My brother and I have been cussing and discussing this subject for many years. Like you, most of the finds we make in bean and corn fields are 5 inches or less. Occassionally I've dug deeper coins, but most of them are fairly shallow. In my opinion, part of the reason could be that the soil has been disturbed, possibly creating a "confusing" ground matrix to the detector. Secondly is that most of the fields have an uneven surface. This usually causes us to keep the coil an inch or so higher than usual to keep the coil from getting snagged up in the stubble.(even higher in corn stalks) And third, your sweep elevation is limited by the stubble or stalks left in each row. By that I mean you usually end up "dipping" the coil in the middle of the sweep and raising it at the ends. What I ended up doing last week, when I found that SL dime and those IH cents, was to lock in my ground balance manually and keep checking it every couple rows. I don't want tracking on when I can't keep a constant coil elevation. Next, I turned my sensitivity to the max and lowered the Threshold so it was just barely humming. (one setting lower than I usually hunt with) I also made a conscious effort to work each row in more of a diagonal pattern. Primarily because it allowed for me to make a longer sweep. But also because the coil would deflect off of the stalks more easily than hitting them dead-on.
I know you don't like to hunt in all metal with multiple tones, but I'm convinced that it is the deepest setup for this type of hunting. Having the higher sensitivity "compensates" for raising the coil over the stubble. Lowering the Threshold to a barely audible hum keeps the false signals at a minimum. (more of a problem when hitting corn ctalks than bean stubble) when you change direction at the edges of each row. All metal makes you more aware of where all the adjacent targets are located. And the multiple tones will allow you to "discriminate" with your ears instead of worrying about numbers on a display. Stopping to resweep a target that has been discriminated (nulled) out by a Pattern, or to look at the display, just interferes with a consistent overlapping "row hunt".
It would be interesting to have X-Ray vision just to see the depth of the coins in a field. They first land on top of the ground, when they're lost. The wind blows, the rains fall and they begin their descent into the earth. They are tilled under at varying depths, depending on the equipment used and where they "fall" in the furrow. In dry years, they fall into the cracks and simply disappear. And year after year after year, the formula becomes more complex. Frankly, I suspect some fields that have been plowed for generations probably have as many coins still hiding at depths of 8 inches as there are in the top 8 inches. And now that farmers are using minimum till techniques, we're likely to never find them. Some of the fields I hunt, I've been hunting (off and on) for the better part of 30 years. Not to sound arrogant, but I consider myself to be a pretty thorough coin shooter. When I go back to a field and find a handful of coins, I have mixed emotions. First, I am tickled to have found more coins in a spot that I thought I'd beat to death. Then I get wondering how I could have missed them so many times before. If they happen to be in line with the corn this year, they should have been in between the rows of beans last year. And if so, and I walked down the middle of the rows, how did I miss them? Did I get lazy and not overlap my swaths enough? Or did I just not hit that row? I know there are a lot of rows in an 80 acre field. (30 inch rows..... you can do the math). But to think of how many times I've been over the same sites, with a dozen or more detectors, and still come out with coins simply amazes me. Again, I'm not trying to sound like I'm bragging, but that seated dime I found in that field last week was the 20th seated dime I've taken from there. Besides the dozens of Indians, several two-cent pieces, a nickel 3-cent piece, quite a few shield nickels and a couple seated quarters. And that is just me. There are others who have hunted it. Like I said, on one hand it makes me frustrated. But on the other hand, it gives me a place to go back to next year. And the next year. And the next year. etc. etc. etc. My best advice is to keep the coil as close to the ground as possible, run with the Sensitivity set as high as tolerable, lower the Threshold to minimize the falsing caused by the higher Sensitivity and coil movement, constantly monitor your GB (but don't run tracking) and set up to hear the most information your detector can provide. And lastly, hope that the price of fuel goes down and they all start plowing again.
Just remember, you won't get them all this year. But you'll get more than the guys who don't understand hunting a rough 80 acre farm field is much different than hunting a city park. JMHO HH Randy
