Caution with Disc

[christian_99]

Appreciate your comments to my earlier posts and I decided to do some field testing today, actually in doors with some of my square iron nail collection and some "cuff" buttons the size of a half dime, some with gold, others without.

The settings were sens 60, disc variable at from 10 to 30, and first the 2+, 3, 4, and finally the Dp mode.

With one square nail and cuff in one hand, the machine will mask out the cuff at about five inches in the higher disc setting. So for those of you who relic hunt you may need to see where the iron nail is eliminated and where the desired object is still read.

The Dp mode did the best at providing a moderately clean signal with disc at 25, again in the Dp mode. If you set the machine to the 2+, there is a fine line where the machine will eliminate both the desired object as well as the iron nail. So as a suggestion- work with these settings until you can eliminate or discern the desired object from near or close to an iron nail.

If you are at 40 you will lose most cuff buttons as well as the iron nail. So between 10 to 30/25 will probably work best. With sensitivity increased, the sounds for ALL objects sound better so the iron does more masking...and in some cases the cuff button was eliminated. Still working on settings that will eliminate the iron and hit the more prized relics to a cleaner note. Am interested to know if others have conducted similar experiments and what your findings were... So far the machine is starting to make more sense and hopefully it will provide me with more (cents)/relics out in the field.

 

[nymohawk]

It's a great way to get understanding, most detectors vary a lot. And knowing your detector is important. I'll just bet your finds will increase because your willing to learn what's happening bro!

Keep up the good work and share any ideas you have so that we can learn from the experiences you share!

NYMohawk

 

[jeff@middlesex]

I think dp offers the best chance of seperation, but thats only my findings.What is the square nail your using? dug? rusted? and how long?

 

[christian_99]

Well, the square nails(s) are from old hut sites and house sites that I have picked up through the past couple of years. They actually come in very handy for testing machines...some are large/ some small. Some have the traces of hot temps when the soldiers would burn the huts down prior to leaving. Just a mix of them, again useful for testing.

 

[christian_99]

No problem, the key to any...YES...any machine is how well it will work in iron. If you can eliminate the iron and find signals then that is the key. The question is with this machine, finding and using those settings which will accomplish this and well. I am looking forward to Gary's field test of the unit. So far all of the field tests from other sources have give this machine two thumbs up for responsiveness in iron. Needless to say, when I posted an earlier post about this machine I was a bit concerned when I went into a camp site that has been pounded by other machines and is littered with iron nails, and bits of iron every few inches, it is easy to walk over buttons, bullets, and in fact buckles in this environment. That is why I am wondering where some of the die-hard diggers are that had posted such tremendous finds earlier with minimal disc settings and high sensitivity. In the area which I described, the machine read the iron very well, but it also mis-read the iron and signaled mid to high tones as well. I investigated these signals and after six or seven holes, decided to investigate signals with the Tesoro Vaquero. So again, still learning....

 

[Jackpine Savage]

If I based a detectors iron handling and ability to signal on co-located targets on this type of test I would have eliminated some very good detectors. I'm not a tech but I know enough to realize that the newer detectors are designed so that they do their best at ID'ing and handling ferrous responses when the ground signal is also present and not all of the newer so called digital detectors are equal. Some are better (I could say deeper here) in wet conductive low mineral ground and some are better at iron ID and seeing iron co-located targets in damp moderately mineralized ground. Coil type can and does come into play regardless of the grounds "state" more than most realize also (caution: this is opinion only and not based on technical merit). Using a variety of detectors over time at a variety of sites is the only way to determine their overal capabilities as compared to each other. If only I could afford to keep em all.

Tom

 

[christian_99]

Tom, well put and very true! Appreciate your thoughts...what do you normally run the T2 in at contaminated "Iron" sites. Thanks!

 

[Jackpine Savage]

HI Christian, I do not have a T2 (yet)! I do look forward to what users think of the F-75 when it gets into their hands. Perhaps the changes in the process modes will prove useful to those of us that have preferred the CZ's and Explorers in the past when after co-located high conductive US coins. DJ would not give me any details on what changes are being made with the F-75 but has received a lot of input from the forums and emails he has received.

Tom

 

[mtdoramike]

n/t

 

[Jackpine Savage]

HI Mike, If I was loaded I would not have sold off most of my gold and jewelry this year. However, it was a good time to sell. <p>I took big hit back in 2000 and will be working til I drop.

Tom

 

[jeff@middlesex]

Do you find burnt nails have a different profile or reading than ones that have just rusted over time?

 

[christian_99]

I was thinking like you but started reviewing the T2 forum and the decent finds people were making in the iron. I too have an Explorer XS and have done well with it, but again that IRON really masks out the signals. Only a few machines have been able to cut through the iron like "butter" and right now I am working on taking a dull blade (T2) and sharpening it to get it in to some of these sites and pull the good signals. (Lets hope it works!!!) Hope you are well!

I do have a favor to ask, once you get the new Fisher will you pm me with some of your observations? Thanks!

