So an iffy signal is one that is not spot-on, sounds a little good (generally more higher toned and smooth than not) but isn't a perfect "dig me" signal. Knowing iffy signals with your metal detector is being able to tell what's trash and what's just barely better than a trash signal. It's a finer tuning of using your machine and your brain.

The two Indian Heads and two Wheats I dug from one site are perfect examples. Suzanne and I both hit this area of the park hard. Multiple hunts, gridding, etc. But

They can be found, but are not easy to identify. I've located about five. All of mine have been in pocket spills with other coins. Sometimes there's enough detail to make our the bust of Lincoln or you can see the edges of the struck up rim, but not always.