Saturday 16 June 2018. The weather around Canberra is cold wet and windy as a deep low, 994 hPa passes over south-east Australia. Today’s top ambient temperature is 9 degrees C while the feels-like is a chilly 2 degrees C. Tomorrow’s forecast is for a chance of snow down to 800 m ASL. My QTH is at 620 m ASL, we may see snow flakes around Canberra suburbs.
Today, with some spare time on my hands and no desire to spend time outdoors, I decided to build a portable lightweight 70cm 432.2 MHz Yagi for hilltop activations. Method of construction is the same as my homebrew 2m 4el DL6WU yagi, predicted gain is 9.8 dB. Reflector and director elements are 3.18 mm aluminium rod. The driven element is 2.5 mm solid copper wire.
When hiking, all elements are safely stored inside the plastic boom. Secure one end-cap with glue and allow the opposite end end-cap to be removed by hand. I’m looking forward to testing the antenna when weather conditions improve. 🙂
Adjust element spacings to fine tune the resonant frequency while monitoring the antenna analyser for a low VSWR. Mark all element positions with a permanent marker. I used a hacksaw blade the mark the external surface of the plastic pipe.
Antenna dimensions by VK5DJ yagi software
73 Andrew VK1AD
Published: 16 June 2018
Last Update: 17 June 2018 – Antenna Analyser AntScope data