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If you attended Field Day 2022, you may have been one of the students that learned how to build an end fed half wave Antenna and actually got to build one and take it home. For those that were not able to do so, this page is for you.
This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. It is a resonant Half wave on 80m (3.5MHz) therefore also resonant on second, third, and fourth harmonics, etc.
To help new hams prepare for the exciting world of HF opening up during Cycle 25, ARRL has partnered with HF Kits to bring you this easy-to-build four-band antenna kit: an end-fed half-wave (EFHW) antenna.
antenna is based on any number of parameters: specifically, the frequency or band of frequencies, location, directivity, and intended power range. This paper discusses some of the more important aspects of the End Fed Half Wave (EFHW) dipole antenna. The frequency band is HF (40 meters), and the intended power is 100 watts.
Par EndFedz® Antennas are End Fed Half Wave (EFHW) antennas with the match box coax connection at the end of the wire, for convenient and quick stealth portable operations. These single-band and multi-band antennas can be mounted horizontally, vertically, or as a sloper.
This is exactly the convenience the end-fed half-wave antenna (EFHWA) offers. It does not require an extensive ground like a big ferrous vehicle body, only a short counterpoise wire. It is a favorite of Summits-On-The-Air (SOTA) activators and ARES/RACES that roll it up into a backpack or toss it in an emergency go kit.
half-wave antennas. An end-fed half-wave (“EFHW”) antenna has a very high feedpoint impedance, often 1000 to 5000 ohms (depending on the diameter). The radiation pattern on the fundamental frequency (where the antenna is 1/2 wavelength) will be similar to the same wire fed in the center as a dipole (but this is not the case on harmonics).
End-fed half wave antennas are best for temporary antennas using low power and batteries, far from power mains and noise sources. They are more prone for problems near noise sources or consumer gear, and can easily exceed FCC RF exposure limits with surprising low power levels.
The EFHW antenna is one of amateur radio’s oldest antenna designs. EFHW stands for “End Fed Half wave” and was first introduced way back in 1927 by the Austrian radio amateur, Dr. Josef Fuchs, OE1JF. Later the antenna got name “Fuchs Antenna.” It was patented in 1928, published in QST magazine and subsequently forgotten for many years.
Emergency Amateur Radio Club of Hawaii (EARCHI) marketed a matchbox-kit for a 6-40 mtr multi-band end-fed antenna. Uses non-resonant antenna (Recommended antenna wire length: 24-30 ft (60 ft max) and powdered iron toroid, efficient transmission line transformer.