Jump to content
Nugget Shooter Forums
mariposagoldbag

Whites TDI Pro Vs TDI SL Vs Garrett Infinium

Recommended Posts

Well I finally got up the money to upgrade from my Fisher Goldbug 2 to one of the newer PI machines. I've been doing a lot of research on all of the above machines but still i'm not sure which one to go with. I've been watching this video...

http://www.youtube.com/watch?v=MhXl510qrXY

This guy does a side by side comparison of the TDI Pro and the TDI SL. His results show that the SL has a much smoother Threshold tone than the TDI Pro, but that the TDI Pro gets much more depth. Can anybody out there verify this test? And how does the Garrett Infinium match up to these machines?

One of the biggest features I'm looking for is an Iron Discrimination function. I know everyone says to search in all metal mode and dig everything...but when I'm working an old cabin site I wanna be able to eliminate the square nails and small tin and what not. I know the Infinium has this option, but what about the TDI? I read the manual for the TDI Pro and it talked about discriminating out hot rocks and Iron by using the ground balance? I would like to hear all of your opinions on which machine you think is the best. I'm looking to spend about $1500, should I be looking at some of the old Minelabs? What do you all think? Thanks!

Share this post


Link to post
Share on other sites

"One of the biggest features I'm looking for is an Iron Discrimination function."

For cherry picking I'd rather use a VLF like the Sov or F75 or even the GB pro. Much better target id and separation.

Share this post


Link to post
Share on other sites

Hey Chris. Thanks for the info, I had a feeling someone would bring up a few other detectors other than the PI's for the discrimination. I still intent on heading out your way one of these days, maybe sooner than later.

I would still like to know how the TDI Pro does with the discrimination, can it discriminate out small Iron while still finding the gold? Would also like to use it to coin shoot a little here and there. All info would be appreciated!

Share this post


Link to post
Share on other sites

You might do a search here for postings from "Reg" he is the TDI expert.

I do recall him stating that he was able to knock out the iron and still hear nuggets in the 1/4 ounce range.

Generally VLF do better at discriminating small ferrous targets then large ones whereas ML PI's are just the opposite.

Share this post


Link to post
Share on other sites

I just got finished reading the post from Reg that your referring too, very insightful...thanks! It seems to me that I'd be better off getting a used Minelab GP Extreme or a SD2200, the question is which one. Would you guys say that the two Minelabs mentioned would be a better choice than the whites or garrett? I don't know nothing about the Minelabs, so all info is most defiantly welcomed.

Share this post


Link to post
Share on other sites

I have a regular TDI and my buddy uses the TDI SL. Both work great but unfortunately you are going to have to dig those little pieces of iron, no way around it from what I can tell. You do get to learn the different beeps on iron and good targets in all mode. The little pieces of flat iron drive you nuts but they register good so you dig them up. Just get a good pick with a great magnet. Saves a lot of digging and most pieces of that little iron are on top of the ground so the magnet picks them up pretty quick.

The guy in the video is Jason, hes a good guy, met him once and on other forums.

On my TDI the machine seems to eliminate old nails better than the SL model but they both work fine. if i use the low tone mode for good metal and tweek the settings you eliminate enough metal that digging a few pieces is acceptable IMO. Most places you detect have been hit to death so just grin and bear it........ dig everything up. Cant tell you how many pieces of gold I have found under old nails. This is what you have to do unless you are on private property or something that has not been hammered to death.

Share this post


Link to post
Share on other sites

If I had a choice, I would take the Minelab over the TDI. And yes, I had one of the original tdi's. Keep looking and you can probably pick up a gp extreme or maybe even a gp3000. The small cost difference is a really big advantage. If it were me, I would rather wait a few months and try and save a few hundred dollars to get a minelab.

Share this post


Link to post
Share on other sites

Maybe I'm not reading these posts closely enough, but there's a huge glaring fault in that test ... The signal from the coil goes down in a cone shape and those targets shown are so close to each other that many of them would be picked up in a single sweep of the coil ... Unless I'm missing some obvious aspect of this test, it is absolutely bogus to prove anything about coil, detector or the spin of the earth ???? Cheers, Unc

Share this post


Link to post
Share on other sites

Thanks Matt, I think you right. I'm going to try to get my hands on a GP3000 for a good price.

