Incorporating a VOR antenna keeps my options open. The antenna gets built permanently into the VS structure. I have to commit to the antenna choice now, but not the avionics. The Rami AV-520 happens to be an ideal size and has removable whiskers. If I eventually decide that I don’t want or truly need VOR/LOC/GS capability, the whiskers come off and the VS of the bird is clean.

Optimum mounting the antenna requires a little custom fabrication. A doubler plate must be positioned and the mating rib drilled for rivets. I ordered the doubler base-plate part number from TAF. The top VS rib gets modification to accommodate the whiskers and provide access to set-screws.

The fabrication process I undertook was a variation of what is described in the Empennage Construction Manual, pp. VS4. Eventually, small holes also need to be located and created in the VS skin to accommodate the whiskers and tool access to the set-screws. Careful positioning of the antenna base allowed me to minimize impacts to the VS top rib and the skin.

Rivet clearance areas need to be machined into the (hard plastic-like) antenna base. Several rivets also need to be shortened. The general process for rivet shortening is in the construction manual. There are places where space is tight and a bit of finesse helps to achieve good fit.