The EFHW - a monoband end-fed half wave for 10m, 20m or any other HF band
Update: Detailed construction details now available for download (PDF).
I like half wave dipoles. They are easy to make and easy to set up. They also perform very well and usually beat a compromise antenna hands down. With 10m about to come alive again as solar cycle 24 gets going what I wanted was a low-angle efficient radiator that could be put up and down in a couple of minutes.
My experience with ground plane verticals has been OK, but they are only as good as the earth beneath them. That is, they really need an extensive array of ground radials to work properly – not easy to put down when you are in a hurry.
I also like to use fibreglass fishing poles as antenna supports. These are available cheaply (I have a 7m version and a 10m version that I bought from Sandpiper at the Leicester rally). The only problem is that they don’t have lateral strength – they are good for supporting verticals, but not so good for half-wave horizontal dipoles.
What I really wanted to do was have a vertical half wave dipole, but the problem is that while the impedance at the centre of a dipole is about 50-75 Ohms, and very easy to match to coax, an end-fed half-wave has a very high impedance indeed, around 3000-4000 Ohms. If you just connect it to your coax or rig you will be disappointed.
Update: Detailed construction details also now available for download (PDF).