It’s really rewarding to notice that many people all over the world have read and are reading my article on the multi/any-band HWEF. Please be aware however that this article is from 2011 and I recently (winter 2019) have published an article on the (limited!) bandwidth / working range of the HWEF 1:49 auto transformer . I’ve measured four different transformers including the Steve Wellington (N4LQ) design. Highly recommended! I’ve also written an update on the trapped 80/40/20/10 HWEF I’m using nowadays.
Then… I recently did some experiments with a vertical HWEF for 10m/15m with a FT240-52 based 2:14 transformer on 10m agl. I should be a low angle canon blowing the dx out of the water but… It didn’t. My calculations and measurements on (several!) transformer(s) and (several!) L/C match(es) looked promising but in practice, the antenna miserably failed the tests. I’m still figuring out what went wrong, can’t get my fingers behind it yet. So there you go, not all my experiments have good results, I guess that’s the idea of an experiment. The challenge is of course to find out what is wrong so… I’m not giving up on this vertical yet but after three weekends of work, I took my loss and put the old Hy-Gain 12AVQ vertical back on the chimney today HI. I will keep testing the 10/15m concept with some sloping wire (instead of a vertical aluminium tubing pole), see if I can get it to work.
Happy Holidays for you and your family and I wish you a radio active 2020!
73 de PA3HHO (Pleun)