Hello,
yes, I have also performed an OSL calibration in the 150-190 MHz range. The SWR at 172 MHz is 4.5
I made the legs from copper wire with ~1mm diameter. The legs are mounted in a plastic tube. The feed element is a BNC - 4mm connector as shown in the attached picture. The antenna is mounted in vertical position and hangs from the ceiling.
by the way, the antenna works fine at 172 MHz
hobride