pi machines

[findit]

anyone use one on land other than the beach?

 

Amazon Forum Fav 👍

Agony and Death on a Gold Rush Steamer: The Disastrous Sinking of the Side-Wheeler Yankee Blade - Grab it through Amazon!

[bakergeol]

I use a GS5 for gold prospecting and on occasion coin hunting.

In the past PIs have mainly been used at the beach and for nugget hunting.
They offer superior depth and can be used in heavily mineralized soil. Mineralized
soil is common in gold producing areas and it is the preferred machine for serious
gold prospectors.

The more mineralization the greater advantage a PI has over a VLF. For example,
at a recent relic hunt White's new TDI completely blew away all vlfs in the hot soil
conditions at the hunt. VLFs just were not able to obtain the deep depths which a
PI is capable of in extreme mineralization.

The reason why PIs in the past were almost exclusively used at the beach and in
prospecting is the lack of effective iron discrimination. At the beach and gold prospecting
you simply dug everything. Without effective iron discrimination (and really deep depths)
one could not use a PI for coin hunting.

Well the secret is out now and the above paragraph is not correct. When Eric Foster built his
GS5 several years ago some of us found that it was a heck of a high conductor coin machine. With the proper settings one can ignore all iron (and pulltabs) and dig mainly high conductor coins. At the iron reject setting you will dig some al screwcaps and larger low conductors.

Eric Foster's design was incorporated into White's new TDI and the TDI has the GS5's capability for total iron reject for high conductor coin hunting.

Users of the GS5 and TDI have posted their results in finding new silver in "hunted out" parks which have been detected by hundreds of vlf users. This has of course created a lot of interest in Whites new TDI. In fact there is quite a waiting list for the machine as it has not been released yet.

It should be remembered that these are PIs and quite different from a VLF.

http://members5.boardhost.com/MetalDetecting/msg/1211955225.html
http://members5.boardhost.com/MetalDetecting/msg/1211622470.html

So now you know.
George

 

[U.K. Brian]

I've three of Eric's P.I.'s and I do use one on land at times.

George has mentioned the drawbacks and the fact is a GOOD V.L.F. can be as deep and far easier to use on low to medium mineralisation sites.
At the moment I've no interest in the new Whites at all as its not going to offer any extra depth over the GS5 on the wet sand and the limitations for land use are basically the same as for the 5 and the Infinium.

The training the dealers are going to have to undergo illustrate the problems of using ground balance shift to try and implement a form of discrimination. There's still going to be an awful lot up for resale within a short time when people find they are going to have to make a choice between having a degree of discrimination or best in-ground performance.

Brian

 

[Tom_in_CA]

Brian, Brian, Brian ..... how do YOU know that the new Whites is going to be like the GS5, eh? Haven't you heard the buzz? Whites merely started with that design, and did their own improvements to it, right? So maybe it'll solve those bugs you refer to, and be an VLF killer on land sites, for coin/relic guys! Yup that's it: Any day now, we'll be effortlessly digging silver dimes to pulse depths (1 ft) in parks, while effortlessly passing surface foil, nails, etc... right? woohoo!

 

[extractor]

I agree with Tom.

 

[U.K. Brian]

One of the reasons I bothered to come to the States a few months ago was to try a 5 against the Whites. If you read the reports you will find its George K. really pushing the Whites. Reg Sniff has more realistic views and where's the posts from Bob B. and Keith Z.
Greg (of Trans Bay I assume) is another who is supposed to have obtained fantastic depths but then he also spent a few years pushing the Whites Quatum range and we all know what happened to them.

To much hype and not enough facts and Tom, are you suggesting the Whites works or not ? (a) it won't be any day now with the limited handbuilt release only intended to act as a spoiler for the design they rejected and (b) you will still be stuck with the choice of greater depth (on bad ground) or average depth if you do want to use the limited discrimination. (c) Whites don't improve pulse machines they take a design and make it worse as per the Surfmaster.
By the way don't forget to ask how it does as regards target masking not just from both below but alongside the coil.

