Tom what detectors do you like best and why?

Yes, this is the one that I demonstrated at a few different club seminars/presentations.........along with a couple of FMDAC conventions.

Okay, I know I want one, put me on the top of the waiting list.
Please let me know if your looking for investors.
Aaron

Tom

I think you mentioned that this was your favorite detector along the towel line. So what does AU21X stand for? My guess is Gold(AU)@21(inches)or
DEEEEEPER!!!! How"d I do?

Au = Gold
21X = Twentyone times better at identifying trash

Tom

That's quite a phenomenal improvement. Would it just apply to dry sand applications,or would it work in the dirt also?

I ONLY recommend its use in the dry sand........yet, some folks of whom have tested it.....had good success in dirt with it.

How about low mineralization dirt like up here in SE Mi.?

I ONLY designed it for dry sand! It would probably be okay for dirt.......but original design intent is for dry sand with tons of trash.

NASA-Tom Wrote:
-------------------------------------------------------
> White's new TDI is the same as the AquaStar-II &
> the GoldScan-5C. (((( The AS-II & GS-5C share the
> exact same Xmitter )))). BUT...........the TDI has
> one measurable concern. It's a mass 'production'
> unit; subsequently, its tolerances are not as
> 'hand-crafted'.....as the AS-II & GS-5C. I surmise
> its pulse delay is in the 13uS - 14uS
> range..........whereas the AS-II & GS-5C are right
> at 10uS. This makes a BIG difference in real-world
> performance..........especially with small gold.
> Yes, the White's TDI is a Eric Foster
> release.....through White's. ------ So
> far........Eric Foster is yet to be 'trumped' in
> PI design/performance. Bruce Candy (Minelab
> brainchild) holds the record for PI performance in
> Australia dirt......esp with GPX-4500. Still
> waiting for Dave Emery (Pulse Devil) to 'level'
> the field......and not sure it'll ever happen.
>
> The 71Khz Gold Bug-2 does not have enough Ground
> Balance range to accommodate wet salt. No joy
> here.
> (( Let's wait and see how the 19Khz Tek G2
> compares.........when its released )).
>
> No further comment on V3.
>
> With the advent of the 'boost process' ('bp' mode)
> on the LTD; this poses a dramatic departure from a
> standard F75... IRT real-world application.
>
> Tom


Tom is there any way to tweak Whites DF PI to 10uS? If so can you provide info on how or where to send it? Thx

It might be possible.....but I have my doubts. A assembly-line production unit is NOT up to par with extreme performance tolerances......as this would be too hard to ascertain for general production. So far........it has been only Eric Foster........of whom builds PI units by hand......one at a time.......and can give 'extreme detail' attention to exceptionally tight tolerances. A perfect coil is the starting-point for 10uS capabilities. It's not easy! ((( But not impossible ))). And if you ever have the opportunity/experience of hunting with a 9uS or 10uS pulse delay PI.......you will instantly realize how 'blind' all other detectors are to the large volumes of small gold items on these wet-salt beaches. It's an eye-opener......that you would never even realize exists.

I just had the opportunity to test (at KELLYCO) and then............ironically....the next day.......at the wet salt beach; three detectors:

Whites Beachhunter ID
Whites TDI
Minelab GPX-4500

The Beachhunter ID failed too many tests (I'll spare all the details).
The Minelab GPX-4500 is more powerful/sensitive to small gold (and......obviously larger gold targets) than its predecessors; SD-2100 & SD-2200, . , . , . yet.........lacks in performance .... across the spectrum (on a wet salt beach) than/as compared to..... the Whites TDI. The Whites TDI wins.....hands-down..... for sensitivity to small gold......and depth dept also. Lest we not forget to mention the TDI is less than $2000........and the GPX is close to $5000. Never assume 'more dollars' automatically equates to 'better performance'. The TDI also sports a waterproof coil. The GPX coil is not waterproof.

The TDI is a detuned (because of assembly-production) GoldScan-5C......in Whites clothing.

FYI

"Tom is there any way to tweak Whites DF PI to 10uS? If so can you provide info on how or where to send it?"

jamt225, Not Tom but perhaps I can help on this.

The Whites DF PI is a version of the original Whites Surfmaster PI. As far as the pulse delay it's now at 15 µS. It would take quite a bit of circuit re-design to get it to 10 µS.. If even you could, we still have the problem of the coil. A new coil would have to be designed to operate at 10 µS.. The Surfmaster PI's coil is not interchangable with any other PI. Quite an expencive undertaking.

