Biquad dipole or vertical antenna jig

thingiverse

You can use this jig to make a biquad or really antenna that uses ¼ wave elements.I used it to make an omnidirectional biquad antenna something like this, but could also be used for a directional antenna like this. Using the outside of the box to make the elements, mine looked good on a nanovna w/o needing any adjustments, but YMMV.For a vertical ground plane, a single face can be used to cut 5 elements to length, using one for the radiator, then 4 more for the ground plane - bend down at 45 deg.