Some months ago, Bent OZ1CT asked me for a X-pol LFA (two LFA Yagis, one in the vertical plane, one in the horizontal plane on the same boom). Whenever I have received such requests I have been reluctant to work on them due to the many complexities involved in not just getting the model working but getting it working correctly and as model.
There are designs from many well-known designers and commercial entities around today but none that I have seen get it right in the electromagnetic design or mechanical construction and this in part is due to the lack of understanding of off-sets (elements) and the impact certain materials will have upon this antenna and without doubt, this is the main reason many hams are not 100% happy with their X-pol arrays.
I have spent much time modeling X-pol array in EXACTLY the arrangement they will be in once built, established the issues and made every effort to avoid and reduce any distortions. The details and result fo these findings will be published within the pages of DUBUS a little later this year but for now, take a look at one of the first ever X-pol LFA Yagis at OZ1CT.