Let's Build an EFHW Antenna

If you attended Field Day 2022, you may have been one of the students that learned how to build an end fed halfwave 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.  Building antennas is a fun learning experience for any ham operator and one that will serve you well for many years.  Knowing how to build an antenna also saves you a bit of money from buying the commercial ones online that can range from $40 up to $180.

It is just an overall good skill to have under your belt.

As promised in the class, I am making the build details available to you if you so choose to build one.  They are not hard to assemble and with a few minor skills you are going to end up with a very nice antenna.

Supplies for building an EFHW Antenna

Some of the items below are links to purchase supplies from reputable dealers
NOTE on 3D Printing the Winder

Living in a hot climate area like Texas, things tend to melt.  I highly suggest that if you are going to 3D print this, that you use Tough PLA.  It is rigid and heat resistant.  That last thing you want is for the SO-239 to fall off your antenna while operating.  I used 100% infill on my print and it took my Creality CR10-S about 7 hours to print the winder.  No adjustments need to be made and you can print it as it.  However, if you wish to experiment and are good with 3D software like Tinkercad, feel free to modify it to your needs.

Tools You Will Need

Build Instructions


  1. Measure antenna wire 4.5 inches and double over
  2. Using larger of the ring terminals, pass wire through and loop over ring
  3. Crimp
  4. Attach the loose end wire to the smaller ring terminal
  5. Crimp and solder


  1. Measure out 8 inches of magnet wire and fold over
  2. Measure up 2.5 inches of the loose end wire and bend 90 degrees (see video), carefully hold with pliers and twist the loop
  3. Snip off loop after twist is complete
  4. Wind Toroid keeping your windings tight to the toroid and NOT overlapping or kinking up the mag wire(see diagram)


  1. Install SO-239 to wire winder paying attention to direction of ground tab
  2. Mount Toroid with zip ties
  3. Measure toroid wires to each of the SO-239 terminals, make your cuts
  4. Scrape off magnet wire coating on all three wires (TX, GND & ANT)
  5. Snip capacitor and prepare for solder
  6. Solder toroid twisted wires and capacitor to ground ring
  7. Single wire and capacitor go to center connector on SO-239
  8. Hot Glue SO-239 connections and wire (Optional)
  9. Attach Antenna wire to antenna frame winder (See Video for Sequence)


You should be good for 40, 20, 15 & 10 Meters.

Enjoy your EFHW Antenna!