Build a 157.000 Mhz 4 Elements Yagi for VHF

4 Elements Yagi for 157.000 Mhz

This antenna is 4 elements yagi built for the frequency 157.000 Mhz, in the Philippines most of the users of this frequency bands are Government Organizations, LGU’s, Civic Groups, Fire volunteers and the like. Although most of the requested antenna designs fall on the Amateur Band (144.000 Mhz to 146.000 Mhz) frequency. I decided to published the details of this antenna although not frequently requested. The details of the build is similar to building the 4 Elements Yagi for Amateur Frequency. Elements measurements and spacing are of course adjusted to resonate properly on the 157.000 Mhz band.

Antenna Specifications

Antenna Center frequency 157.000 Mhz
Lowest usable band 152.000 Mhz
Highest usable band 160.000 Mhz
Antenna Gain: 9.52dBi
F/B ratio: 9.87dB
Beamwidth: 60° Vertical / 24° Horizontal

Expected Antenna Pattern Generated by 4NEC2

Antenna Pattern Vertical

Horizontal Antenna Pattern

Antenna Measurements

Download PDF Document antenna measurements here.

Material Listing

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 Matching / Gamma Match

Finished Antenna Testing

Antenna Calibration Video using NanoVNA

SWR response on the center frequency as confirmed by N1201SA