A MULTIPLE UNIT STEERABLE ANTENNA 



355 



and the coupling condenser (Fig. 10) alternately until the maximum 

 signal voltage appears on an indicating meter in one of the three inter- 

 mediate-frequency branches. The three-terminal coupling condenser 

 is an aid in this procedure since varying the coupling imposes only a 

 slight variation in the capacitance across the coil. When the indicating 

 instrument is a square-law vacuum tube voltmeter with the main 



Fig. 1 1 — Close-up view of high-frequency panel with cover removed. The beating 

 oscillator supplv line originates in the upper right-hand corner. It supplies the six 

 detectors with 'equiphase and equiamplitude voltages. Plug-in coils fit into the 

 compartments covered by the six circular doors. Micrometer heads which are used 

 to adjust the six tuning condensers appear. The coaxial patch cords appear at the 

 extreme left. 



