New Western Electric Transmitter

The White transmitter was the prototype of a large number of others embodying the same features of having the rear electrode mounted in a stationary cup or chamber and the front electrode movable with the diaphragm, a washer of mica or other flexible insulating material serving to close the front of the electrode chamber and at the same time to permit the nece ary vibration of the front electrode with the diaphragm. IMG:384091999325875926_fig042_t.gif.png:Illustration_ Fig. 42. New Western Electric Transmitter Fig. 42. New Western Electric Transmitter View full size illustration. One of these transmitters, embodying these same features but with modified details, is shown in Fig. 42, this being the new transmitter manufactured by the Western Electric Company. In this the bridge of the original White transmitter is dispensed with, the electrode chamber being supported by a pre ed metal cup 1 , which supports the chamber as a whole. The electrode cup, instead of being made of a solid block as in the White instrument, is composed of two portions, a cylindrical or tubular portion 2 and a back 3 . The cylindrical portion is externally screw-threaded so as to engage an internal screw thread in a flanged opening in the center of the cup 1 . By this means the electrode chamber is held in place in the cup 1 , and by the same means the mica washer 4 is clamped between the flange in this opening and the tubular portion 2 of the electrode chamber. The front electrode is carried, as in the White transmitter, on the mica washer and is rigidly attached to the center of the diaphragm so as to partake of the movement thereof. It will be seen, therefore, that this is e entially a White transmitter, but with a modified mounting for the electrode chamber. A feature in this transmitter that is not found in the White transmitter is that both the front and the rear electrodes, in fact, the entire working portions of the transmitter, are insulated from the exposed metal parts of the instrument. This is accomplished by insulating the diaphragm and the supporting cup 1 from the transmitter front. The terminal 5 on the cup 1 forms the electrical connection for the rear electrode, while the terminal 6 , which is mounted on but insulated from the cup 1 and is connected with the front electrode by a thin flexible connecting strip, forms the electrical connection for the front electrode.