Belgium 



81 



M4 falls. The presence of these ring-off indicators (one at each 

 end of the line), which, as well as the phonic call coils, have to be 

 talked through, is a bad feature of the system. The plug F5 (fig. 

 1 8) is in connection with the wire 02 by its second contact, and 

 through a i,ooo-ohm indicator M5 to earth. Therefore when F5 

 is in a trunk jack the test line of the local subscriber is in con- 

 nection with C2, now insulated, and through the indicator M5 to 



JVI5 



C2 



FIG. 18 



earth. When the calling subscriber has a double line, the con- 

 nection when established comprises (if the operators have agreed 

 to use junction wire 03) F5, 03, to jack J3 (fig. 17), plug F2, jacks 

 J4 15, plug FI, coils PI P2 of phonic call, jacks ji J2 and wi W2. 

 In this case the indicator MI, which is in shunt with the phonic 

 call coils, acts as ring-off, The test is managed as before. The 

 translator is cut out, but the phonic call coils still have to be 



G 



