I built one once long ago from the ARRL antenna book. It worked fairly well. Used copper screen for the skirt and disk reinforced with 12g wire. Soldering the seam used half a roll of solder and 2 tips on my old Weller gun. But it did work, I had it in an attic but I noticed weatherproffing it could have been a problem for outdoor use. I used it to hit local repeaters on 2m and for scanner.