Mr. Bill



Edited 1 time(s). Last edit at 07/09/2010 11:40AM by Mr.Bill.

I am looking at some other alternatives for deep coin detecting....
In my area there is extreme iron/mineralization and trash that makes the ground VERY noisy.
My current setup is not performing the way I want so am looking at my 3rd detector change in as many years.

I have done a search and so far the new F75-LTD has yet to hit the shelves except for the prototypes.
(Even the Fisher site does not mention it... Yet...)

[www.fisherlab.com]

Any ideas on switching now or waiting for the new F75 is the best way to go?
I have read up and trust the advice here very much. Thanks all!!

You say your ground is 'extreme mineralization'. For this........I recommend the Minelab Explorer/E-Trac. Yet,,,,,,, I still doubt it'll do what you want it to do......as it will 'null' in heavy iron trash. To date; nothing can 'see through' one metal object and detect another metal object..........then report only the 'other' object......and also give it a proper ID. Not a chance. Not capable with electromagnetic-principle operation/detection devices (our current-day metal detectors). The "shock" as to 'how many doors would open' .....if we had such a device!


.............Also; 10uS (or less) pulse delay devices are difficult to create...and are not to be taken for granted! They must be hand-made.........one-by-one.

Many Thanks Tom!

The amount of "feedback" I get in my current hunting grounds is quite a bunch with my SE. BUT - There is a ton for the detector to report back on as well.
"It's job is to read metal. Not just the good targets...." As a famous person once said on his DVD...
Funny but Decreasing Sensativity has been a real help and still allows acceptable depth for my target coin range AND a little less feedback at the same time.

Sometimes a small calculated punch is much better than
an all out bombardment to look for the same target.

An F75 or a great beach machine is still on the horizon.



Edited 1 time(s). Last edit at 07/09/2010 11:05PM by SilverPeter.

Hi Tom,

In reference to your statement "The TDI is a detuned (because of assembly-production) GoldScan-5C......in Whites clothing", I think that may have been closer to the truth when Whites first started making the TDI. Today, the surface mount units have the timing set by microprocessor so there is no way one can error on the adjustments.

Also, the people are more experience at White's now, thus making the "assembly line" far more accurate and consistent. Most of the components are now placed by a robot so errors are minimal. So, the TDI today is worthy of its name and quite competitive to the GS 5. The new Pro is even better because of the refinements suggested by Eric Foster after his trip to OZ. Those adjustments were recommended to make the TDI better suited for the harsh OZ mineralization.

BTW, so people know, I don't work for Whites or for Eric but I do have a long standing friendship with Eric and very familiar with the GS 5 design and its evolution at Whites. How well do I know the TDI? Well, before the TDI existed the single tone feature existed on only one detector and that was my GS 5. Today, it is used by a lot of the TDI owners as a means of eliminating trash or separating one target from another. It is a great but underused feature.

As for any comparisons between different brands, I hate doing that because it is easy to make one detector look better than another, but your discussion as to what happens on a saltwater beach did catch my eye. Now, I am wondering how well the TDI will work on the salt flats in OZ. I hope we get feedback from people over there and how it does in different locations.

I personally use the TDI for a wide range of hunting simply because I like the detector and its quirks. I enjoy hunting gold with it, but certainly don't mind using it in a park either. People must keep in mind that I have been using a PI for years now, so the things that irritate a novice PI owner don't bother me at all. To the VLF owner trying to figure out a PI, the TDI can easily seem "backwards". To a PI user who has never had any form of real discrimination, the TDI is truly unique and fantastic to use. So, people are going to have different views. The key is for any new owner is to give the detector a chance and take the time to better learn its quirks since there are going to be many if one has never used a PI before.

Anyway, I just wanted to toss in my opinion and thank you for providing an idea of what to expect when beach hunting with the TDI. For those wanting more general info on the TDI, there are a few forums specifically for the this detector and you can usually catch me on one of them since I try to visit most of them on a regular basis. On the down side, the forum with the most info is down at the moment, but I hope it isn't down for the count.

Thanks again,

Reg

Thanks Reg
Great post. Your knowledge and straight forward honest approach really fit's well on this forum.
I live on the west coast of Canada and deal with lots of hot rock's and mineralization on the salt water beaches. Tom's comment's and your very educational guidance on the operation of the TDI have made me decide that when I finally buy a PI it will be the TDI.
I also am watching with great interest the development of the QED. Do you think it will have any of the same disc. capabilities as theTDI or will it be a deep gold machine only.

