Re: what call and when for spring turkey
You need four calls to really be successful at calling and locating turkeys.
A box yelper is essential for locating at distance. A good slate is a must too as they are extremely versatile to getting them closer. For dark/dusk have an owl and a crow call to get them gobbling in the tree.
I've gotten a big tom every year since 1995 and here is the best advice I can give you: Put them to bed and wake them up. Find the flock in the evening, follow them until they roost so you know what tree they are in. Be back to the tree at first light and set up around 50 yards away. Call every few minutes and the first they do will be to come to you.
During the heat of the day they rarely gobble but you can get a bored tom to wander in. It's boring and you don't know of it's working, but it does work.