This simulation illustrates the RF pattern (using an unmodulated carrier or Continuous Wave) for an in-phase localizer antenna pair and the effect of antenna a-spacing. You can click and drag the right antenna to widen the pair.

Due to Flash Player emulation limitations, the rotary knob for adjusting the transmission line electrical length of the right antenna is not functional. So by default, the configuration can only represent an in-phase antenna pair, producing the CSB pattern. If the right antenna phase were adjustable by 180 degrees, a null would appear on the centerline, representing the SBO pattern.

These phase relationships are managed through the antenna distribution unit and the length of the transmission lines. You can click and drag the green or blue dots (observation points) to view the individual antenna signals and the resulting composite signal that emerges when they "space modulate". See how they add or subtract depending on your location.