Spiderbeam HD 12m Fiberglass Mast Mount

After I had to take down my M0PLK Delta Loop, it was time to experiment with new antennas. In a corner of our garden, there has been a Hustler 4BTV vertical antenna for quite some time, which I have only ever used for 40m operation. Now I had the idea of replacing it with a 1/4 wave vertical antenna for the 40m band. The matching radials for this were already under the turf, so I only had to swap the Hustler for a 10m mast. I finally decided on the HD version of the 12m Spiderbeam fiberglass mast, from which I simply removed the top two elements to get the desired 10m. Unfortunately, I only had a short steel mast stub with a diameter of 42mm available for mounting the fiberglass mast. A first setup, in which I attached the mast with a tensioning belt, unfortunately did not last long.

Then I had the idea of printing a mast mount. In the end, the following design was created:

I’ve printed two of these adapters and slided them over the lower tube of the mast which has an outer diameter of 55mm. Then I used a total of four stainless steel hose clamps per adapter: two to attach the adapter to the steel mast and two more to prevent it from moving up or down. To protect the Spiderbeam mast, I’ve cut stripes from a bicycle tube and placed them under the hose clamps:

This is what the construction looks like when mounted to the steel mast.

You can download the design here.

Update 2025/02/10: This design as OpenSCAD file can be found here.