Been doing some iron masking home tests

I have been keeping the rusted square nails from the site that I so often mention here. They are in various stages of decay. In my test, I dig a 5 inch deep hole. I lay three nails around the bottom of the hole (which is roughly 4 x4 inches) and then stick a few nails in the sides of the hole. I then replace the plug. I then swing with my Fisher F75SE with 5 inch coil. And then with my Garret AT Pro with 5x8 inch coil. I just want to hear what straight iron sounds like. I then lift the plug out and add a standing liberty quarter in the center of the bottom of the hole and replace plug. This is the best way that I can come close to imitating a natural condition. My Omega is on the Fed Ex truck for delivery today from Fisher Labs repair center and I will add it to the test soon. These tests are almost as fun as actually hunting. So far, IN MY SOIL, which is reddish in color and fairly mineralized, the AT Pro 5x8 coil with disc run up to 31 with iron audio ON has been the winner of the tests. I own both detectors and like them both and I am not the least bit biased to one or the other. I lean towards the F75 due to ergonomics and long battery life, but as far as testing like I have been doing.......you will be very surprised at how well the 5x8 DD coil from garrett is able to see the coin. Or bullet. I also remove the coin and replace with a 58 cal Minie bullet.
I will step away from the hole a few steps and then start naturally swinging to see if the audio will cause me to want to dig. The VDI of a standing liberty quarter surrounded by square nails was in the 30's!!!! Sometimes bouncing to the 40's.
I am going to do some more this afternoon as I wait on the Fed Ex driver and will snap a pic of my arrangement for any who are interested.
I would love to hear if anyone else has a test garden complete with square nails and how you arranged it. I think that much can be learned. I went back to the nail infested site yesterday and dug four more keeper relics. Two old condom tin lids (Koin-Pack) and two turn of the century buckles. Learning this stuff is fun.

Quick question...with the AT PRO, what audio tones are you hearing on the quarter test? Mid tone only, or mix of high and mid tones?

Nice report...keep them coming!

Thanks, Eric (NH)

Mid-tone and high tone as i circle the target. But when I make my first contact with target, as in: walking towards it swinging, usually a midtone with numbers in the midto upper 30's jumping into the 40's. So this changes the ballgame for me when I am hunting in nails!!!! It means this: I will be doing ALOT of digging. And relying on the depth meter to keep from digging surface foil and can slaw. But that's okay, I have accepted that there's just no way around it.

Kevin, very nice write-up. Very nice.

Steve

steveg Wrote:
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> Kevin, very nice write-up. Very nice.
>
> Steve


Thanks Steve. I enjoy doing this stuff. And I enjoy coming to this site and talking detectors. I REALLY NEED to learn something from these tests. And right nowI am at the stage of: I just want to know if there is a non-ferrous among the ferrous. The VDI numbers don't have to be accurate. But I can watch and see what they do when I get a non-ferrous signal, and then make a mental note of what the target actually is after digging it out. That is the best method. Real world testing. I need to learn to be a good notes-taker.

I just read this .... after responding to another.

Yes.......... this is going to be a major 'eye-opener' for you. ESPECIALLY when you transfer this data into the real world........ on a real hunt.......... in a nail infested area. This is where you will (by a large margin) have tremendous finds, tremendous learning-curve, tremendous confidence-building......... and sore muscles. After you learn this 'skill' you will run TO the iron infested sites............ instead of running away from these areas......................................... as has been common-practice in all our past detecting history. Do not down-play the AT Pro in these scenarios .... and do not downplay the F75 SE in these scenarios. You will find some 'differences' in these two platforms. Then........... the next question is................ can you find the 'niche' areas for both of these units.......... (independently from each other)............ due to their minute' differences.

""he VDI of a standing liberty quarter surrounded by square nails was in the 30's!!!! Sometimes bouncing to the 40's. "

Thanks for your post.
I've been very reluctant in taking my At Pro to the iron sites, but after reading your post I've changed my mine.
I am a 99% Etrac user and noticed on some of my good silver finds the iron number reaching down close to, but just above where a nail would read. I'll have to try the AT soon. Thanks again and keep us posted.

kevin,
is there any change if you stick the nails in the plug above the target instead of lying them under the target ? what if you lie the nails on top of the target also are any of the nails bent ? what happens when you use bent squres next to the target ?

again thanks for some good info as im leaning toward the at pro for a water machine keep up the good work !



Edited 1 time(s). Last edit at 02/27/2012 06:19PM by shilohdigger.

shilohdigger Wrote:
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> kevin,
> is there any change if you stick the nails in the
> plug above the target instead of lying them under
> the target ? what if you lie the nails on top of
> the target also are any of the nails bent ? what
> happens when you use bent squres next to the
> target ?
>
> again thanks for some good info as im leaning
> toward the at pro for a water machine keep up the
> good work !
Shiloh digger, the nails are never under the coin or bullet in my tests. I suspend the nails in the plug. In other words, I stick the nails in the plug. I also lay some at the bottom of the hole. And I do this in various configurations trying to create different real world scenarios as best as I can. There may not actually be as many nails in the real world scenario, but that's what I wanted. To create a real confidence in my machines. But if the nail is directly OVER the coin or bullet especially with a bitof space between them, it's goodbye bullet/coin. The units just wont see the good target.It's like Tom has said. That is where the limitations of technology exists. Or something to that effect.

thanks kevin awesome info and test you got going on i appreciate it

*** But if the nail is directly OVER the coin or bullet especially with a bitof space between them, it's goodbye bullet/coin. ***

You could think of an iron nail as a magnet that attracts magnetic field lines of force. Place the nail approximately horizontally in the soil and most of the nearby field lines orientate themselves lengthwise to the nail. The nail becomes the perfect deflector shield creating a field void beneath it. But if the positions are randomized I would hypothesize that a few nails (not too densely packed) could actually bend the field downward to enhance field depth of penetration. It's a complex situation for both the primary and secondary fields in an iron nail ridden soil matrix.

Kevin nice test. Today I found an 1893 IH with 2 square nails in same hole. Hunting in monotone disc0. walking into target I got a bouncy but solid signal,56 thru 61 on vdi as I turned 90 it started breaking up badly and vdi was anywhere 6 thru20's It would not pinpoint in same spot going from 90 to 90. Dug target, IH was only 3 inches but both nails were at least 2 to 3 inches behind IH back of plug and another inch deeper. the 75 gave me good enough info coming into target to dig evan though as I turned around targert it got worst. This happens a lot in nail/iron sites

Good observation........... good recovery. The more you repeat this.......... the more it is reinforced. Your hunting skills in the iron become tremendously better.

I can only guess that the absense of the halo effect in your garden will have an effect on real world hunting knowledge