EFHW Antenna Winder and Enclosure

The EFHW Antenna

EFHW (End-Fed Half-Wave) antennas are popular among amateur radio operators, especially for outdoor activities like SOTA (Summits on the Air) or POTA (Parks on the Air). You can find general information about this antenna type online, e.g. here

The enclosure is designed for a 1:49 transformer (available as a kit from HB9ZHK). If using a different transformer, ensure it fits the enclosure, as space is limited.

Additional materials needed:

• 4 screws (M2.5x6 or M2.5x10) to fix the lid
• 1 self-tapping screw (approx. 2x5 mm) to secure the circuit board (or use a blob of hot-melt glue as an alternative)
• Antenna wire (type and color of your choice; length depends on the operating frequency – must be a half wavelength or an integer multiple of it. See the wire length table on the HB9ZHK website for guidance.)
• Thin strings to secure the ends of the wire to nearby objects (like trees or bushes)
• A short length of coax cable with appropriate connectors (e.g. BNC) to connect the antenna to your radio

Tips for use:

• The wire and strings can be conveniently wound around the winder. Using a figure-eight winding pattern helps prevent tangling and kinks.
• Use the strings to tie the coiled-up wire to the winder. This prevents it from uncoiling while in your backpack.
• Adding a WAGO clamp to the side of the enclosure allows for easy wire replacement in the field without tools.
• If you make winders for different bands, use different-colored lids to tell them apart. Adding a label with the bands on the winder also helps.

EDIT: I could not upload gcode, says “unsupported code” ?!?