 

[thompy]

Brian, the quantums are great relic machines, very underrater

 

[U.K. Brian]

Worked great in my area, but not in many, so Whites didn't even bother to import the later QXT to the U.K.
Spectrums/Classics etc all worked well in any area so became best sellers.

 

[poddar]

Seems some folks are looking to shoot down the TDI without much knowledge of the product. Owning three of Eric Foster's Gold Scans seems to me to be a vote for the design. If White's can sell a similar product for almost half the price, where's the beef? Will the TDI butter your bread for you? Probably not, but if it performs as well as many vlfs in good ground, but also beats the pants off of them in bad ground, that's not a bad proposition. The discrimination may not be as good as a vlf's, but then, if Steve Hershbach is to be believed, it may be even better that some vlfs for coins! I suggest that opinions that are too strong in either direction for such a new product may be evidence of some sort of prejudice.

 

[Tom_in_CA]

I have airtested a TDI now, that my dealer just got. Granted, I haven't taken it out in the field yet, and granted, I only spent about an hour with it (reading the manual, and trying all the different settings). But based on what I saw in my air testing, it seems that it will only do high conductor coins (dimes for instance) at about the same as a good VLF discriminator, at best. Ie.: 9" if you really pushed it. That's no better than an Explorer, IMHO. Naturally, it will get nickels and low conductors deeper, in true pulse fashion. I guess if you have soil that is SO nasty, that a VLF just can't cut it, then yes, this would be the way to go. I have no soils in my area that are that mineralized, but I suppose some land sites might be that nasty somewhere.

There will no doubt be posts from folks who'll say they went to a "worked out place", and will find something that they will totally attribute to the solo ability of the TDI. It's bound to happen. But think of it: Every single day, on every single metal detecting forum, someone is posting a good find, that quite often comes from "worked out sites" (parks, CW sites, etc...) right? Heck, even cheapie radio shack machines sometimes go find a gold coin. And in our true spirit of competition, we'll quickly point out to our buddies "see? the Explorer trounces your Garrett" or whatever. I mean, I can go to places RIGHT NOW, that have been pounded to heck with every sort of machine. And if I try real hard, I/we are eventually bound to find something more good, right? The only REAL test of whether or not another machine could've heard the target, is to flag signals, and compare machines. That will be the only convincing test.

Regarding the TDI's ability to reject iron: The manual (that Jimmy Sierra wrote, by the way) specifically states that nails turned to their point, will not be rejected. Yes, you can reject them when they're lying flat, but you will find that the TDI will have a dickens of a time rejecting them standing straight. Of course, the come-back line to this is that "All VLF discriminators, of any brand, have some degree of weakness of various forms of iron". Yes, that's true, even the best vlf discriminator will be fooled by various shapes and sizes of iron. Granted. But in my humble opinion, this will be more true of a pulse. Based on what I saw with my air tests, I can only imagine a higher ratio of "getting fooled", with this. I can hunt for hours with my Explorer in most types soil, and NEVER dig a nail. And that's even while "grasping for the deeeeep stuff". Yes, in certain soil/moisture types, large deep rusty iron clumps try to mimic deeep coins, and do fool various vlf discriminators. But I believe that the "fooled" ratio will be higher on the TDI.

I'll be waiting to see this in action over the next year, and see what field results are. Will no doubt eventually be trading flagged signals with TDI users. Only then will any of these questions ultimately be answered. But in the meantime: 1) seeing as how no soil minerals in my area isn't tackled by a standard vlf, and 2) seeing as how I can currently reach 9"-ish inch on coins anyhow, and 3) seeing as how I have no trouble with iron with standard vlf's, I don't see a compelling reason to need a TDI. Perhaps on the beach, where a user would want to favor lower conductors, this would be great. In fact, they could care LESS about pennies/dimes, as they're not necessarily hunting for old coins. They're almost strictly looking for jewelry, and coins therefore, are almost a nuisance. I could see the merits of this machine in that environment.

