Nails in the Side of a Hole

Having spent quite a bit of time using my F75 LTD I would like to hear from anyone that has encountered the following. On several occasions now I have dug an iffy signal that, after getting the first plug of earth out, turns into a sweet 4 way high tone. Sometimes I find a good target. But several times now, after digging quite far down with the sweet 4 way tone continuing to register after each dig, I find nothing, at least in the bottom of the hole. Determined to find out what is going on I use my pinpointer to check the hole and many times I find a rusty nail or piece of nail in the side of the hole at some level. Why does a nail in the side of the hole result in a nice 4 way high tone? This is just not a one time thing. I've seen it many times now. The other odd thing is that when I pinpoint in these situations, the loudest pinpoint location is over the center of the hole, not off to the side. I know this is caused by the nail because when I remove the nail, and then sweep back over the hole, the high tone is gone. Seen this many times now and would like an explanation if there is one. Thanks for replies.

That's odd, as I've found the LTD to do exceptionally well for in iron for the most part. Unless I'm digging the really iffy, fringe, crappy sounding targets, more often then not when I find iron in the hole, there's also a good target in it.

What settings are you running?

Yes dgc, It happens to me at least once or twice an outing. Most of the time it's a large nail (3" +) or a piece of iron of similar shape in the side of the hole and deep. Also if it's a large piece of flat iron I'll get a good 4 way high tone. The f-75 says it's mid or shallow in debth. After digging past what the machine says, I know it is going to be a piece of iron, and dig it out of curiosity, it's usually deep (12"+). Sometimes the VDI will bounce one sweep high, back sweep low ( VDI 2+- to 85+-) I don't dig those unless I sense a collocated non-ferrous target, and thats usually a flash of more than one reading in one sweep. I come across these situations mostly in farmed land (or once farmed) from plow parts to tractor pieces & who knows what.
Some detectorists can read the tones and tell without digging. I'm not sure there is a way around this for me because my hearing sense is a bit impaired from my life style. So I'll dig and keep learning and re-learning untill maybe I'll get it right, or not. Either way I still find the good stuff and am satisfied.

Steve

Cal_cobra Wrote:
-------------------------------------------------------

> What settings are you running?


Not too hot. Disc 4, Sens 60, bP mode, 4 tones. The amazing thing is how sweet the high tone is with a nail in the side of the hole. Not broken at all . Absolutely perfect. You'd swear its a good target. Yet once I dig the nail out of the side of the hole, the signal disappears completely. And, as I said, I've seen this situation many times now. Definitely not some anomaly.

I was thinking about why the pinpoint center is right over the center of the hole. Maybe because, by digging the hole, I've created an air gap to the nail. In other words, there is much less earth between the coil and the nail out over the center of the hole than there is straight down to the nail over the side of the hole. Stronger signal through air than straight down through the undug earth over the side of the hole.

Thanks for your help.



Edited 2 time(s). Last edit at 05/07/2010 02:58PM by dgc.

ozzie Wrote:
-------------------------------------------------------
> Yes dgc, It happens to me at least once or twice
> an outing. Most of the time it's a large nail (3"
> +) or a piece of iron of similar shape in the side
> of the hole and deep.
> Steve

Thanks for replying Steve. Sometimes I end up finding the nail in the side of the hole only 2 or 3 inches from the top and I dug right past it thinking there was a good target straight down.

If the pinpoint seems to move once you dig a plug 9 out of 10 times its that nail on the side of the hole and just replace the plug and move on..

From reading posts and research I thought Fisher F series had improved this problem with new technology but apparently not..

Don't have a prayer why this happens but would imagine the nail leaches into the ground causing this effect.

Might want to try my method with the CZ on line one and of course other suggestions or opinions welcomed...for our F series detectorists but if you use a CZ using my method will certainly cut down on nails dug that come in high tone..

Dan-Pa. Wrote:
-------------------------------------------------------
> If the pinpoint seems to move once you dig a plug
> 9 out of 10 times its that nail on the side of the
> hole and just replace the plug and move on..


Thanks for the tip Dan. Maybe I would note a change in the pinpoint location if I'm careful to get an accurate pinpoint location before I start digging. I'm still curious about why some nails in the side of holes ring out with such sweet 4 way high tones.

I can say that when I hunted a 1840s area that had a town on the land back in the day and now it is all gone and has been for years and years. I found more of my best finds even a 1860 flat buckle in holes that had nails then finds that were all by themselves. I will have a video call ChinaTown I am working on that I will post in a couple of weeks. I had to dig any good hit one way two way four way. It was relics hunting through trash but it so paid off. My body was so tired I knew how hard the people had to work back in the day all labor but the finds were worth it.

