Bob, K4TAX > > > > On 2/6/2016 7:10 PM, Robert Nobis wrote: >> I have used RG303/U for chokes. A bit smaller diameter than RG400 (0.170 >> versus 0.195 inches). RG303/U has a solid copper center conductor that is >> silver plated. The shield for RG303 is also silver plated copper. The >> jacket is Class 9 Teflon. Also the dielectric material is teflon. >> >> 73, >> >> >> Bob Nobis - N7RJN >> [email protected] >> >> >>> On Feb 6, 2016, at 17:49, Guy Olinger K2AV <[email protected]> wrote: >>> >>> If one wants a small 50 ohm coax that will take QRO with a very large >>> margin and was *designed* for bending and use in aircraft wiring harnesses >>> then use RG400 to wind around your core. RG400 uses a fine stranded >>> silvered copper center conductor that is more flexible than its Teflon >>> dielectric. It has a double shield made from silvered copper strands. >>> >>> That's silvered strands whose silver sulphide patina or tarnish is >>> conductive as opposed to the green copper sulphate that separates copper >>> strands that have been water soaked. >>> >>> Wind the coil form with RG59 to get the length and buy just what RG400 you >>> need. You can buy brand new RG400 by the foot. With the Teflon dielectric >>> you can solder the RG400 without worrying about melting it. >>> >>> Do it with the good stuff to start with and put it in your will. >>> >>> 73, Guy K2AV >>> >>> On Saturday, February 6, 2016, Ron D'Eau Claire <[email protected]> wrote: >>> >>>> Bob makes an excellent point. I've seen cases where even "solid" dielectric >>>> did that over time because, after all, it is not really solid. The >>>> dielectric is plastic so the coax can be bent. >>>> >>>> All coax has a minimum bending radius specification. Specific data is >>>> available on line but, in general, RG58 size cable usually has a minimum >>>> radius of 1 to 1.5 inches (2.5 to 3.8 cm) and RG8 size cable has a minimum >>>> radius of at least 2 inches (5 cm). Note that is radius. If you curl the >>>> cable into a circle the minimum diameter of that circle should be at least >>>> twice that or 3 to 4 inches (7.5 to 10 cm). >>>> >>>> It's not something I've found especially critical in HF applications at >>>> least around my shack, but tighter bends, which may not actually cause a >>>> short (yet), alter the impedance as the center conductor migrates toward >>>> one >>>> side so it is no longer equally spaced within the shield. This can be a >>>> serious issue in microwave and even UHF installations. >>>> >>>> 73, Ron AC7AC >>>> >>>> >>>> >>>> -----Original Message----- >>>> I would have concern that long term usage of RG-8X, being foam core >>>> dielectric material and bent in a tight radius, may allow the center >>>> conductor to migrate to the inside radius of the bend. The Minimum Bend >>>> Radius for RG-8X is 2.50". Thus the tight bend will allow the center >>>> conductor to short to the shield. A solid core dielectric coax such as >>>> RG-303 is much preferred. >>>> >>>> 73 >>>> Bob, K4TAX >>>> >>>> >>>> ______________________________________________________________ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:[email protected] <javascript:;> >>>> >>>> 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] <javascript:;> >>>> >>> >>> -- >>> Sent via Gmail Mobile on my iPhone >>> ______________________________________________________________ >>> 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] >>> >> ______________________________________________________________ >> 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] >> > > > ______________________________________________________________ > 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] > ______________________________________________________________ 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]
