S-A AW series of hubs:
Gear 1 to 2: 7.4mm
Gear 2 to 3: 11.2mm
Another thought: Gear 2 must be aligned. Gear 1 happens when the cable is taut. Gear 3 happens when the cable is slack.
Of the current production, the RS-R*3 series, the S3X hubs and the CS-R*3 series Sturmey-Archer three speed hubs have different cable pulls than the AW series hubs.
HTH
I hope that's not the case. I have a rotary 3 speed still in the box that came with a standard 3 speed shifter.
One thing to note however is the rotary hub is low normal as opposed to the high normal of traditional Sturmey hubs.
EDIT: I just discovered I was mistaken about the low normal bit. I surmised that from playing with the hub without the rotary mechanism attached.
Checking further, I discovered that the spring return is housed in the rotary mechanism, and it is high normal when set up.
EDIT AGAIN: I just placed a call to UBS to enquire about the rotary shifter. It turns out it is indeed a dedicated shifter, and not interchangeable with the classic SA 3 speed.
Learning lots of stuff today.