if one set-up doesn't produce, go another ravine over and do the same thing. don't stick to a regular calling regimen: switch it up and experiment. but the most important thing is after calling for about 45 minutes, give it at least another 45 minutes of silence, just waiting, because, especially in the early season when the elk aren't talking so much, the bulls are liable to come in from miles away without making a sound at all. you gotta allow time for them to close the distance, and allow for any hesitation on the part of the bulls. and if that spot doesn't work, keep looking. it takes time