Hello Fredrik / Ola,
Thank-you so much for your clear explanation.
This suggests to abuse of your kindness for two related question more, if possible.
1) i have seen agricolture activities performed under the antenna : which is the depth of the buried ground network ?
2) the method that you have described for linking coils to ground network at tower 2-5 is really interesting. As the reason of this is not clear to me, do you have perhaps some simulation model (4nec, EZNEC, Feko…) of the antenna in order to play a bit around ?
In any case congratulation for the effort. I Will listen Grimeton in Christmas !!