I am thinking of experimenting with mobile NVIS. I would like to install a long whip on my truck, with the tip secured down so that the whip forms a curve. It would be center loaded. Goal of getting reasonably close to unity gain, say, -3 dBi or better. I have seen Texas Bugcatchers and the Tarheel and other screwdriver antennas. Not what I want. I can use a longer whip because I'm tying the end down, and want something that is lighter weight and more flexible. Are there any relevant commercial products? Are there any good building blocks that can be purchased? I understand all the electrical theory, the challenge here is finding something that is strong, compact, lightweight, so it will go down the road at 75 miles per hour.