A MULTIPLE UNIT STEERABLE ANTENNA 



359 



pensated and any other desired amplitude adjustments made. The 

 photograph of Fig. 15 shows the monitoring or exploring branch whose 

 steering shaft is motor driven at one revolution per second. 



Before leaving the subject of phase shifting it may be well to dis- 

 tinguish between phase shift and delay as here used. All electrical net- 



Fig. 15 — Phase shifting panel of the monitoring branch. Only five of the six 

 phase shifters are rotated for steering purposes. They are geared to the steering 

 shaft in ratios of 1 : 1, 1 : 2, 1 : 3, 1 : 4, and 1 : 5. 



works, except for certain highly distortive ones, possess a phase-fre- 

 quency characteristic which is such that higher frequencies have their 

 phases retarded with respect to lower frequencies. The ratio of the 

 ncrement of phase retardation to the increment of frequency, i.e., the 



