Just finished mounting the new Radome to my roof rack. Total cost not including tools: under $20.
It started out as the upper half of a smaller diameter, out-of-date SCBA composite tank that I was given for free since it was just going to be thrown out anyways. I just chopped it off at 9" tall with a big chop-saw and sanded the dome end nice and round/smooth.
Some paint and red tape added. I cut out the mounting plate from some scrap plywood.
I have no access to a welder, so for the support post, I went to Home Depot and bought two 3/4" mounting flanges, a 12" long black steel pipe already threaded 3/4" on the ends and eight 1/4" carriage bolts/nuts. I cleaned the flanges and pipe, painted them and the plywood platform red, then mounted it all together onto the left rear corner of my roof rack.
According to the blueprints I found digging around on here, the dimensions called for the dome to be 6" in diameter and 9" tall. Mine ended up being 6-1/4" in diameter and 9" tall. Considering I was unable to add the angled support braces to the post, I think the measurements are close enough to look good. Especially since the car is not an older professional car, but a modern conversion(GMC Terrain). Now to dress it up with an ESD warning label and a small antenna or two on the rear corners of the mounting plate.