 

[bakergeol]

Hi Tom

First off as Reg has stated in the past the TDI was not designed as a coin machine- gold nuggets/relics were on the top of the list. PIs are going to be hotter on low conductors. The TDI was only recently applied to coin hunting here in the states. I assume our high conductor coin hunting method is worthless to European efforts as they have a lot of deep low conductor coins. It is a American setting.

As Reg has plainly stated in the past regarding his "hunted out" park with a GS5. It was heavily hunted by the locals with their VLFs for decades. The reason cited by the locals for poor vlf performance was the presence of highly mineralized soil. George K has also confirmed in tough soil a PI like the TDI totally wacks all VLFs (Explorers etc) in the depth department. Living in the West near Reg I understand what high mineralized soil really means and it's effects on typical VLFs. Yes there will be a lot of parks with high mineralization where the TDI will do quite well. It really must be nice to detect in non mineralized soils only.

Perhaps an important reason for the success of the GS5 and TDI in coin shooting is- If it beeps- DIG. No iffy signals, no wiggles, no one way signals, no thoughts if it is deep iron or a coin- just DIG. No worrying about TID numbers- just dig. That is how Reg recovered that monster(1oz) gold ring in that hunted out park. Is VLF TID your friend or your foe?

Basically if you only coin shoot in low mineralized soils I really see no reason to buy a TDI. A top notch detector like an Ex or F-75(please no debates here) has all the depth you need with TID.

Regarding the TDI's ability with iron. I don't know as I have never used one- just the GS5. It is also doubtfull Jimmy was aware of the high conductor coin setting which was publicized by Reg and Steve. It is not a new technique as I posted information on this many years ago when the GS5 was first introduced. I ceased posting information on it as I was tired of being attacked on the forums for posting the impossible. You might remember our never ending discussion about distinguishing between nails and high conductor coins with the GS5?

Yes you can eliminate vertically buried nails with the GS5(I assume with the TDI as well) using the high conductor coin setting. Just increase the GB a little with a test nail vertically and there you go. It will decrease the depth a bit. For iron - no I do not believe the GS5 will be "fooled" by iron using the high conductor coin setting more than a VLF. It is the reverse as I feel the GS5 is superior. Put a gold bar next to an iron bar and it will readily distinguish between the two. Very large steel can versus 40 oz gold nugget- no problem. How about a trash can lid?- no problem with a ferrous determination. How many VLFs can do the above?

Is the TDI an Explorer killer in low mineralized soils? No not now. However, you mentioned in a years time you would have the answers. Perhaps not? Hopefully by that time we will be debating the merits of Eric's Afterburner( a tx boost for the GS5-I assume for the TDI also).The tested prototype made the GS5 deeper than the Minelabs top of the line PIs. Now that would be an Explorer killer.


Happy Hunting
George

 

[poddar]

Agreed that time will tell. As to your air tests, I received a TDI yesterday and started playing with it last night. I had no trouble getting a strong, though weakening, signal on a dime out to 10 - 11". I got even weaker and irregular signals out farther than that to what appeared to be 13"+. However, I only had a half an hour to play with it and my measuring procedure was not very exact: a ruler on the floor under the coil haning off the edge of my low slung bed. This was with the gain set to slightly more than 3 and not using the gb feature. I did notice that tweaking the threshold seemed to make a difference.

