Todd (N7TWL) did the monthly presentation at the General Membership Meeting on 3 March, 2025. This was an updated version of an earlier presentation he did on 10 June 2023. This presentation was the very first we attempted to capture on video and was posted to our brand new YouTube channel. It is also embedded here for your viewing pleasure.

This is the PDF file referenced.

This is the PowerPoint file presented.

References:

https://www.qsl.net/dk7zb/Baluns/Endfed.htm

https://www.electronics-notes.com/articles/antennas-propagation/end-fed-wire-antenna/multiband-end-fed-half-wave-efhw-antenna.php

https://batteryeliminatorstore.com/blogs/ocf-masters-articles/a-deep-dive-into-end-fed-half-wave-antennas-originak

https://www.eeeguide.com/antenna-characteristics/

Colin Summers, MM0OPX. Check out his YouTube channel. Here are some links:
Using the 1002 core – https://www.youtube.com/watch?v=Xe0wvbOQeok&t=48s
Goodness of cores in general – https://www.youtube.com/watch?v=nZ-G4hJCTSM&t=3s
How to measure transformer insertion loss – https://www.youtube.com/watch?v=TZjY2Jim7fY&t=1s