Share this post


Link to post
Share on other sites

I was wondering if anyone here might know of a youtube video showing how the Minelabs discriminate Iron. I looked everywhere.

Share this post


Link to post
Share on other sites

Don't ask me....I think Minelab should eliminate the discriminator on a gold machine....after all you already have

two of the best discriminators made.....your eyes!! :twocents:

Share this post


Link to post
Share on other sites

I's go for the new Fisher Gold Bug Pro anytime anyday and in every way. Trinity AU is absolutely kickn' butt in many patches he's hammered for years with his minelabs. Here in the Golden Crescent it tough ground to work ,he has a few buds who also bought the GB Pro(some newbies) and even they are pulling many righteous nuggets too. Ray used to post here but????? sure sent me some sweeeeeeeeeeeeeet pics lately-tons a au 2 u 2 -John

Share this post


Link to post
Share on other sites

Hey John, you think it would be wise to sell my Gold Bug 2 and get a Gold Bug Pro?

Share this post


Link to post
Share on other sites

I believe you can gain a lot of info on Treasurenet forum search for posts made by a fellow named Hemmingway. He has done alot of testing and comparasions with the Infinium.

Share this post


Link to post
Share on other sites

Mariposa...

I don't put any stock in the video you posted. Why??? Well, the TDI and SL are two different detectors. One of the things I have harped about was the difference between the TDI and the SL. Well, the guy in the video and those on his forum have gone out of their way to call me about every name in the book because they feel they should be the same and when they find a difference they whine like children. So, I don't agree with their tactics or their logic, or lack thereof.

Now, with that said, if you watch a very small portion of the video you will see two perfect examples of what I am talking about. First, I need to explain something and state again that the TDI and the SL are two different detectors. There are a lot of similarities but there are a couple of fundamental designs differences also. This means, you can't set the two detectors identical and expect them to perform the same. The problem with many on a particular website is they get upset when they can't run the SL detector the way they want or think is should work, rather than the way it should be run.

Now, the video does point this out for those watching closely, you will notice something on the video when they test the SL with the 1 gram nugget. They claim they can only hear the target in one direction, right? Listen closely at the end of that test and notice they can hear the target much better and in both directions. Why? Simple, the the target was moved at a slightly different speed.

I have harped that when using the SL, the proper technique is to operate the detector very slowly and smoothly. Now, in the video, they are testing backwards, meaning they have the coil stationary and moving the "world with its targets", right? Wrong, but that is another story. What can't be seen easily is the actual sweep speed a person might be using to obtain the results they do.

What can be seen is when the guy moved the nugget just a little slower, they could suddenly hear the nugget in both directions. Operate the detector at a nice slow deliberate pace and it gets even better, but rather than do that, certain people want to operate the detector however they want and demand the detector perform the way they want. When it doesn't comply, they scream foul and complain something is wrong with the detector.

Next, which I probably should have placed first is to discuss the bounce signal the guy complained about when he tried to ground balance the detector. Had he not been bouncing the coil but moving it up and down slowly like is done by digger bob in his videos, that "bounce" signal would not exist.

Now, I found that bounce signal to have some unique advantage, but because of the complaints, a simple mod which was nothing more than adding one resistor eliminated that signal. So, that bounce signal is no longer audible. However, that doesn't change the filter characteristics also related to the bounce and the one way signal will still exist if the coil is swept too fast. Again, slow down the sweep speed and the signal becomes a two way signal and the depth increases accordingly.

I figured out a little more about what the bounce is happening but that isn't for debate or discussion for that matter. What should be pointed out is on the newer units, the bounce signal shouldn't exist or be very minimal at the most. Just as important is the fact that if a person has one of the very first, they might want to check with the factory and have the mod installed on their detector. It does make operating too fast much more pleasant.

Now, one truly stupid thing done in the video is to arbitrarily set the the frequency control. Why have it if one isn't going to use it properly, right? What the decision to set the frequency control at mid position and leave it there is simply showing that the guy doesn't know squat about the detector.