I am new to metal detecting. No axes to grind, no preconceptions. As an owner, I suppose I am in a position to want it to perform well. However, performance is relative to my needs. I'm nearing sixty and don't want to lug around a super heavy unit regardless of it's depth. I live in Central VA where much of the ground is very mineralized. I'm looking forward to trying the TDI at a well known creek that's the site of three gold mines from the 1800s. The creek still gives up small amounts of gold to the dredgers and sluicers that work it every weekend. Many of the prospectors have MXTs and GBIIs and they all leave the creek shaking their heads because their machines just won't work because of the extremely hot rocks and mineralization. I'm hopeful that a pi will do the trick. We'll see. I also leave for the beach week after next so I'm looking forward to that environment as a good place to learn how to use the TDI.

I know that any of you folks with experience can out hunt me regardless of the machines we use. I'm hopeful that a bit of persistence will reward me with a tolerable detector that can will work well just about anywhere and at any kind of detecting. Time will tell.

 

[bakergeol]

Agreed that time will tell. As to your air tests, I received a TDI yesterday and started playing with it last night. I had no trouble getting a strong, though weakening, signal on a dime out to 10 - 11". I got even weaker and irregular signals out farther than that to what appeared to be 13"+. However, I only had a half an hour to play with it and my measuring procedure was not very exact: a ruler on the floor under the coil haning off the edge of my low slung bed. This was with the gain set to slightly more than 3 and not using the gb feature. I did notice that tweaking the threshold seemed to make a difference.

I am new to metal detecting. No axes to grind, no preconceptions. As an owner, I suppose I am in a position to want it to perform well. However, performance is relative to my needs. I'm nearing sixty and don't want to lug around a super heavy unit regardless of it's depth. I live in Central VA where much of the ground is very mineralized. I'm looking forward to trying the TDI at a well known creek that's the site of three gold mines from the 1800s. The creek still gives up small amounts of gold to the dredgers and sluicers that work it every weekend. Many of the prospectors have MXTs and GBIIs and they all leave the creek shaking their heads because their machines just won't work because of the extremely hot rocks and mineralization. I'm hopeful that a pi will do the trick. We'll see. I also leave for the beach week after next so I'm looking forward to that environment as a good place to learn how to use the TDI.

I know that any of you folks with experience can out hunt me regardless of the machines we use. I'm hopeful that a bit of persistence will reward me with a tolerable detector that can will work well just about anywhere and at any kind of detecting. Time will tell.

Hi Poddar

Thanks for your input. Welcome to TN and we value your views and opinions.

Keep us posted on your experiences. This is a new machine and we are all learning.
I don't care how long one has been in the field- you keep learning.

Thanks again for your input

George

 

[Tom_in_CA]

Poddar, yes .... welcome to T'net. As I read your report of "10 or 11 inch" on a dime, I noticed too, that you acknowledge that this depth is with the GB off. That would not be a way for relic/coin guys to hunt. Yes, you go deeper with GB off. However, you can't reject nails in that mode. So only nugget guys, and *maybe* beach guys would hunt that way. But you could never hunt that way in most land hunting sites. In fact, to do so, you wouldn't even need a TDI. Any number of non-discriminating pulse machines have done that for oodles of years now. Sure, you could get a dime to probably 12" or more, and nickels to 16" or so. But no one would want to dig staples, bobby pins, and nails in the typical land site. Therefore, the TDI would need to be used with GB "on". Once you do that, your depth goes down.

 

[bakergeol]

Hi Tom

I believe this is what Eric posted for dime depths on the TDI.

7.5" coil GB off 10"
GB on 9"

12" coil GB off 11"
GB on 10"

George

 

[Tom_in_CA]

George, the unit here at my dealer's has the 12" coil. It certainly didn't seem like it could get 10" on a dime with GB on. I'll try it again though. Any suggestions as to the settings I should use in an air test to acheive this? (aside from GB on, of course). Thanx.

 

[bakergeol]

George, the unit here at my dealer's has the 12" coil. It certainly didn't seem like it could get 10" on a dime with GB on. I'll try it again though. Any suggestions as to the settings I should use in an air test to acheive this? (aside from GB on, of course). Thanx.

Eric balanced his with some ironstone.

