In the past I've used mianly Primos' Diamond Yelper , and Diamond Cutter. I just switched this spring to a couple of Stevepa's calls . They are far superior on hen and gobbler calls .
As far as making the gobbles , well ,I'll try my best to describe it .
With no call in your mouth , pretend your blowing out the candles on a birthday cake. Blow out the imaginary candles a few times .I ask you to do this to get the feeling of the shape of your mouth and lips . Now using the tip of your tongue , as you blow out the candles , turn off and on the air flow . Next repeat the blowing , and the tip of your tongue action and HUM out the rhythm of a gobble . Lastly cup both hands in front of your mouth to get that HOLLOW sounding part of the gobble . Insert the call and try it .
I didn't think this all out for myself and grab my call and start gobbling either . I have been making perty good jake gobbles for several years . That is jakes of the first year . They do sound goofy and like someone on the forum said ''sounds more like a barking''. They are perty simple to imitate , in my opinion.
My real gobbles actually improved just this spring as I was practicing at work . I did some impromptue experimenting and it turned out far better than I expected .
I realize my steps of teaching are about as goofy as it can be but that's the best I can come up with .
Hope this helps .