To sort of explain this frequency control, I will relate something similar that is part of the setup of the SD2200 and that is to reduce the effects of noise. To do this, one has a time consuming procedure of holding a button, raising the coil and moving the coil to find the loudest noise. Then one has to wait until the detector beeps letting the operator know, the detector has found the best frequency the detector should run at to have the least noise. It is this setting on the SD or any PI for that matter, that will allow one to hear the weakest signals.

So, on the SL and TDI, the procedure is different. On them, one should adjust the frequency control SLOWLY (YES I AM SHOUTING) while listening carefully for the setting that has the least amount of noise. On the SL, this adjustment should probably be done with the gain at maximum simply because the noise reduction circuitry makes it difficult to hear the noise.

Now, here is the obvious reason once a person understands what is happening. On any PI, excessive noise or chatter makes it impossible to hear the very weak signals buried in that chatter. Eliminate or minimize the chatter and one can easily gain inches in depth of detection. On the SL, this is very important because the special noise reduction circuitry is trying to eliminate that chatter, but in the process any very weak signal buried in that chatter is eliminated also.

This elimination is the only way it can be done since the noise or chatter is a variable signal that can last for some time. So, to obtain the best depth on any PI, the detector should be adjusted to eliminate as much chatter as possible.

Are you getting the picture of why I say don't put much stock in the video? Well, a lot more mis information can be found on the website associated with the video, so be careful of believing what you read.

So far I have given you some information that is important to know when operating the TDI or SL. Now, I will give you a little more but it requires you know a little more about the difference in the detectors.

The TDI is built about the original GS 5 design which uses a 14 volt Li Ion battery that shuts off when the voltage gets down to about 12V or actually a little less. This particular battery actually charges up to about 16V. So, a fully charged TDI battery can be 16V or very close to it.

To cut down on the weight of the SL and make purchasing batteries cheaper and easier for the operator, the power supply design was altered so the detector could operate satisfactorily on 8 AA rechargeable batteries. With the nominal voltage of 1.2V for the rechargeable battery, the operating voltage becomes less than 10V much of the time. Keep in mind I say nominal because the fully charged battery will be higher than the 1.2V.

Actually, the SL is designed to operate at or down to about 8.5V before the battery alarm begins to tell the operator it is time to change.

Now, even if the circuitry of the two detectors are the same, do you see a difference? A fully charged TDI has almost twice the voltage applied as a nearly fully discharged SL. Will that make a difference? You bet it will. However, the depth difference normally won't be as much as displayed if one is using factory coils. Use a smaller coil such as the elliptical Jimmy DF coil and this petential depth difference becomes even less.

So, compound any serious battery difference along with improper setting of the frequency control and then toss in a larger coil and anything can happen. Furthere compound this with trying to operate the detector way too fast for its design and you can make a really good detector look bad. This can be further compounded by not knowing anything about the ground balance (GB) and how its adjustment can alter the depth of detection of various objects including certain sizes of gold and it only gets worse.

This is why I harp on people to learn their detector and all its quirks. Now, just for the record, this recommendation doesn't just apply to the TDI or the SL, but also applies to the ML's. Yes, sweep speed is very important on the ML's, especially when in trashy areas. Again, this is a subject for discussion on a different post.

The point of all of what I have written is there is a whole lot of bad info out there posted by people who are legends in their own mind because they have owned a detector for a while. So, it is not just a good idea to believe something because someone owns a detector and they make a video or worse yet, believe that the video is going to tell you something you should know.

If you don't believe me, that is fine, but just look at drivers out there on the streets and freeways. Most don't know the laws and many don't even care because they have been driving long enough that the world is theirs. Here in Colorado, I swear half of the drivers don't know they can turn right on a red light. Those that do know they can turn don't know or don't care that they are supposed to stop first. Would you want those experts teaching you or your kids to drive?????? This same mindset should hold true for using a detector. The only big difference is with a detector you will simply not find much if you follow or use bad habits, while with a vehicle, making mistakes or using bad habits could be a matter of life or death.

Getting back to the TDI and the SL, what works for the TDI may not work that way, with the SL or any other detector for that matter. The truth is, there is an ideal sweep speed for every design that works best and once a person gets in the groove of that sweep speed, one will have better success. Also, the battery voltage is more critical on the SL and should be checked more often. Using recargeables works fine on the SL but should be swapped out more often and not wait until the light comes on.

