I make my own wingtip VOR/LOC/ILS antennas. As shown in the photo the antenna is mounted on a short piece of thin 3/4?x3/4? angle that is attached to the end rib with a couple of screws. The advantages:
- Wingtip just fits over the antenna so the antenna stays on the plane when the tip is off. The outboard edge of the antenna fits into the wingtip outboard seam and does not move.
- You will note the Archer antenna does not extend as far out into the wingtip as there is room. Making my own antenna I can change the dimensions to use all the space outboard of the last wing rib - so the critical part of the antenna (the part that extends out) is optimized.
- Note that I mount the antenna a little aft. This gains distance from the NAV/Strobe to minimize RFI. I would never run nav/strobe/landing light wires along the antenna itself.
- The antenna is made of aluminum out of the scrap box - so trivial cost.
Disadvantage: You need to have an antenna analyzer to tune it (but then I would also consider this a prudent step for the Archer antenna, as well as the comm antennas).
Photo is an RV-14A install. Note the antenna is several inches too long. Photo was taken before tuning. The black tape is just to keep it in about the right configuration, again for tuning.