Hello Chris
Thanks for sharing the information. I am also using this version of Endfed for 7,10 and 14 MHz with a 1:64 transformer using a 4C65 core material.
What does your transformer look like? Because of the relatively low permability of the core I use compared to an Amidon 43 the 4C65 needs more windings. So the performance of my transformer is only usable up to 14 MHz with low SWR. I cannot operate it on 21 or 28 MHz. The nice side is, the 4C65 is less lossy within the range defined above.
I hope to hear you again soon from a summit in your area. It is the perfect distance from here to DM/NS … for a contact on 40 m.
73
Peter