Need help with discrimination issue.

[amustel]

Hello, everyone.
I have what I think may be a problem with my tek 4000. In the places I search I really don't care much for jewelry or nickels, so I use disc. in 80 (supposed to be dimes, quarters and up).

Now, I know that sometimes flat cans, large washers, bottlecaps, etc, may give a confusing high signal, but, with disc in 80, I get good, like coin signals for every piece of scrap, aluminum and more, not precisely large (by instance, I got a quarter signal with 86 VDI for a piece of aluminum that was about 1"x1". Although I am not an expert, I've own several other detectors, and I can't recall this happening with those other brands.

I wanted to ask you if this behavior is normal, or if you believe that my machine is bad or needs factory adjustment.

And second, in your opinion...what is the machine that, if you want only high vdi's, discriminates better iron, foil and aluminum? (and of course, gold... )

Thanks!

 

[Elton]

No machine will get gold unless you dig a lot of the same Signal trash Items Pulltabs ..etc..

 

[amustel]

Hi, Elton, thanks...but my question was not about finding gold.

What I need to know is what machine is better rejecting aluminum.

 

[Elton]

Not many current market detectors if any can take out Aluminim other than the thin foil type. Pieces will almost always hit on all detectors in the high range.
Etracs can take out some Aluminum pop tops ( screw caps) but even the TRAC can't take them all out.. The SOV with it's dial in notch works to a degree..

You will have to learn to listen a bit better for a higher sound on Aluminum.. Also you can raise the coil up and if at 4 5 6 inches your still getting a hit..Aluminum can be the culprit..Coins will drop off usually at 2" or 3" after raising the coil.. Aluminum cans will hit with the coil raised 12" above the ground.. Hope this helps you a little..

 

[Monte]

I have what I think may be a problem with my tek 4000.

No, not a "problem" per se, but a a particular quirk that needs to be understood, learned, and then dealt with.

In the places I search I really don't care much for jewelry or nickels, so I use disc. in 80 (supposed to be dimes, quarters and up).

While I don't fall in that crowd, I know of several hobbyists who just don't like 'JUNK' and they will run with a high Discriminate setting when they get into any moderate to heavily littered site. Most actually realize they are going to be missing virtually all common gold jewelry, but to them, dot digging trash is worth it. So, you are not alone.

Now, I know that sometimes flat cans, large washers, bottlecaps, etc, may give a confusing high signal, but, with disc in 80, I get good, like coin signals for every piece of scrap, aluminum and more, not precisely large (by instance, I got a quarter signal with 86 VDI for a piece of aluminum that was about 1"x1". Although I am not an expert, I've own several other detectors, and I can't recall this happening with those other brands.

Well, you didn't mention which brands you're referring to, but I know that I will usually knock out iron and most foil, bottle caps,, screw caps, and similar conductive trash with something like a White's Classic ID or IDX Pro and there are a few other that will also do this. No, not 100%, but darn near. I'm presently hunting with an Omega 8000 and have a buring urge to pick up a Gamma 6000 and T2. There are reasons why I choose these, and the main one being they have Ground Grab (auto-balance) and/or manual Ground Balance adjustment, and I prefer to have more control over a detector.

I know that mower-chopped aluminum cans can read higher in the VDI scale, as well as aluminum cans and such. Bottle caps can also be annoying, but a little operator technique will take care of most of them that are reasonably shallow (3"-4" or less). I do get bothers at times with some foil that reads high if it is in very close proximity to the coil, often reporting a '99' if the search coil is rather close. It's easy to qualify this type of trash, however, by raising the search coil maybe only 1"-3" and you'll hear the audio response weaken and the VDI numbers generally drop into the 30's and 40's and get very jumpy.

I wanted to ask you if this behavior is normal, or if you believe that my machine is bad or needs factory adjustment.

I think it is normal for these models to act that way. I've found that with the wonderful benefits that come our was with mode digital designs, such as light weight and reasonably consistent performance, there are some trade-offs that we just have to master and learn to deal with.

And second, in your opinion...what is the machine that, if you want only high vdi's, discriminates better iron, foil and aluminum? (and of course, gold... )

I know this is a Forum, but there is no such thing as a perfect detector. This is why I am a strong promoter of owning more than one coil and more than one model in order to have versatility for an assortment of tasks.

For example, if I am ONLY going to go after higher-conductive targets and if I MAINLY want to seek out higher-conductive SILVER coins in old-use parks and such, I am probably going to grab a Minelab Safari or Explorer SE/SE Pro and use their 11" Pro DD coil and work slowly and methodically and pay close attention to the audio and visual response as well as the depth gauge and try to limit my recoveries to those targets that are probably over 3" or maybe 4" deep. Only a half-filled or less "depth gauge." I know, however, that most Indian Head cents will "read" similar to the modern Zinc Cent and even sometimes lowers into the upper Screw Cap range.

Thus, if I want older, high-conductive coins, such as silver dimes and quarters and Indian head cents and 'wheat-backs,' I am going to be digging everything from (and including) Zinc cent or maybe just a little lower on up.

If, however, I have limited time to hunt and/or I just want to minimize recoveries and concentrate on higher-conductive targets that could be silver, AND I am hunting a trashier site or one with a lot of renovation debris, then I would grab a Teknetics T2 or Omega 8000 or Gamma 6000 with the appropriate 5" DD coil. Ghost towns, homesteads, sidewalk and/or street renovation and repair, most any dated site that is trashy, dug up parking strips, etc., etc., etc., would make a better place for a T2 or Omega or other "Greek" model especially with a small 5" coil. Their quick response and recovery makes them a dream to use with a 5" coil in nasty trash!

I also grab the Omega on days like today when I decided to hit some wood-chip playgrounds on the way to see my dear old Mother. Stock coil, Sensitivity as high as possible, Discrimination usually at #1, but if there's too much annoying iron 'hits' I increase it to

 

[Old Katz]

MONTE
What is "ground Grab" and how is this difference from regular
"ground balancing?"
Katz

 

[Monte]

simply an "auto-balance" function. You press-and-hold the Ground Grab touch-pad or push-button and bob the coil briskly from about 6'-8" down to about