Deploying an Off-Center-Fed Dipole Antenna for 160–6 Meters

This is my fifth attempt at installing a Palomar Engineers off-center-fed dipole antenna covering 160 through 6 meters. Earlier installations were destroyed by bad weather or did not reach the height I wanted. This installation is the final version.

Installation

The antenna assembly is positioned approximately 65 feet above ground. The 217-foot wire leg extends from the feed point through the tree canopy, using a 5,000-watt hybrid balun. That 217-foot wire includes resonant compensators, and its far tie-off point is secured at the distant end of the run.

The off-center-fed dipole feed point installed in a tree — The feed point for the antenna installation.

Palomar Engineers 5,000-watt hybrid balun — The 5,000-watt hybrid balun used in the installation.

Resonant compensator installed on the 217-foot wire leg — A resonant compensator on the 217-foot wire leg.

One of the supporting trees is more than 100 feet tall. The wire passes over its top, but in the wide view it is either invisible or very difficult to see.

A tall support tree at the AF4OZ station — One of the tall support trees; the wire is difficult to see in the wide view.

Distant tie-off point for the antenna wire — The distant tie-off point for the 217-foot wire leg.

Running the wire

To run wire over trees this tall, I used a tennis-ball-type cannon—also called a DX launcher—along with a large amount of parachute cord. The launcher can throw a tennis ball with an attached cord more than 300 feet, making it possible to get wire over large trees.

Tennis-ball-type DX launcher used to run antenna wire over tall trees — The DX launcher used to run cord over the tall trees.

The other 53-foot antenna wire drapes over the trees and is not visible in the photographs. The installation took a little more than two days to complete, and the antenna now appears to be operating as expected.