Brief Description: Bottom Fuselage Antenna Mounting - Part 1
Since I was still waiting for those replacement wheel pants, I decided to try mounting the various antennas on the bottom of the fuselage. The compliment of RF receptors includes a COM antenna for RX/TX communications with the tower (a bent-whip), a Transponder antenna for Radar signalling (a small "shark fin"), and an FM Stereo antenna for the the DNX-8120 digital/analog AM/FM receiver (also a bent-whip). I had pulled the coax cables and terminated them with BNC connectors some time ago, but because the fuselage wasn't on the landing gear, I opted to hold off on the antenna installation since they are on the bottom.
For the two bent-whip antennas, I designed and fabricated a couple of stiffener/mounts from .032" 2024-T3 and added nut plates for attaching the four screws. Since the stiffener/mounts were perfectly square, I was able to align them to the front spar which gave me a perfect alignment of the antennas without having to do any measuring or anything on the underside. Very sweet.
The Transponder shark fin antenna came with a stiffener/mount already, and I simply used the seam in the bottom of the fuselage to align it.
I couldn't be more pleased with the installation of all three antennas. They look good and function well too.