 

[christian_99]

Great question and actually the sounds for each of the nails is different due to the composition of the nails and the matrix of the iron. With the machine they would give any sound high pitched, medium, as well as "low" when swept. This didn't matter whether they were burned or not. So they are consistent in their ability to fool the machine. Again, I am working on finding those particular settings which will null out the square, hand "cut" nails, to hear the smaller cuff buttons. If you have two nails together and have a cuff button in between, will X machine or Y machine pick up the cuff button and blank out the nails? That is the true test...and one that has to be examined. If you (since you own many machines) can use regular nails and find a lower conductor say a cuff button or similar item and see which one will signal on the lower conductor and null out the nails, I would appreciate it.

The T2 does remind me of a machine that I used many years ago in the mid eighties, the big bud pro. That machine was probably the best machine that I had ever used to date. Granted I have grown in my detecting skills by leaps and bounds- but the Big Bud, pulled a CSA button out of a trash pit at at least a foot in the ground in a pounded out site. The signal was repeatable and kept me thinking that it was falsing but I dug, and dug, and dug. Finally after 5 to 10 minutes of digging- I pulled the target out and low and behold the golden brown color of patina with the letters CSA appeared. Whew...what a day! So hopefully this machine will replicate that experience and then some!!!

 

[Jackpine Savage]

Well, it is hard to know what fits ones needs by reading others posts. I wish we all had a common baseline for discussing performance. What is heavy iron to one may not equal what others consider the same. Size, type and age of iron play also. I do not have to deal with square nails here in the northern lower peninusla. My sites are not that old but you have to deal with them every day so my thoughts and findings may not agree with yours on a given detector. In parks and other gathering areas older coins in my ground generally run 6"-8" deep and the iron is down in there at the same or deeper levels. In the woods 100 year old coins are only a couple inches deep here. Field hunting in the UK is different than here in the US as well. They roll fields and leave pasture alone for years. My old corn field sites are plowed yearly and left rough with only minimum discing when reseeded.

Tom

 

[jeff@middlesex]

Well I did a quick test in the basement as it is pouring rain here at the moment. Found a clear spot to GB and it came in at 66.
So sens at 60 in both 2+ and dp mode I can get the square nail to just churp a bit at a low tone with a disc setting at 19. I have a small button I used and it read that no problem with a locked on tone and VDI number. Chrisitian I think you need to set the machine not to eliminate the nails but to have them churp like mine or breakup only. I would not take the chance of setting a machine to null nails completely as this makes the disc window to wide and you will miss the small stuff or even larger targets that are masked. I had to keep the coil 4-5" above the target to get the machine to read properly as it was not a buried target with no halo or ground effect. As I mentioned before I hunt farm fields and I never dig square nails. I hear them with my settings, mind you not enough to drive me crazy. But I can here some of them when the coil passes over them, but not many.

 

[Captain Kirk]

I find the following in air testing in the dp mode using a 2" nail and dime separated by 3":

TARGETS LESS THAN ABOUT 6" FROM THE COIL
* When the nail passes over the center strip of the coil first, then I hear the nail tone first followed by the dime tone. The dime and nail tones are generally correct.
* When the dime passes over the center strip of the coil first, then I still hear two separate tones. The dime tone does not represent a dime (much lower pitch), but the nail tone is correct.

TARGETS GREATER THAN ABOUT 8" FROM THE COIL
* The T2 tends to generate only a single tone that represents the last target to pass over the coil.

Can you explain that?

HH,
Glenn

 

[jeff@middlesex]

I can see that with the coil above 8" as it needs the ground to do the job properly. Did you ground balance the machine first on all the tests??

 

[Captain Kirk]

I am not sure what ground balancing means in air as you can not pump the coil in Fast Grab. But if I set manual ground balance it does not seem to make much difference, but I did not spend much effort in this area.

Glenn

 

[MattR]

Glen.

Funny thing....here am I sitting at the computer keyboard, (Sat. eve. 2100hrs) pondering some replies about ground, mineralization and search-coil phase angle changes....all in relation to your e-mail queries,... and I click into The T2 forum for a break.

There you are, and your query is :-----

[size=medium]I am not sure what ground balancing means in air as you can not pump the coil in Fast Grab.[/size]

The answerer is 90. The default setting, that is, before any fiddling is done)............MattR.UK.

p.s.

Reading the subject thread is 'like old times'. (Been there, got the head-aches)

nail...coins....nail...spacing...on the floor etc.

Truth...? It is an 'illuminating' experiment, but not very realistic in practice.

Rusty targets such as pieces of iron, nails of varying length, diameter and degrees of corrosion. All are 'something more than' when laying in a 'infinite' 3D matrix of compressed ground.

Their orientation, 3 dimensional separation distance from a 'good' target. These are not reproducible nor represented by the simple tests being discussed. So the outcome of simple tests are very unreal.

I agree it is worthy of discussion, as long as it is understood that such conclusion are not very relevant to those you will experience in the field......MattR.UK

 

[Captain Kirk]

Matt,

I have in fact noticed that if you pull the Fast Grab trigger with the coil in the air you end up with a GP of 90.

The only thing really accomplished by air testing is give a frame of reference for what that is worth. I do believe that there is some level of correlation between air and the ground (which ground?). Unfortunately, I do not know what the correlation is!!

Glenn