A derecho (pronounced dare-h-o) is a strong wind not accompanied by a thunderstorm. Apparently they occur in the Midwest regularly but none had ever been recorded in Colorado before last week. One went through the state and took out two elements on the big 203BA 20 meter beam. It also folded over one of the 43 foot antennas. Reports were the wind was 87 mph.
Things were going great when this picture was taken, except the elements seemed to sag a little more than expected. Once the tower was lowered and the new antenna was attached the sag became a real issue.
A week later a New-Old-Stock Cushcraft A3S was found on eBay, made before the company was bought by MFJ, and it was purchased quickly. Assembling the genuine Cushcraft felt like better qualtiy from the get-go. What’s more the elements don’t sag nearly as much. Expected reliability is much higher with this replacement antenna.
Up in the air now.
dB = log10(1-x) where x is the loss in per centage. A rule of thumb for 2.0 SWR is 10 per cent loss. Therefore log10(1-.1) or log10(.9) is .45 dB. Loss of output from a 2.0 SWR is .45 dB. That’s a loss that can be lived with.
In testing the antenna many, many FT8 qso’s were made easily. This is the best performing 15 meter antenna at this station. (Yay!) Ten meters is not as rosy.
Post script, 8/19/2020: A bad trap was found and repaired. One winding had shorted. Next, the A3S was modified to change the 20 meter band to 17 meters. It was then mounted on the small 30 ft. tower and works well. On the big 60 ft. tower the original Hygain 203BA was repaired and reinstalled. It works well, too, and all bands 20 through 10 now have a good yagi antenna. The A3S turned out to be more of an adventure than expected.