I set up at the head of a large valley facing N, and started hand calling. Within seconds, a coyote pops around the hill to the NE of me, maybe 1,500yds out, and starts coming my way. I never made another sound, since she was on her way in.
She dropped down into the valley and I lost sight of her. Moments later, I could see ears, then the head, then the body, and she stops and stares at me from about 30yds, when I shot her.
From a distance of 1,500yds, with only my first sequence of calling, about 15-20 seconds worth, she knew exactly where I was calling from.
I use handcalls 95% of the time. I hunt some pressured public lands, and using a handcall sets me apart from the Foxpro-Luckyduck-Iotec users.
My thought is, on public lands, many new coyote hunters walk into the field, sit down and turn on the e-caller, without understanding things like the wind or how the lay of the land can influence the stand.
An example I use is calling in an open area, say a pasture, so you can see well, but there is a brushy creek bottom 150yds downwind of the stand. The guy might have called in 4 coyotes, but they all used the cover to get downwind, and the guy doesn't see a single coyote.
So, those 4 coyotes have all heard the exact same call associated with human scent. I suspect those coyotes will be a bit harder to call in again, using that same caller and sound. With a different e-caller, or a handcaller, those coyotes might respond better.