rifleman
The advice so far is Very good with my empathis on learning the language so as to get your sequence right and also to allow time for practicing with the howler.
I will not try to promote one brand over another. My own set came from the Late Bill Austin and my time of purchase was 1987.
Bet I listened to his tape a dozen times & practiced with the call for two months before ever taking it out and it payed off well.
Wont take you too long though. I was making inquiry howls & getting replys within the first week at several different locations and usually at night. Had to beat a hasty retreat one night in the off season with no gun when one piped up just 70yds away across the draw and up the hill. (didnt want to educate that yote)
My favorite phase has been to listen for that dominate male then heckle the dickins out of him with the challenge. Have had them come in from 2 miles away to check out this new intruder. I have challenged myself before when there are no replys. Usually allow some time to go by then get on the distress. The Coyote loves to see a fight and some will come in to see it.
There are alot of variations and you can offer something of attention to the male & female
My success rate with a howler averaged three coyotes within seven calling locations as compared to 1 predator in per every 10 calling locations with a squaller in those days.
I do not use the howler all the time or even in the same locations but rather try to change up on sounds and locations often to avoid educating them or burning out an area.
Your Purchase Will Be Worthwhile and great fun.