SUBMARINE TELEGRAPH CABLES 435 



Mechanical Details of Amplifier and Relay Control Desk 



The construction of the amplifier and relay control desk is shown 

 in the accompanying figures. Fig. 2 is a front and Fig. 3 a back view 

 of the amplifier in its cabinet, Fig. 4 is a back view of the panel frame 

 removed from the cabinet and Fig. 5 is a front view of the relay control 

 panel associated with the amplifier. Mechanically the amplifier 



Fig. 2. 



consists of a frame of brass angles supporting on its front face four 

 large hard rubber panels and sixteen small ones. The four large 

 panels are mounted on the upper part of the frame, and hold the 

 switches and the meters which it has been found desirable to provide 

 in the filament and plate circuit of each vacuum tube. The adjustable 

 elements of the amplifier interstage shaping networks are contained in 

 the sixteen smaller panels mounted in the lower part of the framework. 

 Each of these panels is a complete unit, comprising either a variable 

 condenser, a variable resistance, or a switch for the adjustment of an 



