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