I can not help you much except run it at 10uS. I found out awhile ago that my GS5 settings are different than the TDI. Reg modified mine for a multi- turn GB sort of like a GS5C. He also made some other mods and it is quite different and deeper than my original. Steve started at the total iron position around 1.5 or at the 7:00 GB position on the TDI. Use a screwdriver and coin and you can tell when you hit the sweet spot. This however is not the max depth for coins- for max depth take it outside in an area of low interference- a nice quiet environment and ground balance it for max depth with test coins.

George

 

[poddar]

Understood, Tom. Again, I just turned the machine on for the first time last night. I have a lot to learn.

I considered buying a MXT and then an Infinium last fall, but heard of the TDI and decided to wait. I bought it foremost for gold prospecting, but like the fact that I can perhaps use it for coins, beach, and relics too. I'll dig everything for a while until I learn a bit, hopefully.

I doubt that any one machine is going to be the best at everything. I figured the TDI would be a good entry level pi detector that would, most importantly for me, give me a chance at gold in highly mineralized areas. I've learned enough from prospecting for the past year to know that digging deep isn't really the most important part of prospecting. Digging in the right spot is more important. I suspect that will hold true for prospecting with a MD as well. I know I would stand a better chance at Moore's Creek than I will in Central VA regardless of the MD I use, but that's ok. This will be part of a hobby I enjoy. I don't need the best to enjoy it the most!

One final thing, I know someone will come out with something better before long. It may already be out there. Some on the forums seem to think so. It may even be White's! Or maybe the Nemesis will become a reality and out do the TDI. But I won't feel compelled to run out and chase the next 'best thing'. I expect that's it's more about the man at the controls than it is the machine he's holding. Right now, I need experience more than depth! Down the road I'll see what's available assuming the TDI doesn't end up in the pile of electronic hobby junk in my basement. If it does, at least it will be only a $1500 piece of junk instead of a $2,600 or $4,000, or more piece costly piece of junk!

For now, I'm looking forward to getting into this hobby. I think it will be fun. And maybe I'll find a bit of gold once in a while!

 

[Keppy]

I have a question... I have a video by Fisher ...called..Advanced Treasure hunting Techniques...with Thomas Dankowski he shows in a test garden the Fisher CZ-3D picking up loud and clear a dime at 11 inches...so that is as good as a PI detector and cheaper and a lot better discrimination right or wrong.

 

[Tom_in_CA]

Gadabout Jim, the Fisher CZ6 will do that too. Heck, the Fisher 1266 (which has disc.) can probably do it deeper still! The problem with all those machines though, is their disc. is weak. Beyond about 7 or 8", CZ and 1266 hunters will admit that deep rusty nails give them fits. Sure, they can do a lot of "second guessing" by trying to judge repeatable signals, or tricks like comparing the pinpoint spot to the disc. signal spot, etc...

If you were to ask some of those guys what the deepest coins they found sounded like, they might say "it was a one-way signal" or "it bounced between 3 different TID categories" etc.... And then when you ask them how they discern deep nails, they'll tell you "they are one way signals" or "they'll bounce between too many categories". So bottom line is, if they want to continually get the 11" you saw on that video, they'll have to compromise with a lot of other similar sounding signals, that will turn out to be junk.

I hunt side by side with a CZ user. He does great in furroughed field hunting, and the beach. Admittedly goes DEEP. But when we get into a turfed park, I will sometimes point out a signal that I think is going to be a deep coin (wheatie or silver at 8" etc...). He'll go over it and get it WITH ROOM TO SPARE! But the problem is, he moves over 1 ft. and gets similar signals elsewhere too. In other words, it has much less tell-tale disc/TID than other discriminators on the market.

And as aside to the 1266: It will "hit a brick wall" at about 5" in even moderately mineralized soil. And forget trying to use it on the wet salt beach. So you can see, that the power-house depth you saw in that video, does come with drawbacks.