Helically wound multiband vertical antenna-portable in Poland
Walt (K4OGO) came up with this helically wound vertical antenna while he operated as SP/K4OGO in Poland.
Other than a narrow bandwidth, this antenna provided multiband capability at a modest cost. The key to this antenna design was the 9:1 balun used in the feed line.
If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=pHa7A6f3LMI
Here are some comments from Walt (K4OGO):