RG 389 is an air dielectric cable. Make sure there is no moisture in it efore terminating it.Best way is to purge with dry nitrogen than terminate. Make sure terminations are air tight.This is a good cable but any moisture in it is not good news.I used LMR-600 a little more loss but abit easier to terminate and more trouble free or look at the LMR 900.hope this is helpful.  Jack WA1ZDV