Thanks again for responding.

Turtleman
Tom

Hi Turtleman,

I haven't followed the QED as closely as I should so I can't say for sure just what type of discrimination it will have. I suspect it will be superior to many other PI's, though. Again, it is hard to tell since most of what is being done is in software. According to what I have read, the QED should be a very capable detector, depth wise.

I can understand why the designer doesn't want to introduce the QED before he is satisfied, although I am not sure I agree with it. It is extremely easy to miss things that can cause criticism. I know I have done that a time or two myself. Not finding something at the onset does sort of leave egg on one's face. I recently ran into that on one of my mods, but ultimately that same flaw led to a slightly different approach and new ideas, so I am one for tossing an idea to the wolves to see what surfaces. One does have to keep in mind that I don't mind criticism as long as there is some intellect behind it.

I wish bugwhiskers the best in his development of the QED and hope to see it available soon.

Reg

Hi Reg,

Your candid response does prompt a few more questions......but mostly on my end. I tested a pair of TDI's (not Pro's).......did not think to look at 'serial numbers/production run versions'..........subsequently, not 'triggered' to think that there may be newer versions that may pose substantial performance deltas over the first batch.....as.....in my eyes.......... the TDI is so new....(( I have not been following TDI status/history ))........surely there could be no newer unit/variation...................and certainly not available to the public (yet). So, , , I stand corrected.

As far as the 'build quality' of White's.......Kenny White/Alan Holcomb run a tight ship; justified, validated and verified. Sparing details, I have used/tested MANY White's products (several being MXT's).....identifying hair-splitting vernier analog set-up config......from unit-to-unit.......to be quite 'stunning'......to say the least. This is with their VLF IB units...........and, I suspect there would be no difference in the PI Dept. Quality has never been a 'issue' with White's. (On a tangential note; White's advertising/PR Dept is 2nd to none......and never to be overlooked/underestimated). Now, on a overall rating; White's has (most) always produced average/above-average units.....IRT real-world performance. Not the deepest; not the fastest. In the VLF world; there are other (better) choices. HOWEVER; I think White's...........FINALLY...............has a pinnacle trump-card.............for the first time, in a long time. (Nearly all credit goes to Eric Foster). Frankly, I'm glad Eric chose White's. (I was going to meet Eric & Carl in Key Largo a few days ago; but plans changed).

As far as the TDI, I still have two major concerns. I have (near) certainty that the TDI will fail to Grnd Bal on certain Florida beaches.....rendering any/all of its ID capabilities useless. I say this in part due to the GoldScan-5C failing to Grnd Bal in wet salt. Bill Crabtree has flown down to Florida to meet me on two different occasions..........specifically to verify GB failure on the 5C. The second time was just a few weeks ago. Bill may have been 'stunned'; yet, I am accustomed to this condition......also to include a not-so-normal SAT speed requirement. I may be ignorant of add'l mod's to any/all newer version(s) of the TDI that may mitigate/circumvent/correct this issue; yet, my doubts remain pique.
The second issue is; I am SPOILED by the AquaStar-II; of which far surpasses the TDI......IRT small gold detection in wet-salt. (This is to include the performance level of the 5C; hence, my comment about 'detuned GoldScan-5C). I have a calibration test-standard (a 18Kt gold crucifix slightly taller than a quarter) that the AquaStar-II will acquire at 4" nominal wet-salt depth. The TDI will only detect it when I literally scratch the bottom of the coil with it. This sounds terrible...........but................mind you.............no other production unit will detect this test-standard AT ALL.......including the GPX-4500........AND any/all VLF units. This is why the TDI promises 'hope'; subsequently catching my eye. I suspect the TDI produces a true 11.6 - 11.8uS pulse delay.....which, in turn.....is the primary reasoning behind the 'why' as to its performance level. If only to create/ascertain a assembly-line/production-run 8uS TDI (w/corresponding inductive/capacitive-correct coil).......so as to religate all other beach units to e-bay enmass.

((( Is the TDI 'salt-air' and/or splashproof??? )))

In no way am I 'endorsing' the TDI; mind you, I only tested a consumers unit for 7 minutes in a exacting; nearly textbook wet salt scenario....thankfully. Enough to validate a couple of critical tests ONLY. Initially: quite impressed; yet, Grnd Bal and 'huntability' are paramount for any form of true rating. All eyes are on this one!

