EFHW Transformers

[EA2BD]

Hello,

lots of useful info on the reflector if you make a search.
Just to provide a short way, just check here first, and read on in the post:

A SOTA Centric End Fed Half Wave Antenna (Part 1)

Ok Stephan, my project to improve the EFHW couplers used so far (in the slim design) lasted from spring 2018 to autumn 2019, that was a little longer than expected (…). For this purpose, after a prior evaluation using the toroidal core calculator from Owen Duffy, prototype couplers 1:49, 1:64, 1:69, 1:81 were built, measured on the workbench on purely resistive loads and back-to-back and finally tested on real EFHW antennas for 80-10 m. The following ferrite cores were considered: Amidon 2x …

Take your time to read deeply and avoid mistakes like loose coil winding, separated turns, etc

73