Lowbatts,
The F70 is a very sensitive machine and I am still trying to get use to it and it is very site/soil condition sensitive. Here in Chicago I have just had it at some local Chicago Park District Parks. There is one park on the northwest side of Chicago I have taken it to three times. The place is very trashy. I turn the discrimination to about 55 on discrimination and the the only trash I pick up is aluminum twist tops which register at about 60 on the target identification number which is where zinc pennies also show up. Copper pennies show up from about 67 to 72, dimes about 72 to 78 and quarters about 79 to early 80s. In the 3 times I have went to this particular park I have found about 150 coins - all modern U.S. pennies, dimes and quarters except a 1917 and 1946 wheatie and oddly enough a canadian dollar coin Deepest coin has been about 7.5 inches. I have not tried to notch nickels back yet as shown in the video. Using these settings, I rarely dig any trash since I have given up on zinc pennies since half the ones I have found are too chewed up and corroded. When I hunt this site I rarely dig anything below a target ID of 63. Not going to find any gold rings on these settings but I was focused on finding silver coins which has still eluded me at this site.
I originally grew up 20 miles south of Stockton in a town called Mt. Carroll. The area you will be looking in was settled in the 1840s/1850s so there are plenty of old coins around. When I was a kid in the late 1970s to early 1980s I found most coin types going back to the 1850s in the places I hunted with a simple one knob Compass metal detector. Everything from a large cent to walking liberty halves. Somewhere around 1986 I lost interest in metal detecting as things like girls and cars became more interesting. Just getting back into the hobby.
