For exterior use, I choose to use the LMR-xxx-DB series which is impregnated with a moisture reduction substance.... intended for direct burial, it adds an additional measure of protection.
______________________ Clay Autery, KG5LKV MONTAC Enterprises (318) 518-1389 On 2/24/2016 11:39 AM, Edward R Cole wrote: > Just a comment on Times Microwave LMR cables: > > In outdoor application its "VERY" important to seal connectors properly. > > The aluminum tape shield oxidizes in presence of moisture with > resulting change in impedance and attenuation. I just replaced a > 45-foot run of LMR-600 which hangs off my eme tower supported by a > pilot cable. Because it is run vertically water entered the upper > connector and pooled at the bottom connector such that when I pulled > off the N connector water poured out in a stream for a couple > minutes. I finally had to replace the run as SWR would rise every > time temperature went above 32F. After removal I cut away sections of > the bottom end of the cable to reveal that about 18-inches had badly > corroded. New LMR-600 run has my 2m SWR lower (0.14) than it has been > for about three years (so this condition had been increasing over time). > > I run LMR-400, LMR-400UF, LMR-240 and LMR600 outside (along with > LDF7-50A and LDF5-50A Heliax). Heliax appears to totally isolate > moisture to outside the copper shielding if connectors are well > constructed and sealed. I use the LMR-240 for receive lines after my > preamps to run down to ground level where I connect LMR-400 to > continue to the "shack". > > LMR works just fine if you keep moisture from entering the coax. Only > runs of RG-213 are to my 600m inverted-L, 80/40m inverted-V and to my > tribander yagi. > > 73, Ed - KL7UW > http://www.kl7uw.com > "Kits made by KL7UW" > Dubus Mag business: > [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]
