NAV / COM Antenna Installation

One of the neat aspects of the composite aircraft construction method is the ability to embed your communicatioin and navigation antenna within the structure of the aircraft without degradation of the signal.  It takes the antenna out of the airstream thus reducing drag and improving the look of the finished aircraft.  The obvious challenge for the builder is finding or constructing the proper antenna, finding a place to properly mount the antenna and compensate for the normal use of the airframe structure for the ground plane.

Vertical Stabilizer - Dave Tate fabricated his communication antenna using Jim Weir's instructions and has it very neatly mounted and ready to close.

After the Horizontal Stabilizer is mounted ,the right side of the Vertical Stabilizer is mounted and bonded to the Vertical Spar and the Horizontal Stabilizer.  Prior to installation of the rib the Communication Antenna should be installed.  The above photo shows the full spread of the communications antenna.  The one used is from Bob Archer and was glassed into place with single ply bids.  As can be seen from the above photo, it just barely fits.

I tried several different mounting arrangements but all had some conflict.  The black marks on the photo above show the only alternate mounting which would work as well.  I picked the above arrangement since I was concerned that the electrical bonding cable which will run up the rear stabilizer spar would interfere with the signal.

VOR Antenna - Bill Schertz

Here you can see my VOR antenna (copper foil tape) and the coax leading to it, and the masked off and coated fuel tank area on the bottom skin. I used Jeffco 9700 to coat the fuel tank. You can also see the sanded bond line areas for the ribs and spars.