So, now that I have a VNA, and I could see just how terribly my original version of this antenna was, I decided it was time to make a new one. I started following these directions from WD4R, aiming for resonance around 146MHz, right in the middle of the 2m band.

However, once the antenna was complete and I hooked it up for analysis, I quickly found that it was resonate much lower than that, with SWR > 2 for most of the 2m band. The graph made it easy to see which way I needed to adjust the antenna to get it more resonant, and luckily I needed to make it shorter instead of longer. Cutting the antenna shorter effectively shifts the graph to the right, towards resonance at higher frequencies.

Cutting about half an inch from the top of the antenna at a time, I repeated the analysis until it showed excellent performance across all of 2m. At either end the SWR is around 1.6, and in the middle it’s as low as 1.16. I ended up with a final measurement for total length of 50.5″. And lo, when I went back to look at the original ARRL article from 1994, it showed 50.3″ rather than the 54″ in WD4R’s diagrams.

This antenna would have been unusable in its original state. The tuning process with the NanoVNA got it dialed in in about five minutes. Now I just need to get on the air and try it out!