Uncle Willy
New member
This is to put to rest all the mysteries concerning large coils. As I have stated before, the size of the coil indicates the depth of the coil under ideal conditions on coin-sized objects, plus you will get a larger response to coins at ordinary depths. Whereas a standard coil may miss a coin on edge a large coil will catch it and emit a larger response even when dealing with ground trash.
A coin detected at 6-7 inches with a large coil will emit the same response as a standard coil on a coin at 1-4 inches. The advantage of the large coil is a signal cone that is larger at depth and covers much more area even at peak depth.
The disadvantage of large coils ( aside from weight when swinging for long periods ): The fact that they cover more ground and encompass more objects is bound to produce multiple signals at one time and when you have multiple targets ( such as five bottlecaps and one coin ) under the coil you can naturally expect multiple junk signals and rejections and miss the coin unless you can isolate the coin. But by lowering the sensitivity and raising the coil up a couple of inches when pinpointing, scanning real slow, and in side to side scans of just a couple of inches, you can isolate the targets and get around this problem.
There isn't much of an advantage hunting newer areas with a big honking coil and schools, parks, and similar sites built in the 1940's and 1950's will have coins shallow enough to be picked up with a standard coil. Where the large coil will shine is in the older areas from the 1800's to early 1900's or areas that have been landfilled or hit by a natural catastrophe that has moved a lot of dirt to an area.
Bill
A coin detected at 6-7 inches with a large coil will emit the same response as a standard coil on a coin at 1-4 inches. The advantage of the large coil is a signal cone that is larger at depth and covers much more area even at peak depth.
The disadvantage of large coils ( aside from weight when swinging for long periods ): The fact that they cover more ground and encompass more objects is bound to produce multiple signals at one time and when you have multiple targets ( such as five bottlecaps and one coin ) under the coil you can naturally expect multiple junk signals and rejections and miss the coin unless you can isolate the coin. But by lowering the sensitivity and raising the coil up a couple of inches when pinpointing, scanning real slow, and in side to side scans of just a couple of inches, you can isolate the targets and get around this problem.
There isn't much of an advantage hunting newer areas with a big honking coil and schools, parks, and similar sites built in the 1940's and 1950's will have coins shallow enough to be picked up with a standard coil. Where the large coil will shine is in the older areas from the 1800's to early 1900's or areas that have been landfilled or hit by a natural catastrophe that has moved a lot of dirt to an area.
Bill