Thanks for posting up that picture of the diamond adapter. I have been using the style shown in your first picture. The j-poles we made were attached with pre-installed bnc connectors to double shielded coax. I'll try and find the Diamond style.
1996 LX 450 OME heavy front/med rears, factory e-lockers, 285/75-16 Discoverer STT, home made t-case skid plate, ARB front bumper, XD9000i, Redline sliders, HID off road lights, Kenwood TM-D710
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." -- Benjamin Franklin