This design has been around for a long time and we thought it woudl be good to have a 2m Yagi antenna to use to find the tracker if all our other tracking methods fail

This design was by Joe Leggio WB2HOL who has a great write up here on how to build one so I wont cover that here. We also used Martin E. Meserve website on VHF/UHF Yagi Design.

We used the website to get the exact dimensions of the reflector, driven element and parasitic elements.

2m Tape Measure Yagi

2m Tape Measure Yagi

The driven element needed a hairpin match to enough  inductance to cancel the capacitive reactance of the driven element.

A hairpin match and feedpoint on the driven element on the tape measure yagi

A hairpin match and feedpoint on the driven element on the tape measure yagi

With the use of the Kenwood TH-D72A and a SWR meter we were able to tune the antenna to SWR of 1.05 at 145.175Mhz

Using S/SWR meter to tune 2m Yagi antenna for 145.175Mhz APRS frequency

Using S/SWR meter to tune 2m Yagi antenna for 145.175Mhz APRS frequency