It has been a long search for suitable materials and quite a few experimenting has been done to design a high ratio (~50:1) transformer for EFHW antennas capable of high power (1500W ICAS). In the same time, it was hard to cover the wide range of HF spectrum from 3-30Mhz, yet I did it again!
I am proud to announce that new transformer MEF-330-HP is almost double in size of its little brother MEF-330-1K and also has a bit less insertion loss on all frequencies between 3 and 30MHz. A new transformer will be incorporated into new/old EFHW antenna models EFHW-8010-HP and EFHW-4010-HP as well it will be sold separately for those who want to make their antennas for use out of HAM frequencies for their needs such as MARS, Marine or EMCOM activities.
Also, see this short video of testing the antenna with a new transformer at 1500W.
73 Danny Horvat, N4EXA aka E73M