Hams with directional antennas want to know where true north is from their location. Rotors and beams need to be aligned and you might want to erect a directional but stationary antenna pointed at Europe or a rare DXpedition. The heading for your antenna, in degrees, is with respect to true north or the northern end of the earths rotational axis.

The shadow cast by any plumb (perpendicular to the earth's surface) object will point to true north at local or solar noon. Solar noon is the time when the sun is at its maximum elevation in the sky and it varies with location and time of year. Find your local noon.



How accurately does a directional antenna need to be pointed? Depending on construction and height above ground, a typical 3 element HF yagi can have a 3db beam width in the range of 60 to 90 degrees. At the other end of the scale, a long boom UHF yagi with 40 elements or more might have a beam width approaching 15 degrees. Most rotors pointing accuracy is no better than about 5 degrees. The HF yagi might be off course 20 degrees or more before you begin to hear a difference. The same error for the UHF long boom antenna could easily put a weak to moderate signal completely below the noise. To the question of how much time and effort to invest in achieving pointing accuracy, only you can be the judge of the point of diminishing returns for your system.