HF Loading Coil Sleeve

***This is a work in progress***

This is the second version of an HF loading coil I built. This version is designed to sleeve over a 1.5" piece of PVC pipe for the greatest support. My first design was entirely 3D printed, and obviously, the layers were going to be a failure point.

The coil is wrapped with 18 gauge galvanized steel wire from Lowes. I attached the steel wire to the 3/8" hardware using crimp ring terminals, as you cannot solder to steel. I decided to include an SO-239 on mine as I sometimes operate POTA from the car and sometimes will use the antenna on a tripod in the grass.

Tests with a 102" whip on my truck proved to be successful, according to my NanoVNA anyways. Bandwidth was a little on the narrow side, but nothing that I can't deal with. I was in a parking garage on the top floor, so I still need to test this near the ground and with a radial system. I was able to tune every band from 40m on up. I still had some coil left when I was tuning the 40m band,