Phase-shifting and -inverting circuit for colour TV receivers - has transistor phase-splitter feeding half line-freq alternating phase shifter

The phase shifting and inverting circuit, for colour television receivers generates a first signal alternating in phase by 180 deg. and a second signal of constant phase shifted by 90 deg. w.r.t. the original constant phase signal from which both the signals are derived. The colour carrier is applied to a phase-splitting circuit to give two oppositely phased output signals. These signals are applied over d.c blocking capacitors to a phase shifting circuit consisting of two series coupled iodes supplied at their junction with a half line-frequency signal and at their outer points with the two 180 deg. shifted signals. The alternately-inverting R-Y signal appears at the phase shifter output, whilst the 90 deg. shifted B-Y signal appears at the output of a 90 deg. phase shifter (27) coupled across the phase-splitter output.