Thanks for the info guys - looks like my 17B is working like it was intended but, for me, lifting the throttle out of its lock to reverse, etc. is a PITA.
I'm gonna replace it with a Lionel transformer again. The ZW was overkill for my loop, I'll probably use a LW.
Thanks for the catalog pic FlyerRich. For information purposes, the 17B looks just like the pic of the 19B but without the center toggle switch