Can this adjuster be used with awning windows?

I believe the 39-077 window adjuster could work for an awning window. The weight of the sash might cause the bar to slip, so after you push open the window to the correct opening you need to tighten down the brass set screw.

It's entirely possible that the 39-077 can work on awning windows, but it would depend on the size. Figure that the arm on this operator is only 12-1/4" long. That's not a lot of space to work with, and awning windows tend to require larger mechanisms. You also have to figure that it's not made to work in that capacity, so at the end of the day it's not a guarantee even if the size is right.