In {TAIL ~ operation}, {HEAD ~ the variable delay element} 30 provides a variable delay whose magnitude is directly related to the composite of the degrees of operation of the differential sections D1 and D2 
In
In { TAIL ~ operation } , { HEAD ~ the variable delay element } 30 provides a variable delay whose magnitude is directly related to the composite of the degrees of operation of the differential sections D1 and D2
REL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH