CARD TRANSLATOR FOR NATIONWIDE DIALING 1053 



merit. The relays in operating lock to ground and thereby extinguish 

 the main gap discharges thus increasing the hfe of the gas tubes. Those 

 channels which have been blanked out will not have the control gaps of 

 the gas tubes broken down. Therefore when the 130 volts is applied, the 

 relays associated with the darkened channels will not operate. The 

 operation or non-operation of the relays in the associated equipment 

 completes the function of the channel circuits. 



The capacitor and resistor network at the main anode of the tube is 

 to prevent transients due to the operation of other channels from falsely 

 firing the main gap of a dark channel. 



CHANNEL PACKAGES 



The phototransistor is mounted in a metal tube along with a lens 

 that focuses the colliminated light on the transistor. Fig. 10 is a cutaway 



LENS 



COLLECTOR' ^GERMANIUM 



BLOCK 



Fig. 10 — Cut away view of phototransistor. 



view of the 3A phototransistor showing the relationship of the lens to 

 the transistor. To mount in the translator, the tube is slipped into an 

 accurately positioned hole and clamped in place using the slotted ear. 

 This mechanical fastening is also the ground connection. The output 

 lead from the collector is attached using a slip-on connector. 



The amplifying transistor, transformer Tl, varistor V, the resistor 

 and two capacitors of the amplifier are packaged in a convenient "plug- 

 in" unit. Fig. 11 is a photograph of these amplifiers. As shown, the 

 transistor is mounted under a removable cap on the package so that it 

 may be conveniently replaced if necessary. 



The gas tube, transformer T2, and the associated resistor and capaci- 

 tor are also assembled as a packaged unit. 



TRANSLATOR CIRCUITRY 



The card translator is mounted on an associated translator table as 

 shown in Fig. 12. The translator table contains the transistor amplifiers 



