192 THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1951 



Fig. 12 — M-type and MF type phantom loading units. Before and after placement in 

 their unit shielding containers. M-type unit above the MF-type unit, "a" designates mid- 

 get inductance coils (used in crosstalk adjustments); "r" designates midget resistors 

 (used in crosstalk adjustments). The loading units shown outside the containers are not 

 the same as those shown inside the containers. , 



a function of coil size. For the most important types of loading, the increases 

 in attenuation that result from the higher coil resistances are in the range 



