Radio-Compass Testing with Small Shielded Enclosures

A method is described by which radio compasses may be tested using small shielded enclosures (24 by 24 by 24 inches for many loop types) instead of screen rooms. This procedure results in economies of cost and space, as well as providing portability and rapid setup. Application of accepted methods of determining field strength for calibration purposes is discussed. Enclosure modifications for utilization of flush loops and the incorporation of rotation facilities for loop bearing-accuracy tests are also covered. Some approaches to enclosure design and construction are described, and examples of different types of existing and proposed units are shown. The possibility of using a small enclosure within an existing screen room as an aid in curing serious noise and interference problems, as an inexpensive substitute for renovating or replacing the screen room, or as a means for locating sources of noise or other disturbances, such as stray fields and RF leakage from signal generators, is also described.