A diaphragmless microphone for radio broadcasting

R. L. Jones: I believe we would all find ourselves in substantial agreement with Dr. Thomas in respect to the first four conditions which he sets down as those which must be met by a high quality telephonic reproducing apparatus. It is to be regretted, however, that he does not give data to show how well the glow discharge transmitter fulfills them: data as to its physical efficiency; frequency response characteristics; and its load capacity, or the degree of linearity with which it responds over a wide range of intensities. The general idea of a telephone transmitter depending upon ionic discharge is old,¹ but this is the first time, to my knowledge, that a telephone transmitter depending upon the phenomenon has been utilized practically. The world is eager for better tools of communication, and the impetus lately given by radio and public address systems stimulates interest. If the glow discharge transmitter fulfils even a part of the fundamental conditions better than other available types, it is probable, in spite of the high-voltage supply and other operating disadvantages, that it will have a certain field of use. In view of the present lack of data showing its performance under the variety of actual conditions, however, it remains for the future to reveal what place it has.