INSTRUMENTS FOR THE NEW TELEPHONE SETS 



341 



and the caps relative to the handle is unnecessary. The spacing 

 between the transmitter and receiver is such that the handset can be 

 used with the existing type of desk mounting as well as with the new 

 combined set. 



Desk Stand and Wall Set Applications 

 The photograph, Fig. 1, also shows the new transmitter and receiver 

 unit adapted to desk stand and wall set use. Cross-sections of these 

 instruments are shown on Fig. 3. The faceplate, mouthpiece and pro- 



TRANSMITTER 

 UNIT 



Fig. 3 — Cross-sections of the transmitter and receiver for desk stands and wall sets. 



tective grid of the transmitter are combined in one phenol plastic part 

 which is so designed as to reduce cavity resonance to a minimum and 

 provide response characteristics essentially the same as those of the 

 handset transmitter. On the other hand, the mouthpiece is sufficiently 



