This antenna is actually calibrated exactly for LoRa Meshtastic communication.
If built precisely, it delivers a SWR < 1.2 centered at 869.500 MHz.
Required 3D Printed Parts
This model is designed to be highly adjustable, allowing it to move up and down in 15-degree increments. To fit different installation needs, there are 5 different arm lengths available to choose from. Depending on how you want your antenna to move, please print the following files:
- For Up/Down Movement Only: Print the body, an arm (choose one length), 2x nut, the solder cap, and the wall hanger no360 adapter.
- For Up/Down AND Left/Right Movement: If you want to adjust the antenna left and right (also in 15-degree increments) in addition to up and down, print the body, an arm (choose one length), 2x nut, the solder cap, and the wall hanger with 360 adapter.
Post-Printing Instructions
Inserting the Antenna Elements
After printing the antenna body, insert stripped 1.5mm single-core NYA copper wires into the integrated channels:
- 1 x wire for the Reflector
- 2 x wires for the Dipole elements
- 2x M3 x 12mm hex-head bolts
- 2x M3 nuts
These bolts will be used to secure the antenna in place through the mounting points.
Plastic zip ties
Plastic zip ties will be used to secure the coaxial cable when forming the "Ugly Balun" behind the dipole junction box. They help maintain the shape and position of the cable during winding.
Use tweezers or a fine-tipped tool to push them into place.
Soldering the Coaxial Cable
- Strip about 1 cm of the outer jacket of a 50Ω coaxial cable (RG174/RG316).
- Twist the braided shield into a single wire, and strip 3 mm of insulation from the live (center) conductor.
- Pre-tin both the braided wire and the live wire with solder.
- Soldering:
- Live wire → Top Dipole
- Braided wire (Ground) → Bottom Dipole
- Do not connect anything to the Reflector.
⚠️ Warning: Avoid short circuits by keeping the insulation intact and keeping the braided strands separated from the live wire.
Making the Ugly Balun
- Wind the coaxial cable into 3 tight turns right behind the dipole connection area to form an "Ugly Balun".
- Secure the loops using plastic zip ties in the notched slot provided on the model.
⚠️ Warning: Do not pull on the cable while wrapping — you might break your dipole solder joints.
🧪 Sealing the Antenna
- After finishing the assembly, apply a two-component epoxy over the exposed copper wires, the soldering area, and the solder cap. You can use something like a thermal paste spatula to spread it evenly, then let it dry.
- Doing this will give you an "immortal" antenna that can withstand all kinds of outdoor weather conditions!
🔌 RF Connector Assembly
- Cut the coaxial cable to your desired length and solder an appropriate RF connector (SMA, BNC, etc.).
- If you are using a pre-made cable with one connector already attached, solder the other end directly to the antenna and shape your balun accordingly.
A Final Note ❤️
This antenna is not just another quick print; it is the product of serious trial, experimentation, and real-world RF testing. I spent a lot of time tweaking the dimensions, optimizing the feed point, and ensuring that even amateur users can build it with confidence.
Please consider showing your appreciation by liking, commenting, or sharing this project — your feedback keeps this kind of work alive and growing!
OZKAN
