This is a 8 element collinear antenna made from LMR 400 coax. The 1st and last elements are 1/4 wave length while the others are 1/2 wave length with velocity factor. I put it inside a 3/4" PVC pipe. The results are in the images below, I am very satisfied with the results. I built this antenna to feed data to Flightaware using a Raspberry Pi and a Flightaware dongle. You can see my results in real time here.
{gallery}/Collinear_Antenna{/gallery}