t; a control circuit for controlling the amount of load adjustment and drive adjustment such that a tuning range of said delay lineis equal to (M/2)(t.sub.dl+t.sub.dp) where M is a number of taps, t.sub.dl is a range of delay provided by said first portion and t.sub.dp is a range of delay provided by said second portion; a phase detector for producing signals for input to saidcontrol circuit; and