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

[www.youtube.com]

If you don’t dig it, then how are you going to know what you’re missing!
How can you have your pudding if you don’t eat your meat!

My hunt would have been a bad hunt if Crosby and I had not switched and used our 5" DD. With that coil I was finding alot of old relics and there were so many chinese coins I started to stop uning my camera cause I was saying here is another coin and here is another and another.

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

[www.youtube.com]

If you don’t dig it, then how are you going to know what you’re missing!
How can you have your pudding if you don’t eat your meat!

Lawrenzo Wrote:
-------------------------------------------------------
> I will have a video call ChinaTown I
> am working on that I will post in a couple of
> weeks. I had to dig any good hit one way two way
> four way. It was relics hunting through trash but
> it so paid off.

Very much looking forward to your new video. I'm sure I will learn something and also just enjoy watching your digs. Thanks to all you folks who post videos. I know a lot of work goes into it.

Next time this occurs..........check your confidence bargraph AND change your Grnd Bal...... and see what happens. You will be surprised.

Also..........It is usually the tip (or the heel) of the nail that poses this problem you describe. If you were to look at the eddy currents generated when the source is exposed (transmitting coil).....you would see a double-donut figure-8 pattern along the longitudinal axis of the nail.......with the bulk of this double-donut figure-8 OVEREXTENDING/beyond the tip and heel of the nail. Yes, a displaced pinpoint.

Tom

Maybe it's my ADD but not following you on this comment can you expand plz

"AND change your Grnd Bal"

Change it how?

Let's say you acquire one of these 4-way hi-tone signals (which eventually turns out to be the tip of a nail pertruding out into the hole). If you performed a Grnd Bal at the beginning of your hunt....and the unit Grnd Bal'd to the dirt at...say; '65'................,,,,,,,,,,,,,,try manually adjusting the Grnd Bal to ....say..... '45'.......then say...'31'. Experiment with different manually set GB settings....and see how this 4-way high-tone false resolves.

Also............before you perform any of these tests........simply see what the Conf scale on the faceplate presents. Chances are.....you may receive a 4-way high-tone.......yet, the Confidence bargraph will be low (or zero). Another clue!

Thxs I'll give it a shot tomorrow. Hunting a school yard thats going to be excavated and remodeled starting Monday. It has a Confederate line and forts running right through it. send me some good karma. :>)

NASA-Tom Wrote:
-------------------------------------------------------
> Next time this occurs..........check your
> confidence bargraph AND change your Grnd Bal......
> and see what happens. You will be surprised.
>
> Also..........It is usually the tip (or the heel)
> of the nail that poses this problem you describe.
> If you were to look at the eddy currents generated
> when the source is exposed (transmitting
> coil).....you would see a double-donut figure-8
> pattern along the longitudinal axis of the
> nail.......with the bulk of this double-donut
> figure-8 OVEREXTENDING/beyond the tip and heel of
> the nail. Yes, a displaced pinpoint.
> Tom

Excellent explanation Tom. Never realized the electromagnetic field along the axis of a nail had that type of geometry! I'll have to say I've never looked at the confidence bar in this situation either. Next time I certainly will. You've really helped me on this one.

Also realizing that some of the concerns expressed about digging deep holes on a good signal from the F75 LTD and finding nothing may be related to this phenomenon. Before digging too deep, always check for nails first and save yourself some frustration.

Many thanks.



Edited 1 time(s). Last edit at 05/08/2010 07:04AM by dgc.

Start with the Conf bargraph first......(it's the easiest).........but only as a indicator.

Validated your advice today Tom. I got a signal that seemed to be a good one. After removing the plug I swept the hole and had a nice 4 way high tone. I looked at the Confidence bar graph and it only showed one bar. I then manually reduced GB to 40 and the 4 way started breaking up. At a GB of 10 it was not repeatable at all. I knew what was there at this point but went ahead and recovered it anyway. It was about 4 inches down in the side of the hole. I've got a method for identifying these now. Thanks again for your advice.

What would happen if it was a good target and you changed GB would the target still sound four ways or break up?

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

[www.youtube.com]

If you don’t dig it, then how are you going to know what you’re missing!
How can you have your pudding if you don’t eat your meat!

