Radio instruments and measurements

The Bureau of Standards issued in March 1918 its Circular No. 74, entitled “Radio instruments and measurements.” The demand for this circular has been such as to warrant the preparation of a revised edition, work on which is at present under way. Owing; to the rapid growth of radio communication the appliances and methods used have undergone frequent and radical changes. In this growth progress has been made largely through new inventions and applications and comparatively little attention has been paid to the refinements of measurement. This circular contains information on the more important instruments and measurements actually used in radio work. Many of the subjects with which this circular deals are, or have been, under investigation in the Bureau's laboratories and are not covered in existing publications. No attempt has been made to deal with the operation of apparatus in sending and receiving. A number of corrections and revisions have been made in the present edition and the bibliography of radio publications has been considerably extended. This publication is not yet ready for distribution.