Hi Mauro, I have no hands on experience with this antenna, but simulations by experts have shown that one should go for a ~900 Ohm termination resistor and at least 50m length if you want to keep los
Hi Mauro Google search ttfd antenna returns About 3,390 results (0.68 seconds) Here are a few links. http://www.packetradio.com/t2fd.htm http://hf-antenna.com/015/ https://en.wikipedia.org/wiki/T2FD_
This type of aerial goes back to at least the 1950's and had 3 wires in a sloping config making it broad band with a term resistor Called a SFTD and used commercially G3KEV