that's really unusual that they aren't gobbling at all.... what i normally do is wait to hear a bird gobble on the roost or right after fly down to call. if i don't here anything generally i do a very soft tree call(soft 3 syllable yelp) to try and get one. it's kind of boring in my opinion to hunt them when they aren't gobbling.... that is until you actually see a bird. you may try moving into an area further from where everyone else is hunting. maybe you can find a bird that hasn't been called to death.

it sounds like you have the right idea about not calling very much. that's the biggest problem i see people having when they first start out.