An automatic recorder of aerial radiation diagrams

The requirements of a machine which will plot the radiation pattern of aerials automatically are briefly outlined, and a design that meets these requirements is then described. The basis of the design is the automatic comparison of a local audio-frequency signal, and a signal of the same audio-frequency proportional to the unknown radio-frequency signal. Such a system has the advantage of being readily adaptable for a wide range of radio-frequencies. Arrangements are made for mounting large aerials at various heights and for the presentation of results in different ways. Facilities are also provided for indicating the relative field intensity when it is desired to plot by hand.