VDI of coins vs soil conditions vs disc

[dixiedigger57]

a loaded question-- in my park zinc lincolns ring up as "screwcap" a lot- but not always. the dirt changes from clay mix to sand to powder soft black to wood chip lots. zincs ring up a lot of different numbers. now does the amount of disc and the soil condition have a great effect on the VDI? secondly does the closeness of the coil to the ground also affect this very much? i know when one is on top of ground or a big flatten screwcap it can overload and just raise the loop up, but that air between and i believe airtests for depth are different than actual buried. i know depth affects VDI on iffy targets. basically just curious on VDI and ground /soil conditions and accurate readings shallower targets.

anyone care to make my head hurt with some tech talk? lol

 

[Aarong81]

All areas will have mineralization in the ground so it has to phase that out with the ground balance. If it's properly ground balanced it should VDI pretty accurately with the exception of multiple targets under the coil(nulling or masking).

As far as Zinc pennies, they can VDI as low as +40's or perhaps even lower. They deteriorate in the ground very rapidly and only show up as Zinc when they are still fully intact. When they get the pits and the edges start coming apart they will show up much lower than expected. Bottlecap reading is not uncommon for Zincolns. Unfortunate, this same bottlecap/zinc signal is the same signal expected from Indian Head cents.

 

[dixiedigger57]

yea i noticed that an Indian head rings in lower than a wheatie... thats odd. with the urban beer drinkers here- screwcaps abound from certain favored brands that low income drinkers buy- and they are horrible to deal with. i dig them by the bucket- no choice and cant get around them. and they get buried deeper than you think somehow here. i guess in the summer the glass clippings and the heavy turf mowers push them in and the things just sink down. drives us crazy.

if they ever invent the machine that nulls on aluminum and sees past it-- disc knocks out too much good stuff--- dreaming again. hh carey