Tom

Hi Tom,

There are two TDI's out there today as far as I know. One is the original 200 through the hole boards and the rest are the later surface mount units. The way to tell the difference is to look at the conductivity switch. The original units only had the basic info at the switch of High, Low, and All. The later surface mount versions also contained additional lettering with something like GEB ON REQUIRED.

Do you remember which models you tested?

As for the actual delay, there are different ways of measuring that delay and they seem vary by a couple of usecs. I don't have one of the newer units and to be honest, I adjusted my through the hole board unit to a delay of less than 10 usec. So, I don't know what it was to begin with.

I would like to see the minimum delay be set at less than 10 usec but have a 2 usec switchable lower end. The problem is, new owners will always try the limit and at 8 usec strange things can happen. I am sure Whites doesn't want to be constantly trying to explain these nuances as normal. So, the only solution would be something that had to be added after the unit was purchased and maybe signed for.

It is extremely difficult to build coils to operate at less than 10 usec, let alone 8 usec, but it can be done on an individual basis. This is one area where the factory line does run into a wall. Sampling on the decay curve can cause strange things to happen as I mentioned before. However, if a person knows this and is aware strange things can occur, most people will accept what happens as normal or at least ask before complaining to the factory.

One of the reasons I like the original through the hole board is the ability to adjust the delay back to less than 10 usec. That can't be done now on the newer models. Personally, I wish that ability was built in so it could be modified if so desired. Now, one would have to program the microprocessor which is more than I would want to do.

It would be interesting to actually check the units you have used to see if in fact the Aquastar and the Goldscan 5 C you used have been tweaked a little, rather than the other way around. At least, it is something to think about since both contain the circuitry that will allow tweaking to a shorter delay.

It is too bad you didn't get a chance to meet up with Eric and Carl. I am sure both would be quite interested as to why ground balancing wasn't possible. Given some time and one of the GS 5's, I have a feeling Eric could adjust the GS 5 to work.

BTW, when you say you can't ground balance the TDI there, does the detector simply lack sufficient GB adjustment, meaning it needs more adjustment or the minimum is too much?

Reg

Hi Tom,

I just talked to Mr. Bill about the beach and the Aquastar and possible GS 5 you may have tested. After talking to Bill, I feel there is a possibility your units you tested may have been tweaked to the shorter delay, thus leaving the impression the later made TDI's have been detuned.

So, after my discussion with Bill, at least this may be why there is a difference between the detectors you tested and the White's PI.

Bill also tried to explain the conditions he experienced on the beach and the difficulty trying to ground balance. I forgot to ask Bill if this GB problem could be experienced on both dry and wet ground. If so, it would be interesting if a large plastic zip lock bag of the sand would generate a signal if waved over the coil. If so, then most likely something quite conductive is part of the sand matrix.

Also, if this the case and this conductive sand extends for a long ways along the coast, one might have to look at the coral in the area to see if that is the source of the signal. If so, then it may take an analysis of that coral to determine what is happening.

Personally, if a bag of the sand will cause a signal, I would like a bag of it if possible to play with. The typical GB system has a maximum adjustment sufficient to eliminate signals from basalt or at least most basalt. I suppose it is possible to increase this level some. However, before doing that, I would like to look at the decay curve of this sand.

Reg

Hi Reg,

Sounds like I had tested 2 of the first-gen TDI's.....(now that I know there are 2 variations). "GEB REQUIRED" did not exist. IRT the GS-5 (2 tested about 1 year apart from each other).....incurred the same GB failure.....but ONLY in WET salt sand. Dry sand had no problems. Problem encountered with Grnd Bal of GS-5C; adjusting Grnd Bal the entire spectrum would make absolutely no change to large response to ground whilst bobbing coil; subsequently rendering ID Cktry non-functional.

Yes, my particular AquaStar is modified for approx 8uS. Without the adjustment (and at original 10uS), my test-standard gold cross was detectable to approx 2.5"..........still a bit better than 1st Gen TDI. Not sure if Bill made adjustments to the GS-5's before bringing to FLA for testing. I do not suspect such intent.

I have become keenly aware of the fact that professional training is nearly a requirement of today's hi-powered PI's...........and absolutely mandatory for units that ascertain a true 10uS pulse delay.....and especially less, such as 8uS. Yet, with proper education; a 8uS pulse delay unit will revolutionize a detecting world that is 'unknown' to the general public. ((( And this is only a 'start' ))). How do you know what you are missing........if you do not know it even exists.

