For those who don't know a 1.5 tick pulse can travel through redstone torches & comparators, while still having the properties of a standard 1 tick pulse. It can be used as a 1 tick inverter, sending it through a repeater will then convert it back to 1 tick.
It may not actually be a 1.5 tick pulse, all i know is it has neither properties of a standard 1 tick or 2 tick pulse.