Matt

I suspect that the colorant in ABS is carbon black.

Make sure there is little to no carbon content, which would seriously alter antenna and system performance. BLACK anything -- including plastics -- is usually the worst, as they often have high carbon content. Think of applying black paint with carbon in it as applying very thin, black tin foil. Would you do that? Of course not. It would be both a shield and reflector, both of which are bad for the antenna (shield), the system connected to it (reflected power, VSWR, etc.), not to mention system performance.

Richard
www.craggyaero.com