Hey Doug.
Wow! Another Nebraskan. Good to see ya here.
About your Zinc troubles...I hear ya. I've got a park that has a number of them AND IH's...well, had a number of them. At this spot they can come in at the same number which also means the same sound. One trick I do and worked for me pretty good last time is to:
Lower the gain to about 15. By doing this one thing, I was able to pick up "volume" wise the deep (8-10") targets differently than the shallower (2-5").
Let me state by saying I do not always do this nor recommend it all the time. But at this particular spot I've found an IH or Wheat for that matter that was shallower then 6"...with about 30 hours at this area. Once you've dug a few targets at some spots, you get a feel for the how deep things are.
You probably know all that through experience with your SE. As far as the numbers go the MAJORITY of my IH's come in at 12-34, zincs usually ride that 12-38...but again, I've seen it reversed as well.
NebTrac