This is a little article I wrote some years ago on the T2FD. It's not intended to describe the theory of the antenna, but rather my approach at the time to its practical construction. It may be of interest to readers of this forum.
The original web link no longer works, so I've moved the pdf to my Box/com cloud. You can access it via the Radio Resources page on my blog site.
http://medxr.blogspot.com.au/p/radio-resources.html73
Rob Wagner VK3BVW