Perfect weather to erect all antennas

November starts with 2 weeks of mild weather, with lots of sunshine and no rain. This means that the corn field is rather dry now and easy to walk on. In the first weekend I put lots of tonkin poles in the ground to mark all antennas. I also rolled out the HEDZ (100m) and the beverages (2x 80m). The beverage is nearly ready already, including matchbox and feeder. Wytske helped me to erect the 15m center pole of the HEDZ. Within a couple of hours a kestrel already liked the pole and is now regularly seen sitting on the top.

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Automatic antenna tuner using an Arduino

Introduction

OLYMPUS DIGITAL CAMERAThe Arduino board is a fantastic tool for rapid prototyping, and can help radio amateurs in lots of homebrew projects. I wanted to demonstrate that it is very easy to build an automatic antenna tuner with the Arduino. I connected an old SWR meter to one of my Arduino boards. Furthermore I build a simple L-tuner with a fixed coil and a rotating capacitor (400pF). The capacitor is driven by a servo, also connected to the Arduino. By doing a full sweep with the capacitor, the Arduino tries to find the position with the lowest SWR. After the sweep it turns the capacitor to that position. You can view the video below to see the tuner in action. Mind the SWR meter (right needle) in the back while the capacitor is rotating. — more →