I find it interesting that out of all the features and performance available on the T2, we only have one issue to focus on.

[Mike Hillis]

That issue isn't about depth. It isn't about sensitivity to small targets or conductors. It isn't about recovery time or iron masking or construction. The one issue we focus on is about one target. Steel bottle caps.

Here is a good link to steel bottle cap construction from the Coinstrike Homepage: Even though the CoinStrike is the machine being referenced, the bottle cap information is relevant to all machines.

http://home.insightbb.com/~johnhetti/coinstrike/bottlecaps.htm

The T2 likes to read steel bottle caps up into the high coin range. Not all of them but enough that we focus on them. Most machines show these as zinc range targets with the occasional one that hits high coin. Why does it like to do this?

Per Dave Johnson
"The things we did in the T2 to achieve its excellent target separation, deep and repeatable target ID, and quickness of response, also conspire to make bottle caps look like coins. "Third derivative discriminators" such as are found on a couple Fisher models tend to exhibit somewhat this same combination of strengths and weakness. A rule of thumb on rejection of flat iron is that the broader a footprint you use to look at it, or the more you smear its response, the easier it is to reject it. Unfortunately these same things compromise nonferrous discrimination and ID."

Now that this target has been focused upon, we have learned of several ways to correctly id this target.

1. In maximum discrimination, the T2 causes the audio to click on the steel bottle cap.

2. The FE3O4 bargraph spikes over the steel bottle cap.

3. The pinpoint mode gives a broader response over the steel bottle cap vs a coin.

4. Taking a moment to center and bob the coil over steel bottle caps will cause the TID number to fall further than a coin will.

5. The Discrimination 3b Audio Mode is designed to cause the steel bottle caps to give a more bouncing TID number than a coin.

Per Dave Johnson
"In the regular 3 mode steel bottle caps will usually give a one-way response if they're tilted, but if they're laying flat they can hit solid and consistent every pass, the way a coin does. What the 3b mode does, is to make them bounce around a lot more even when they're lying nearly flat. A coin will usually act the same in 3 or 3b. If you search with "# OF TONES" selected in the menu, when you locate a questionable target you can use the knob to toggle back and forth between 3 and 3b to see the difference."

6. Tilted Steel bottle caps will give a lower TID number or tone response on a 90 degree turn. If you do the X pattern walking in a circle around a coin, you'll usually get nearly the same response all the way around. In the case of a steel bottle cap, if it's tilted, you'll tend to get one-way high tone responses in two quadrants of the circle, and medium and/or low tones in the other two quadrants.

As all of us current T2 owners and future T2 owners spend more time in the field with them using these methods, we will find the bottle cap discussion changing to favorite methods rather than "this is a problem"

One last generic comment on steel bottle caps. In new areas we like to cherry pick through them. In old areas we dig them because of masking.

Happy

Mike

 

[Mike Hillis]

Dave sent this in response to the bobbing method for iding bottle caps that Id'd as high coins.

________________________________________________________________

Mike,

In mineralized ground, if you pump up and down for ID, it will tend to drop the ID reading esp. on deeper objects, so the method you propose will work on shallow targets in some areas, but not in heavier mineralization. The Fe2o3 method wasn't designed to aid in identifying targets but I'm pleased to see it helps in some situations.

The things we did in the T2 to achieve its excellent target separation, deep and repeatable target ID, and quickness of response, also conspire to make bottlecaps look like coins. "Third derivative discriminators" such as are found on a couple Fisher models tend to exhibit somewhat this same combination of strengths and weakness. A rule of thumb on rejection of flat iron is that the broader a footprint you use to look at it, or the more you smear its response, the easier it is to reject it. Unfortunately these same things compromise nonferrous discrimination and ID.

Dr. Johnson's quackery has been kicking in big time the last few weeks, and last weekend I hiked several miles in the local mountains without any subsequent neurological collapse. (If you know anyone who has Lou Gehrig's Disease "ALS", please encourage them to contact me.) So I'll probably be getting out again to do field testing, and hope to get some ideas on how to improve the bottlecap rejection without sacrificing the responsiveness that makes the T2 so desirable.

--Dave J.

_________________________________________________________________


I reported that all targets dropped in id, but that bottle caps dropped far lower than coins. I just need field experience to verify how well this method will work and what are its limitation.

Mike

 

[Ralph Bryant]

Mike,

I kind of suspected that would be the case when I asked you in an earlier post if you had tried the coil-pump on actual bottlecaps in the ground, that the ground mineralization might play a role in how well it will work in relation to the strength of the ground. Sounds like Dave is thinking along the same lines.

What kind of Fe304 readings are you getting in the areas where the bottlecaps seem top be the worst ? I think of all the several coins I've dug with the T-2 to date in my own yard, local school, a small park and a church yard, I've only dug less than 2 or 3 rusty bottlecaps and maybe a half dozen screwcaps. The screwcaps were only because I am digging zincs too and they were "wide but suspicious" signals, but for the most part the steel bottlecaps haven't seemed to pose much of a problem here locally as of yet. Ground readings here on the Fe304 are ranging back and forth between .03 and .1, mostly sandy loam here in the valley. Maybe there is more to the ground matrix mineralization level and bottlecaps dilemma than we think.

