OK more info...
I found a
stab website in Italy, they say that the 0 position is midpoint on the motor, so it mean "centered"... OK fine mine's not working that way.
I brought the 786NA box home and removed my Ultra and put it in its place, where I have an SM312D motor. It's been pesky in the past, but actually it's been working pretty good since spring.
Anyway, this motor moves just fine with the 786NA so I know it's not the box. There is either something wrong with the cable (unlikey) or there is something flakey with the
HH90...
Next step - bring both boxes back to the site where the HH90 is installed, drag them and some 110v power up to the roof and hook up right next to the motor.
For now, my experience with this Stab Motor is not-so-good. This is the 2nd one now I've had (1st one quit after 2 minutes on the roof, replaced under warrenty) and this one goes weird on me now after less than just a few months in use...
Will report back after the roof test.