Frank I have been sitting here watching all the replies to question. There is nothing wrong with your detector or you right at the moment. As the road of experience lengthens you will start to get it, and older silver coins and gold will start to show up. 30 hours isn't much time. I have 92 hunts on my F70 this summer. That is 92 days out in the field. I have gone through 5 sets of batteries @ 40 hours or more a set. That is something like 200 hours this summer. I really went through 6 sets of batteries but I can't count the last set because I left the detector on after hunt #91.
As far as finding silver coins. I have found silver coins in tot lots and schools playgrounds and on the beaches. My silver and gold are found by accident. I am out just coin hunting and having fun. Most of my coins are in the 1" to 5" range. My coins are Quarters @17%, Dimes @18%, Nickels @10% and pennies @55%. So you pick up a lot of pennies and also pick up a lot of trash. If you get tired trash just say to yourself boy this detector really works good there was a target there as it showed. Have fun and enjoy the hobby. Thanks for reading and Happy Trails....Z
As far as finding silver coins. I have found silver coins in tot lots and schools playgrounds and on the beaches. My silver and gold are found by accident. I am out just coin hunting and having fun. Most of my coins are in the 1" to 5" range. My coins are Quarters @17%, Dimes @18%, Nickels @10% and pennies @55%. So you pick up a lot of pennies and also pick up a lot of trash. If you get tired trash just say to yourself boy this detector really works good there was a target there as it showed. Have fun and enjoy the hobby. Thanks for reading and Happy Trails....Z