Guy, After reviewing specs from several manufacturers, the “recommended” minimum bend radius for RG303 and RG400 is essentially the same at 1.0 inches.
73, Bob Nobis - N7RJN [email protected] > On Feb 6, 2016, at 23:07, Guy Olinger K2AV <[email protected]> wrote: > > RG303 is not rated for the tight bends. RG400 with its fine stranded center > conductor is rated for corner bends in aircraft wiring harnesses and will not > deform the dielectric within the bends. I would not wind any solid center > conductor coax on a toroid. > > I would only buy cut lengths of RG400 after the lengths for a project are > known. Some number of such suppliers on eBay. One currently listed at 1.98 > per foot: > http://www.ebay.com/itm/RG400-Coaxial-Cable-Mil-spec-by-the-ft-US-supplier-/251260159394?hash=item3a8045c5a2:g:WpAAAOxy43FRafUe > > <http://www.ebay.com/itm/RG400-Coaxial-Cable-Mil-spec-by-the-ft-US-supplier-/251260159394?hash=item3a8045c5a2:g:WpAAAOxy43FRafUe> > > True it ain't ham cheep. The good stuff that lasts and lasts almost never is. > Back in the early days of eBay I came by a 142' length of RG400 for $25. > That's $0.178 a foot I also came by bundles of miscellaneous 6 foot to 15 > foot jumpers with various connectors on end for similar ridiculous low prices > per foot. > > The silvered copper strands stand up to migration of dampness in a way not > possible with same size copper strands minus the silvering. I have *measured* > the dry RF resistance at 1.83 MHz of a 67 foot length of corroded #14 > stranded plain copper at 62 ohms. When new this wire had resistance at RF of > less than an ohm. I have never found the silvered copper equivalent in > anything remotely approaching that degraded state. > > RG400 wound on the proper core for the job will last a lifetime. > > 73, Guy K2AV > > On Saturday, February 6, 2016, Robert Nobis <[email protected] <>> 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. > > > > ______________________________________________________________ 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]
