70cm 4 Elements Yagi @ 409Mhz usable frequency 406-412Mhz
Antenna specifications
Antenna Bandwidth: 406-412Mhz
Antenna gain @ center frequency: 7.16dBi
Beam width: 66° Horizontal / 108° Vertical
Front/Back ratio: 14.4dB
4 Elements Yagi 70cm UHF Antenna Materials List
1. 1″ X 0.5″ Rectangular Aluminum tubing for the boom
2. 3/8″ Aluminum tubing for antenna elements
3. 1cm Outside diameter antenna tubing for elements holder
4. 1pc SO239 connector
5. Pop rivets / Rivet tool
6. #12 AWG Copper wire with insulation (12″for Gamma match)
7. Soldering iron
8. 8pcs Stainless steel nuts and bolts 20mm length 3mm diameter
9. 1, Butterfly nut and 1 bolt 18mm length 3mm diameter
10. Aluminum plate 0.5mm thickness
11. Collapsible tube (shrinkable tubes)
Antenna Measurements

Download the PDF document here
Build the gamma match for this yagi here. Although the gamma match is originally for 3 elements yagi antenna UHF this will also work with this 4 elements UHF yagi antenna.
Expected antenna pattern generated using 4NEC2
Antenna combined pattern
Horizontal pattern
Vertical Pattern
Antenna Pattern on the low band 406Mhz
No skewing detected on the antenna pattern as generated by 4NEC2

Antenna Pattern on the high band 412Mhz
Minimal skewing on the 412Mhz antenna pattern as generated by 4NEC2
Complete Antenna Analysis using NanoVNA and N1201SA antenna analyzer