Ralph

 

[pineapple]

Mike/Ralph, Would have to agree with all that Dave stated. I also agree with your post Mike summing up the focus to date. I think there is one thing though that needs to be made clear and that it is not so much bottle caps in general that are causing me problems since I really haven't seen many others yet saying they have experienced the same but more so RUSTED bottle caps. I have and can easily identify the bottle caps in general regardless of type (alum, zinc, iron, etc). It's ONLY the rusted ones that are really problematic. In regards to the depth of these I have more of a problem with them when they are 4-8in down. Those above the 4in mark are easily identified, it's them old buggers that are bothersome. Beleive it is just a matter of time and identifying the best setting to work at. I liked Daves response in his second paragraph, first sentence, it nails it on the head and I believe I just noted some of the same in my last post. Overall, the unit is thus far a keeper and I suspect the winning combo will show itself sooner than later.

There are other issues besides that of the bottle caps, and the one that sticks out is sensitivity/response time as they relate to working trashy areas or even in areas where there are numerous targets under the current coil that comes with the unit. I haven't really focused on that becuase I believe alot of that can easily be overcomed once a smaller coil is made available for this unit. I'd like to see a 4 or 5in coil made for it. The unit works extremely well as far as target separation goes so masking doesn't seem to be a problem. Keep in mind too that some of what I am focusing on my only be inherent to this area because of the soil conditions I am working in. I will be on the road for the most part later this month and most of next. The travel schedule I have will afford me a chance to try it out in other areas/states so I am excited and looking forward to that. Appreciate the post guys....as the cable guy alays says....GET-r-DONE!!

 

[Carlk56]

You can rationalize this all you want, but the bottom line is that you have a metal detector that is a high end unit, and the top of its line, that will not properly identify steel bottle caps. And this is something the original motion detector, the Red Baron, would discriminate. If a Garrett Ace 250 will identify a bottle cap, and do it for under $200, something is very wrong. And this is the only iron problem we have heard of-SO FAR.
Evidently the man that designed this "marvel" is in the metal detector witness protection program, because he is not to be found-or he is out with some ETs testing its bottle cap rejection on the Moon.
So continue with the spin and hype, and the T-2 will die a quiet ignominious death.
And if I am correct, the man hosting this forum on the T-2 is selling his-that's a ringing endorsement.

 

[Anonymous]

Dave, do you have a concentric loop staged for release, as they seem to handle bottle caps better?

 

[Carlk56]

So in other words, bobbing the coil affectes all targets, and it is just a gimmick thought up to distract people. Maybe someone should contact George Paine, as he works on a for hire basis. Else its back to the drawing board for another chip.

 

[Mr.Bill]

If you don

 

[Anonymous]

n/t

 

[Anonymous]

Do you know of the release date of a concentric coil? How does the T-2 compare with your Edge for depth, of a dime or quarter-in your ground?

 

[ohio fred]

regarding the ace 250 for a 200 dollar machine it get good depth here in ohio especially with the larger coil. It will pull a hot wheel at 10 to 11 inches in ground and penny at 9 or 10 inches in iron, hidden and separate it from the iron by sniffing it out.Ground readings using mxt from 70 to 85.Iam here because i like to read about any new detector and its performances. I really like full in depth reports about how it works in the field,depth, separation and if it good on jewelry and old coins,or if it works it high mineralized ground,the mxt does not work so great here, one beach i go to it will hardly work at all.The ace 250 will give any top of the line detector a run for its money so its good for everyone at a reasonable price.Yes there is better detector out there.That why i like to read the forums and like when people post results with photos.The t2 is new and sounds great i wish it had notch and more coils,but that easy to overlook if the results are great. Thanks and good hunting

 

[Anonymous]

You cannot notch out individual numbers?

 

[Cody]

Rejecting bottle caps can be accomplished by most any metal detector. Different machine will do this in a variety of ways. The DFX has bottle cap reject, the CoinStrike has an iron adjustments, and the Explorer does it with screens, but all do so at a loss of depth.

Steel bottle caps if completely rejected cost depth on coins. If set to reject bottle caps then there is less depth so the design engineers has to deal with this problem. As an example the DFX has bottle rejection, hot rock rejection, but the higher the setting for rejection the less depth and sensitivity to coins.

Unfortunately there is no detector that will detect rings and reject all pulltabs, detect all coins and reject bottle caps. This is for very sound technical reasons that have not been overcome by any manufacture. If the T-2 was set to reject them then as with the other detectors the user is not told that there is a loss of depth for that reason. We may slowly figure it out or we can read some of the excellent technical post on the Internet that explains this problem or think as you seem to that it is some kind of a design flaw.

