Lew, Look up RG9 I think it 52 OHM coax that has two shields.
73 Ken K5DNL ---------------------------------------------------------------------- --- On Wed, 4/13/11, Lew Phelps K6LMP <k6...@me.com> wrote: > From: Lew Phelps K6LMP <k6...@me.com> > Subject: [Elecraft] OT trying to identify "mystery" coax cable > To: "Elecraft Reflector" <elecraft@mailman.qth.net> > Date: Wednesday, April 13, 2011, 11:58 AM > I was browsing through the local > Salvation Army Thrift Store (where I sometimes go looking > for low-priced antique treasures), and stumbled across a > 50-foot length of RG-8-type coax cable. At the asking price > of $6.00, I couldn't pass it up. > > It has Amphenol male "UHF" connectors. And absolutely NO > markings on the cable itself indicating manufacturer or > type. The OD of the cable varies from point to point, but > averages about .405 inch, which puts it in the RG-8b family. > It is quite flexible, and clearly stranded center conductor, > not solid. Capacitance of the 50 foot cable > was measured 1155 pF, or 23.1 pF per foot, which eliminates > some RG-8 flavors that have 30 pF per foot. The only > distinguishing feature of the cable is that there appears to > be a wire would spiral-wise (1/2 turn per inch) outside the > standard foil shield and under the exterior rubber > sheath. I've never need that construction before on > any RG-8 cable. (I haven't cut it open to verify the > construction, because I don't want to have to de-solder and > reconnect the Amphenol connector.) > > I attached the cable to my dummy load and to the HF output > of my K3. Keying the transmitter at 12 watts produces > an SWR of 1.05:1 (external SWR meter) on all bands up to 6 > meters, and continuity checks confirm that the cable has > neither short circuit between shield and cable nor open > circuit. In other words, it appears fit for duty. > > Two questions; > 1. Anything else I can or should do to check the cable and > make sure it's OK to use? (Unfortunately, I do not own > or have access to an antenna analyzer.) > 2. Based on the "spiral winding" between the shield > and outer coverk does anyone have an idea what specific > cable this might be? > > Thanks, and 73 > > Lew K6LMP > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
