Amateur Radio – End fed Halfwave antenna – Web resources and links
An end-fed half-wave (EFHW) antenna is a type of radio antenna that is a half-wavelength long and has its feed point at one end. This makes it a very simple and compact antenna, and it is often used for portable or temporary applications.
EFHW antennas are typically made of wire, and they can be fed with either a coaxial cable or an open-wire transmission line. The feed point impedance of an EFHW antenna is typically very high, so it is often necessary to use an impedance matching network to match the antenna to the transmitter. EFHW antennas are not as efficient as some other types of antennas, but they are very easy to build and use. They are also relatively insensitive to ground losses, which makes them a good choice for use in areas with poor ground conductivity.