3D printable parts for building tape measure yagi antennas.
These files are based on an original design by Brian Zoraster (KA6ZED). All credit for the idea belongs to him, I just made some edits to fit different sized tapes and pipes.
Take a look at the Pacificon T-Hunt and Brian's design on Printables for more details.
Licensed under Creative Commons (4.0 International License) Attribution-ShareAlike. See the LICENSE file for complete details.
- 32” of PVC pipe. ½” or ¾” work well.
- 95” of measuring tape, preferably from a broken or unwanted tape measure.
- 1 printed driven element fitting
- 2 printed parasitic element fittings.
- 7 #4 ½” sheet metal screws.
- Coax cable with your preferred connector, cutting commercial coax patch cables in half is a great method for this.
- 5” of solid insulated wire for a matching element, PVC or enamel insulation is fine. Anything from 14 AWG through 20 AWG works well.
Cut four lengths of tape measure, 41 ⅜” for the reflector, 35 ⅛” for the director, and two lengths of 17 ¾” for the driven element. Round the ends of each section of tape and sand them smooth to make the antenna safer to handle. Make a place for soldering connections on one end of each driven element section by sanding off a bit of the paint on the back side of the tape.
Mark the center of your reflector element and slide it into one of the parasitic element fittings. Secure in place with a set screw. Slide this fitting over the pipe nearly to one end. The exact position is up to you, save room for a handle or your hand to hold the boom. Secure the fitting to the pipe with another screw.
Place one section of the driven element into each side of the driven element fitting. The areas you sanded to solder connections should be visible through the notches in the fitting. Secure both sections with set screws. Slide this fitting onto the pipe so that the driven element is parallel to the reflector and spaced 7 ⅜” (measured center to center) from the reflector element. Secure the fitting to the pipe with a screw.
Mark the center of your director element and slide it into the remaining parasitic element fitting. Secure in place with a set screw. Slide this fitting over the pipe so that the director is parallel to the other elements and spaced 12 ¾” from the driven element.
Strip ¼” of insulation from each end of the wire to be used for the matching element. Bend the wire into a U-shape with a ¾” gap. Solder each end of the wire to each of the driven element sections through the notches in the fitting.
Next attach your coax cable; strip back about ¾” of the outer insulation and separate the braided shield from the center conductor. Strip about ¼” of insulation from the center conductor. Twist the braided shield into a wire and check for shorts between the braid and center conductor before continuing. Solder the inner conductor to one driven element section and solder the shield to the other section. Use plenty of flux and a high wattage iron.
Finally add the matching element. Take your wire and form it into a U shape, strip off the ends and solder one to each of the two driven elements at the same point as the coax attachements. Since solder joints to the tape can be a little brittle you might consider adding some hot glue or other support here. That will make a break less likely but more difficult to repair. Your call on which is more important to you.
That’s it! Hook your new antenna up to your favorite antenna testing tool to check its performance. Adjust the spacing of the hairpin match and the position of the driven element fitting as needed to achieve low SWR in the frequencies you care most about.
A 70cm and a dual-band 2m / 70cm version of this build will be added here soon. In the meantime any of the myriad of yagi-calculators and designs online can help you design whatever antenna you want!
73, AI6YM