A tracking index cathode ray tube circuit is described, comprising tracking means connected to a shadowmaskless tracking cathode ray tube for deriving a tracking signal therefrom, where the tracking means comprises a modulator demodulator circuit. The tracking signal from the CRT tube is thus modulated, AC coupled to a low voltage and demodulated to obtain a baseband tracking signal for use as a control signal for the electron beam spots on the screen of the CRT tube.