coinshooting

SO YOU THINK YOU GOT IT ALL

In the last issue we checked out pattern searching and how you can miss a slug of coins and goodies even though you think you are thoroughly covering an area, and how you can improve your scanning methods to cut the odds down.

In this issue I’m going to make you feel even worse and show you what you are missing at peak of depth where the signal from your coil has coned and is only covering an area about the size of a dime or smaller. So take the number of potential targets missed that we discussed in the last issue and double or triple it at peak of depth for your coil. Gets scary don’t it?

How many times have you ( in your mind ) figured you had covered an area thoroughly only to have another guy waltz in and recover a choice find or two right where you had detected. Makes you mad enough to spit don’t it? I have had this done to me and done it to others and even pulled coins from their filled-in holes.
Does all this happen because another coinshooter has some exotic machine or is light years ahead of you in expertise? Neither of these may apply and it may just be your scanning style that results in you leaving a dozen coins behind for everyone else to find. Add to this the fact that no matter how sophisticated or exotic a detector is claimed to be it is still subject to the basic laws of electronics, physics, and nature. To cite an example ( figure # 1 ) of how easy it is to skip over coins at depth I’ll use my own experience. At a local park I picked up a weak signal and digging down about seven inches I recovered a Buffalo nickel laying flat in the hole. Checking the hole again I got some “ cracks” and “pops” for a signal. Checking, I dug into the side of the hole and out popped an 1899 Liberty Head nickel. Poking around some more brought forth a 1940 Washington quarter. Three wheat cents later I had exhausted this hole. How could this happen? Why didn’t the quarter which was the larger coin sound off first? The answer: The nickel was laying flat in the hole slightly above the other coins, which made it the primary target and all the other coins secondary targets. The detector’s signal will choose the first target it encounters and lock onto it, no matter how many other coins are below it or around it. They all become invisible until the primary target is removed, and the signal will accept a flat coin over one on edge every time as the signal reads surface area, not mass or thickness. Even with a mass of coins, the top coin will read first and if a secondary coin is near the primary target but out of the signal cone it will be missed altogether. And this is why chains are so hard to detect at depth. Depending on how the chain is arranged in the ground your signal will only lock onto one or two links of the chain - not the entire chain.

To completely understand this scanning factor you must understand the manner in which your coil signal travels down into the ground.

In figure # 2 you can see why coins are missed as they fall out of the signal cone. The deeper the coin the less likely it will even get into the signal field. If your machine has a maximum depth of eight inches on a dime and you have two dimes several inches apart you had better have a very tight overlapping scan or you will miss one dime completely. And if you make your second pass, slightly overlapping the last pass, then at depth you have missed an area nearly the width of your coil. If you are using an eight-inch coil and overlap 50% of the last pass you will still miss a four-inch wide swath at peak of depth.
Say you are hunting a 10’ x 10’ area. How long would it take you to thoroughly scan it? Twenty minutes? An hour or more? If you said either you have a problem. If you said longer then you are most likely a coinshooter who finds coins in allegedly worked out areas.

To cover nearly every inch of area at depth of detection you would have to over lap each prior pass nearly the width of your coil and this would be virtually impossible to accomplish. So this is why you never get it all even though you are sure you did, and this is why no area is ever totally hunted out. No matter how thorough you deem yourself to be you are leaving a long trail of goodies behind and so is everyone else.

When someone tells me that an area is completely hunted out or that some new, exotic machine has found all the coins everyone else missed, I just smile and say, “ Sure they have.”

BGR