I have a preymaster but don't use it a whole lot I use hand calls more nowadays. But I use it on occasion, when I used it alot I had the best luck with the yellowhammer woodpecker , coyote pup distress , and high pitched cottontail and yellowhammer played together . Its an awefull sound but the coyotes liked it. I have called bobcats very effectively with the housecat distress mainly around the breeding season. The amount and volumn that you use is IMHO far more important than the actual sound. There can be too much of a good thing, my sequence was generally like this: Low vol. 3-4 cycles wait 5-10 min.
med vol. 3-4 cycles wait 10 min.
A little low to med. vol. on a hand call in case a customer is on its way, wait 10min. Then let her rip for a few minutes , alot of times this is when I'd change to a different pitch and sequence. Allthough I try to stick with basically the same type critter sounds, just higher or lower . You'd be surprised how often just the pitch difference will result in a coyote trying to get in your lap at the end of a stand. I believe they hang up alot of times and are never seen in the thick stuff, but a little change will often be the trick to trigger them.
Good-Luck,
zapper
One more thing I forgot I had good luck using the coywolf barks /howls I would only do 1 or two howls and turn it off and wait 5-10 min. Then repeat , if no luck go into distress. One tip if they don't answer the howls that doesn't mean there not heading at ya" more often then not they wont answer, but they come.