I built one, I have pic posted somewhere in here of it, but I'll attach it again. I did some modifications to reduce size and weight and I built only a single bay... It measures 36x24 inches and I used sch40 PVC 1/2inch with 6 guage copper ground wire (look in lowes or other stores Miscut wire section) I needed just under 10 feet to make my 2 elements.
Pic is on my deck as I was getting ready to cap the ends of the pvc, then I painted the PVC black for UV protection. I used hose clamps and a couple U-bolts to attach to my antenna mast pole.
only 1 word to describe it... perfomance! I use the same amp and I get stations ranging from channels 2-56 (note it claims it will not do lo-vhf, but it works just fine for me). I pick up stations from 50-60 miles away without much issue. I'm sure a double bay with a reflector would work great in fringe area. I left the reflector off for bi-directional reception.
edit: Found the drawing I used to get my mesurements for each leg of the element. This drawing is best printed on a plotter if you want to use it as a template, but the full build of the one in the PDF makes it heavy and expensive. If you look at the PDF, you can see how I took that drawing and made my own design.
