I’ve had a plan to build a 1/4 Wave Ground Plane antenna based on this calculator and the data available on that site for some time. I’m doing the 2m band first (144MHz) - I’ve got piece of 4mm brass diameter pipe for my driven element, and 6mm aluminium pipe for my radials. The radials are to be angled at 45° from each other, at 45° below normal. Click the link for what that looks like! …