Contrasting early radio direction finding instruments with the modern type, Mr. Miller said that concurrently with the research and development work necessary to analyze and produce cures for the sources of error to which the apparatus was at first subject, much work had been done in producing more compact instruments of higher all round performance. A modern direction finder was highly sensitive and selective, and was capable, under good conditions, of giving bearings with an accuracy of plus or minus % per cent. over a distance of several hundred miles.
Dealing with direction finders used in aeroplanes, Mr. Miller said that the problems confronting the designer of an aircraft direction finder were somewhat similar to those connected with marine instruments, except that rigid restrictions as to size and weight rendered light and compact construction essential. In addition, the high noise level on aircraft rendered the provision of a very sensitive receiver desirable, although this was not so evident in modern "sound proofed" machines.
Most of the present development work was being carried out on short aves, since the accuracy and sensitivity of the modern long wave direttion finder was now adequate for all ordinary equipment. There were, however, a number of recent developments In long wave direction finders, although some of these would appear io be largely of theoretical rather than practical interest. Amongst development work now being undertaken was the distant control of direction finders, and work was also being carried out on systems of tele-control, with the idea of operating the direction finder over distances of several miles.
Text read from the printed page and cleaned; old type leaves the occasional error.