DIY 434Mhz Antenna

 

434 4 element yagi

434 4 element yagi

If you would like to make your own 434Mhz yagi, here is some info to help you.   It is up to you how many elements you use.  I use RG-58 because of it’s VF and Impedance.  The  VF lets the balun be shorter.  The image left does not have a balun.  It is a functional design, but a balun could help some.  Let me know if you have any questions.
Brian

 

Materials

  1. Aluminium arrows (22/64″ or 8.73125mm)
  2. 1 inch wide non-conductive material for the boom
  3. RG58 coax
  4. 50 ohm BNC connector or SMA-Male (whatever your radio uses)
  5. Balun – Here is a PDF with the info to create your own balun using RG-58 (Balun_for_434_MHz_using_228_mm_loop_of_RG-58)
  6. Tools for bending and soldering

Antenna Details

These antenna designs were calculated using VK5DJ’s Yagi Calculator

I like 3 elements for best performance for the size but also made a 4 element.  For the boom, if you do not have a non-conductive material (like pvc conduit) you can build insulators (13mm or greater) to mount the elements to.

3 Elements
Frequency : 434 MHz
Wavelength : 691 mm
Rod Diameter : 8.73125 mm
Boom Diameter : 25 mm
Boom Length : 230 mm
Elements : 3
Gain : 6.9 dBd (approx.)
————————————————————-
Reflector Length : 334.4 mm
Reflector Position : 0 mm
————————————————————-
Dipole Length : 320.2 mm end to end
Dipole Position : 138 mm from reflector
————————————————————-
Director #1 Length : 289.9 mm
Director #1 Position : 51.8 mm from Dipole
————————————————————-
Directors / Parasitics are isolated.
Please choose an isolater thicker than : 13 mm

Positions are center to center measurements.

4 Elements

Frequency : 434 MHz
Wavelength : 691 mm
Rod Diameter : 8.73125 mm
Boom Diameter : 25 mm
Boom Length : 345 mm
Elements : 4
Gain : 8.6 dBd (approx.)
————————————————————-
Reflector Length : 334.4 mm
Reflector Position : 0 mm
————————————————————-
Dipole Length : 320.2 mm end to end
Dipole Position : 138 mm from reflector
————————————————————-
Director #1 Length : 289.9 mm
Director #1 Position : 51.8 mm from Dipole
————————————————————-
Director #2 Length : 286.1 mm
Director #2 Position : 124.3 mm from Director #1
————————————————————-
Directors / Parasitics are isolated.
Please choose an isolater thicker than : 13 mm

Positions are center to center measurements.

October 2018

Sun Mon Tue Wed Thu Fri Sat
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31