Technologically, I wonder if there is a Mfr'ing process that would make 8uS capable coils suitable for max ROI.

I am in accord...........and fully concur with your comment about having a switchable (I prefer via 'lock-out' feature) option of ascertaining 8uS ..... to be reserved for 'seasoned' PI hunters.....for obvious warranty/unseasoned GP return issues. Mitigate @#$%&'s box.

Collectively, I applaud the concerted effort of Eric + PI + Whites to tackle this 'pushing-the-envelope' general production TDI with aforementioned accolades. Most Mfr's run the other direction. ((( I'm in the business of pushing-the-proverbial-envelope of going where no man has gone before; thus, can only commend daring feats ))).

Reg..........Did you let Eric know about this post/thread.......as he (just returned to England) and e-mailed me about 'some post' that he was 'informed' about.... and thought it was one of mine?

(Feel like I forgetting something).

Tom

Hi Tom,

Eric is aware of the thread but I believe his busy schedule and the long flight plans most likely prevent him from responding at this time. Also, I do know he has a lot of specific work he has to deal with as soon as possible once he returns home. Eric is a one man company doing the work of a dozen people. I can only hope I have his drive and stamina when I am his age. So, I suspect he will focus on his obligations first before becoming involved in any at length discussions. At least that is my guess for a while.

As for a PI that operates at 8 usec, yes it can be built. I know I have a couple of them. In fact, there have been discussions on some of the prospecting forums some time back about "invisible nuggets" that PI's couldn't detect. The discussion was first brought up by John Blennert who found a lot of nuggets down near Tuscon that his PI couldn't "see". Some of these nuggets were reasonably large, in the several gram range.

I asked John where I could buy a couple of these nuggets for testing and he was nice enough to send me a couple. He also sent a couple to Eric. (BTW, John was nice enough to send me a truly "invisible 1 oz nugget that is truly invisible. I still can't detect that one, but I do respect John's humor.)

Now, the ones I received weighed over 8 grains and together were about as large as a fingernail, which was large enough I thought would be a snap to detect with my special modified PI. As it turns out, I could detect them but barely. What a shock that was!!

It took a while but to make a long story short, my detector and coils were redesigned to work at a shorter delay and I was able to detect these same nuggets at a distance of about 4". To do this required some unique changes but it can be done.

Also, I feel it could ultimately be done on a production basis. However, I have run into a couple of things I feel could enhance that ability even more but need to refine the technique.

Now, as you probably know there are always surprises lurking in the background that can alter one's plans, so how this will finally work out is still to be determined. I wish I had more time to focus on the issue but personal matters are consuming much of my time at the moment.

Reg

Reg,

I certainly hope your Dad is doing okay. I have aging (or is that 'aged' parents). Time certainly has a price. I only wish I could share more experiences with folks; yet, lack of time certainly is inhibiting.

Yes, I too..........have plenty of invisible gold targets (jewelry form). Most were found with the 71-Khz Gold Bug-2. No other detector (especially in 'salt' mode) will detect these targets. Some are quite large........and present plenty of arm-chair.... table-top lengthy "show-n-tell" discussions. Percentage-wise; it is the gold 'crosses/crucifixes' that pose the largest.... size vs. lack of detection.... eye-openers. Open-hoop earrings are next on the list.

Tom, at some point, could post a picture of that crucifix for size, shape and weight estimates, especially thickness? I'd like to find one similar in my collection that would be comparable for testing my detectors.

Better yet, I'll post the one I have and see if it's comparable to what you're using (providing that's allowed). Still working on the bench test, but finding time to get down to the beach for testing has been daunting.

Sure..........post two photo's. One of the extreme macro close-up of the Kt marking................and the other photo of a somewhat faded copper penny with the cross on top of the penny. ((( If the penny is too brilliant....... the cross looks 'washed out' ))).

I want to post a photo of two of my 'test-standard' crosses...........time permitting.

Thought I'd bump this up and see if there are any changes or updates. Thx

In the thread titled "CZ owners - Salt Training 103".... is where I posted the photo..........(if this is part of what you are refering to).

Thanks Tom I'd missed the "cross" info this summer as I have been away from the Net most of it.

Jesus is always there to help us if we just let him, huh? Easy to wear also.

Not exactly why I made the post, but it's great info as always. I was seeing if any new machines had made your list, etc. Thx