c. The transmitter unit is mounted in a handset, as shown in the disassembled view of figure 20. It is held in
place by the transmitter cap, along with contact springs which press against its contact. The unit may be removed for
servicing by unscrewing the plastic cap or mouthpiece.
d. An improved type of carbon transmitter is shown in figure 12. The frequency response of this unit has been
improved by use of an acoustic network which couples the back chamber of the diaphragm through an acoustic resistance
to the cup chamber. Woven rayon fabric is used for the acoustic resistance material. This transmitter, in addition to an
improved frequency response, has a high modulation efficiency. Note that the diaphragm of this transmitter is clamped
rigidly at its outer edge, whereas the diaphragm of the element in B, figure 11, is floated between paper spacers.
FIGURE 12. Modern Transmitter
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