Know your SWR

When I put up my HF antenna, I used an antenna analyzer to get the SWR readings and tune the antenna. Living in an urban center, my antenna options were limited. I put up an Alpha Delta DX-EE 40-10 meter on the roof of my home at about 25 feet. Less than ideal, but what I could do. 

My angle of radiation is high on 40 meters, but gets progressively better on 20, 15, and 10 meters. Unfortunately, with the solar minimum approaching, 15 and 10 meters aren’t very useable. Fortunately, 40 and 20 meters are. 

This morning I rechecked my SWR readings (a good thing to do roughly annually to see how your antenna is performing and/or degrading over time) and built a table with reflection co-efficients and power out (I run 100 watts or thereabout).

As you can see, I have a steep SWR path on 40 meters, but 20 looks amazing. When I hung the antenna, I tuned 40 for the lower portion for CW as much as I could.

See below (click on the image for an enlarged view in a new browser tab):

© Alan W Dye 2021