20 meter Vertical

Tuesday 1 October 2024
This antenna is out of service. It proved that I could put a quarter wave "vertical" at the height of my deck shade structure, but I learned that radials off the ground are really problematic. It took a lot of jiggering to get the antenna to resonance with two radials. It was possible with repetitive adjustments of the radial length vs the length of the vertical. But my conclusion is that what I wound up with was a "dipole" in an "L" shape. I made some contacts, but I believe better performance can be achieved with more radiator in the air.

Next up: a trap diopole for 40/20/15/10 meters.

Created Friday 26 July 2024

I built a quarter wave vertical for 20 meters. It is composed of three aluminum tubes: 1.5 inch, 1.25 inch and 1 inch. They were telescoped to tune the antenna. I sourced the aluminum tubing at DX Engineering. In its elevated position it has two opposing 1/4 wave radials that are approximately perpendicular to the vertical.

The antenna is in the place of the mast for the off-center fed dipole. I foolishly thought that I could continue to feed the dipole from that location, using the new vertical as a mast for the dipole. That didn't |work out. The resonance of the antenna was destroyed. Without the dipole feed on top, the vertical shows an SWR of 1.2 to 1 at the center of 20 meters. With the dipole and feedline at the top, the SWR became close to 5 to 1. So the OCF dipole is down. Given the space constraints of the back yard, I think I'll replace the dipole with an end-fed wire.

The new vertical in place prior to installation of guys and radials.

Initial performance was encouraging during the first evening test. I had a good CW QSO at 25 watts into central Ohio. The antenna has less reception background noise than the OCF dipole on 20 meters.