Building an End Fed…
The end fed half wave is a type of antenna system intended for use on the amateur radio HF bands, typically 80 meters through 10 meters. Its design is simple - a wire, a transformer, and a feed line. There are a number of different types of end fed wire antennas and they can be deployed in many different configurations. The end fed half wave antenna has a radiator that is approximately one half wavelength of the lowest frequency it is intended to be used on - give or take a bit for adjustment within the bands. In addition to a wire that is half wavelength, this antenna also has a transformer that brings the high impedance of a wire in free space down to the 50Ω that our radios crave. EFHWs are often referred to as "no-tune" antennas, because they tend to have an SWR that is usable without tuning across the primary band and its harmonics. The transformers that do this matching are often called "baluns" - but I'm not sure if that's correct. A balun is traditionally used to match a…