I've never used a crow, owl, woodpecker, etc. call in the fall. I always consider a kee kee, yelps or clucks as "locator calls" if I can't find a flock and scatter them.
They will certainly respond to those calls. I've had birds come in from very long distances and make their way over hills, etc. just to see who was "talking" to them.
As far as frequency of calling, I vary mine. I may just sit and call a couple of times, pretty low volume at first and not call for several minutes, just listening.
Those birds may hear you from quite a distance and even call back, without your being able to hear them, if you don't listen very closely. If I don't hear anything, I'll call pretty aggressively and then stay quiet so that I can listen. I'll repeat that until birds come or I decide to relocate.
"If he's out of range, it just means that he has another day and so do you."