The antenna is mounted about 15 feet up the first tree, with a ground wire running all the way down to a ground rod. Its far end is attached high in an adjacent 150-foot tree, which leaves the antenna in a near-vertical configuration.
After experimenting with several antenna types, I found the end-fed half-wave inefficient and not especially practical for my use. That may not be true for everyone. I am in the Tennessee Valley—quite literally, with the river nearby and mountains around me. Low takeoff angles do not do me many favors, so I generally need higher angles or antennas that run more nearly parallel to the horizon.
As shown in the photo, the ground wire runs down below the tree to a ground rod, which is bonded to the entire grounding system of my house and radio system. This forms the counterpoise for the antenna system. The photo on the right shows the antenna’s choke. This is how I installed mine.
Where MyAntenna shines—and where it does not
I am fortunate to have a tree more than 150 feet tall next to this one, so MyAntenna ends up behaving much like a vertical antenna. I primarily use it on the 80-meter voice band, sometimes called 75 meters, and occasionally on 40 meters. On the other bands, the performance has been lackluster at my station; I seem to lose a fair amount of energy as heat. The matching unit is a 56:1 UNUN.
Trying an off-center-fed half-wave
I have also used off-center-fed end-fed half-wave antennas. I have found them to work much better, but they are much more difficult to tune properly. I almost always need an external tuner on several bands. Even with a tuner, though, they have performed better than MyAntenna on the higher frequencies.
For a 40-through-6-meter antenna, I typically place the choke about 12 feet down the coax. That is the measured choke point I used for the antenna shown here.
An alternate ground-return arrangement
This off-center-fed end-fed half-wave is a little different because it can use a ground wire instead of the coax exterior as its return path. On the right-hand side, the ground wire can be the same approximate length as the coax section—about 12 feet for this setup. I put the choke immediately below it when using that ground section as a counterpoise rather than the coax. Using both return paths can make the antenna harder to tune and operate consistently.
The photos are not a beauty contest—I was moving the antennas at the time—but they show the idea. When I had trouble using one of Palomar’s antennas in a mobile environment, I could not get the coax into the proper position for tuning. I added a ring with a crimped wire at the correct length to the antenna ground section. The wire is not attached in every photo because I did not take those pictures at the time, but the ring shows where it normally went.
What I learned
This arrangement worked for me when I was having tuning problems. I do not know whether it is the ideal engineering solution, so anyone who copies it should take responsibility for their own installation and consult an antenna engineer when needed.
The first antenna is generally easier to get close to tune. The second takes more work, but when it is tuned properly—or used with an antenna tuner—it has performed better for my needs.