Ralpy, has been interested in a T-2 and DFX. We have talked about doing some trading so he can try the DFX and I can try the T-2.

 

[Ralph Bryant]

You've obviously been out of touch for awhile. Have you even "READ" anything posted here ? Give me a friggin break. As far as I know, I'm the only one who has even mentioned selling or trading a T-2, and ONLY for purposes of trying a different machine. Well, guess what ? I've also bought and traded many Nautilus units, Whites, Fisher, Tesoro, Troy, Minelabs, and most all top-of-the-line machines on the market at one time or another. Does that make them "junk" ? Not hardly ! The T-2 is an excellent machine, and personally I haven't had any "problems" with bottlecaps or anything else with it. I've said several times it is a "keeper" in the sense it is a good machine and very worthy of consideration, not that I am going to chain it to my leg for eternity.

It's funny that anytime some new competition comes along for the big dogs of the industry, they get all of their little minions out and running around biting at the ankles of the new guy on the block, bashing and trashing and doing their best to downplay another machine that doesn't eminate from the head of the red carpet, so gracefully bestowed upon the detecting public as the next "best" machine ever developed by mankind.

And NO I don't host this forum. I'm just another participant with an enthusiasm for a great new machine, with still others waiting in the wings to try. The T-2 is no slouch by any means, and will hold it's own against the best of them. I test drive alot of high-end cars at times too, but I don't necessarily feel the need to own one of everything.

Ralph

 

[ohio fred]

with the ace 250 you can notch out certain items with the mxt you can notch out certain numbers but is a dial up and you lose everything behind that point were as 250 you can use full open or pick what you don't want to hunt,250 is 200 dollar machine mxt around 600 dollars more features like threshold ground lock and some other and is a good machine but really doesn't work great in this area but will surprise you at times.T2 doesn't have notch but if it can hunt and go deep and find great items then it might be machine for me.Like to see some beach reports. thanks

 

[Scott Maine]

n/t

 

[Ralph Bryant]

There are certain aspects of VID machines that ALWAYS cause problems or concerns. A couple that come to mind are notching features affecting other non-discriminated segments and auto-track ground balance that always but always tends to track into fringe depth, small, or very weak target signals. BOTH have been eliminated from the T-2 design for the simple reason that they are a limiting distraction to a design that focuses on raw power moreso than bells and whistles. If certain features cause more problems than benefits, lop 'em off at the joint and focus on what increases performance rather than on what limits it.

The T-2 is a very high-gain capable detector design. As such, there are bound to be problems with some certain types of targets at one point or another. No machine I am aware of has ever been 100% accurate or capable of fully discriminating all rusty bottle caps, iron or steel washers, old iron tack rings, and the like. And the higher the gain capabilities of a machine, the worse the problem is likely to be. No machine is "perfect", but we tend to expect perfection in every new entry into the market, with some wise-ass badmouthing it or complaining because it does something it should be expected to do when the design and capabilities are considered. Of course a machine can be made to better discriminate bottle caps.....just turn down the gain and "tame it" into a passive just-like-everything-else-on-the-market machine with limited depth ability or poor performance in certain other aspects.

There are ALWAYS going to be trade-offs to be made when you reach for the upper limits of machine performance. But all of this tat about the bottlecap "problem" really needs to be put into perspective. There are some pretty experienced guys with these machines in hand, and this one relatively minor issue is the ONLY thing they can find to talk about ????? I suppose there are men out there who would complain about the mole on Cindy Crawford's face too, but most of us could probably get past that "issue" for the sake of enjoying the rest of the picture.

Ralph

 

[Anonymous]

Does BC reject improve dramatically if sens. is lowered. I know running my TBaron with full boost on the deephunter causes falsing at times, but generally the id bounces all over the place-and I know what is happening.

 

[Carlk56]

Now you are spinning-and trying to mix apples and oranges. Rings and tabs is a completely diffident situation than a piece of ferrous trash, that erronously reads as a quarter. The difference between the two is almost too extreme to contemplate. I cannot think of what else it can be termed except design flaw-because it was obviously designed with the acceptance of a bottle cap as reading a quarter as acceptable. If it was doing the opposite and reading quarters as bottle cap range that would be unacceptable to the end users. I suspect they went with this version because they figured they could update down the road. And simply wanted in the meantime to have it on the market regardless of the consequences.
Putting it out at Christmas was apt, because it is certainly a turkey.

 

[Ralph Bryant]

....that you have not even had a T-2 in your hands ? Yet you know enough about it to pass judgement based on what is amounting to a very minor issue for TWO users in THEIR ground conditions ? Thank GOD you're not a real judge, walking out of chambers and yelling "GUILTY" before the trial even starts.

Which manufacturer are you here to represent ? This is starting to sound like "Red Carpet" tactics employed whenever they start to feel even the least bit threatened or "vindictive".

Nuff Sed

Ralph