]fEASr KING SYSTEM lOli VIDEO 



lil 



from tlic (liuls of the phase-shifter and attenuator or from the scales of 

 the incHcalors. 



ACKNOWI.KDC.MENT 



Acknowled^mient is due nienihers of the j,^roui)S sui)ervised by Mr. E. P. 

 Felch (electrical) and Mr. W. J. Means (mechanical) for contributions to 

 the design. 



APPENDIX 



The Ph.ase Discriminator Bridge 

 The general [ihase relationship of the discriminator is shown in Fig. 13a. 



(a) 



lb) 



Fig. 13 — Phase bridge vector relationships. 



Using complex vectorial notation, 



(4) Es = (1 •2)(£ie^'^' + E^J"') 



(5) Eu = (1 '2){E,e''' - eJ""-) 



Hence for <p = -kI -\- nw where ^ = <pi — <p2 and ;; is an integer, 



(6) \Es\ = \Ed\ 



Stated in words: The amplitudes of Es and E,j are equal if the relative 

 phase angle <p is equal to ^^0°, 270°, 450°, etc., independently of the ampli- 

 tudes of El and £2 (Fig. 13b). 



Inequality of Es • and | Ed \ can be utilized to measure phase departure 

 from ip = TT, 2 -\- HIT 



From (4) and (5), 



(7) 1 Es I = (1/2) V|£i|' + 2|£i£2|cos^ + {E^]^ 



(8) 



En\ = (1'2)V'|£,|- - 2\EiE,\cos<p ^ Ie,]' 