Nail tips, that makes sense. Usually you can determine if it's a nail when your pinpointing (it's long, not short and sweet like a coin), and by moving around it, the tone ID will be different, usually it'll break up (iron grunt) when the DD is parallel to the nail, but it'll sound good when perpendicular to the nail and it hits the tip. Some times you'll get a double blip when the coil is perpendicularly scanned over the nail, but not always.

Nice to see this mystery solved (or Myth Busted



Edited 1 time(s). Last edit at 05/09/2010 10:32AM by Cal_cobra.

Lawrenzo Wrote:
-------------------------------------------------------
> What would happen if it was a good target and you
> changed GB would the target still sound four ways
> or break up?


Good question. I'll try it on a test garden coin.

Hope you don't mind me stopping by too. Here is a small sample of iron I got this morning from a new site. I will be back to this site with the Dankowski/Magnate method for sure! >)
The iron was so bad I had to run wide open (no discrimintion) and eek out both wheats that were mixed among the iron. (2 holes out of 15 that had keeper targets)
If your detecting in iron rich grounds, take lot's of deep breaths and aim for anything non-ferrous. If you manage both of those things, your doing great!






Edited 1 time(s). Last edit at 05/09/2010 05:27PM by SilverPeter.

SilverPeter Wrote:
-------------------------------------------------------
> The iron was so bad I had to run wide open (no
> discrimintion) and eek out both wheats that were
> mixed among the iron. (2 holes out of 15 that had
> keeper targets)

Thanks for posting Peter.

Can you describe what the initial tones sounded like when you found the wheats amongst all that iron? I often wonder if I'm passing over some broken hits that I need to be investigating. I always get the high tone iron false chirps but occasionally I get a mid tone mixed in. Are the broken mid tones a more reliable indication of non-ferrous material co-located with iron?

HOW DID YOU POST YOOUR PHOTO

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

[www.youtube.com]

If you don’t dig it, then how are you going to know what you’re missing!
How can you have your pudding if you don’t eat your meat!

dgc Wrote:
> Can you describe what the initial tones sounded
> like when you found the wheats amongst all that
> iron?

Just like Tom's DVD, he runs 4 tones so he hear's 100% of the targets in the ground - "A 100% of the time".
Remember that second or third hole that had "scoops and scoops of nails" in it? He thought there
might have been a good tone amongst all the iron. He cleared a good portion of the nails and did manage
a non-ferrous target.
For me-It's a very slight seperation in noise that I listened for. Since the iron has a similar tone as silver,
it has taken me awhile to learn the difference. So in "all metal" mode, I just listen for a high but different tone.
And dig it! Sure-Most times I was wrong but twice, picked up a wheat penny and a clad Q on the third hole.

Very challenging!! But your on cloud nine when you find something in Iron rich ground. And I keep the volume
on the low side... Otherwise you will go crazy with that chatter/feedback that is in the soil.

Oh-The images I placed on Photobucket. Follow the prompts and there is a box next to your photo that
gives you options to place a embeded link here on the forum. The "code" can be copied from Photobucket then
pasted here in the main body of your post.

Lastly-If you don't have this DVD-Get It!! It is the cheapest 25.00 you will ever spend. And you will
Maximize your time in the field. Thanks!!

****Thanks Tom-In a wierd (ok-very wierd) way, I was glad to photograph the nails with my
keeper targets. As the "easy" grounds get hunted out, those who go for the tuffer locations will be the
ones who reap the most rewards. I get frustrated from time to time for sure, but if I sit back a
minute, and realize nobody else is here doing this, I feel fine and keep going.



Edited 1 time(s). Last edit at 05/12/2010 12:21AM by SilverPeter.

SilverPeter.......NICE photo. I had to comment on this one!

DGC......and all other folks; when you have a nice 4-way tone....and it is NOT a nail-false...or tip of a nail...........,,,,,,,,,,,,,what you will see is the Conf bargraph 'wanting' to give much higher readings..............and when you drop the Grnd Bal........a real coin will continue to survive as a high-tone for quite a bit more. You will see a very fast learning curve for this trick. Not much mental effort exerted.


NOW............all said-n-done; what if you have a coin AND a nail together??? All bets go out the window......and then the only thing you can rely on is audio ONLY! ..... and it will not sound very confident. This is the difficult/slow learning curve.......but to the best of my knowledge......only the T2/F75 platform will still give a 'ratty' incorrect ID...... but at least a non-ferrous ID; whereas all other units will simply just give you a 'iron' ID; which, in turn..........causes the operator to leave the so-called iron in the ground. If the non-ferrous target is TOO badly masked.....the T2/F75 will be totally/completely masked; end resultant: 'iron' ID. (More common then most would think).

Tom