On Thursday, May 10, 2018 at 12:46:15 PM UTC-4, wrote:
On Thursday, May 10, 2018 at 11:08:48 AM UTC-4, Matt Herron Jr. wrote:
On Thursday, May 10, 2018 at 7:38:17 AM UTC-7, wrote:
On Thursday, May 10, 2018 at 10:07:15 AM UTC-4, Matt Herron Jr. wrote:
Flarm antennas are a real pain for ships with carbon hulls. Coverage is always poor, especially below. Is there a way to make a perfectly flat and thin antenna that could be taped to the outside of the hull and fed through a small (1/8"?) hole? I am thinking 2 thin wire strands, or foil strips, fed through from the inside, then taped in place with wing tape. I would put one on either side of the nose for good coverage. The wires could even be longer (some wavelength ratio) for better gain. The tiny hole could easily be filled later if the install was reversed.

Any RF engineers out there care to take a shot at this?

The power radiation pattern would not be favorable.
UH

Why is that?

Because the antenna would be too close, and parallel, to the conductive fuselage. A "whip" that is perpendicular to the fuselage (and 1/4 wavelength long - that's about 6 inches) would be much better, but of course add more drag, and be vulnerable to being damaged by tall grass etc. An antenna in an enclosed, streamlined bubble of a compromise depth and made of a non-conductive material (e.g., fiberglass) is probably the best solution.

- oops, (a bit over) 6 inches is half wavelength. 3 inches for quarter wavelength (which requires a ground plane). 300/MHz=wavelength in meters