Very simple to make, you need to pull the rubber insert out and heat the end caps up so they can be removed. Ideally with a lathe make up a brass dome end and a brass washer fitted on a brass tube with cross drilled holes in it. Epoxy the ends on. I have made 12 or more now.
Thanks very much John, could you post a picture of an assembled unit please?
Even the lightest jet, well maybe not a foamie one with that 1/2N size turbine, will benefit from the UAT. Maybe in that foamie one, the only tank I'd run would be, just a UAT.
My friend with the A4 made a tiny UAT using a pill bottle for his Twinjet foamy which uses a Lambert turbine. He made a UAT using the 2 oz Sullivan tank for his A4. I guess he won't be needing that now [&o] - John.