Building a 137 Mhz QFH antenna
Making a Quadri Filar Helix antenna
Original concept
F4BPP's improvements
- Use 6 mm diameter raw aluminium full pipe.
- Remove 8 elbows to make the junction with the antenna elements by bending the pipes.
- Only 4 junctions with 8 mm diameter raw aluminium hollow pipe to avoid impedance loss.
- Coaxial cable protected inside the 32 mm PVC pipe.
- Use electric dominoes to connect the cable to the antenna to avoid drilling pipes and ensure better contact between the cable and them.