Personally, I am using Li ion batteries on my SL and swap packs every few hours. I also use nothing larger than a factory coil and because most gold found now is small, I use the smaller coil to make it easier to get closer to the ground plus will detect smaller gold better.

The SL, or the TDI for that matter, is not a ML so don't try to mimic what ML owners do. The design of the TDI family, including the SL is such that going to a larger coil may not get the results you think it would. A larger coil may work well for relic hunters looking for large objects, but one could easily begin to miss small gold.

Well, I hope this helps clear things up. Now, I probably should duck because I am sure some weekend warrior (one of the so called 3 day old experts) will try to wreak havoc on what I have just posted.

Reg

Share this post


Link to post
Share on other sites

Hey thanks for that long and detailed explanation, I really do appreciate it and it will also help a friend of mine who has been debating the two different detectors. As for me, I think I'm going to try to find a Minelab GP Extreme or a Minelab GP3000...if I can find one for a good price.

Thinking about selling my Gold Bug 2 and getting a Gold Bug Pro. I like the Gold Bug 2 I just wish I could adjust the discrimination level.

So John, let me know.. Is the is the Gold Bug Pro getting the same depth as the Gold Bug 2, and same sensitivity...or is it better, worse?

Thanks to everyone who posted on here! If anyone thinks there's a better option out there for me other than the Minelabs GP Extreme, and the GP3000 please let me know!

Share this post


Link to post
Share on other sites

I have decided to add a little bit more about the chirp and how one can make one detector look worse or better than another. I will also offer a suggestion when making comparisons that I think will make sense for those interested.

Now, if you watch the video you will see that the TDI also chirps but not as much as the SL. This chirp is more apparent when the operator was moving the coil up and down more and/or faster. Fortunately, or unfortunately, the chirp isn't nearly as strong on the SL.

Now, can a person take the same target and make one detector look worse than another? Yep it can be done, especially if the test target isn't a perfect shape. To prove this, you can test nuggets by changing the orientation with respect to the coil. In other words, on a flat nugget that has irregular contours front and back, it is possible to see a small difference simply by turning the nugget over. Better yet, take a flat nugget and turn it a little so the surface is not perfectly parallel to the coil and signals can change. Take a flat nugget and turn it edgewise and see what happens.

To alleviate this problem, one can purchase relatively cheap brass bearings or round balls and use them for test target. Brass does a really good job of mimicking gold targets. No matter how you turn a ball, the detector sees the same approximate surface area.

Next, try different sweep speeds when trying real world testing, where you bury a target and see what you can do to detect it. This sweep speed thing is important but is more obvious on the real small targets.

One thing not shown on the video listed but discussed on another forum was the SL appeared to fail when testing a certain coil. What happened was the detector seemed to whine forever and simply didn't work like it should. Well, if you read this or see a video about it, you will see it isn't a factory coil. What is happening is the SL doesn't work the same as the TDI (imagine that) and doesn't act the same when a coil is marginal for the delay setting.

Had the person who made this issue experimented just a little, he probably would have stumbled into the simple fix and that is turn the delay up just a little. Build a coil too large or one with too much inductance and there is a good chance it won't work right at the shortest delay. Again, just how the detector reacts to such a coil differs between the TDI and the SL.

Relic hunters often alter the delay to try to eliminate small junk. So, such a change in the delay eliminates any possible problem just mentioned.

So, my suggestion is this, if you own the SL or the TDI for that matter and you decide to purchase a larger coil, and that coil doesn't seem to act right or not work at all, try advancing the delay from the minimum 10 usec to maybe 15 usec and see if that helps. The not acting right takes a little experimenting to better understand because a coil may work but be noisy or generate odd signals if stopped quickly simply because of this problem. So, keep in mind a large coil that is just marginal can do some strange things that may act like the coil is bad. When in doubt, try turning the delay up at least 3 usec and see what happens.

Both the TDI and the SL can detect gold and ignore most nails and other larger trash, providing the gold is about 1/4 oz or less on the high purity gold. On the lesser purity, the size can increase a lot before gold will be ignored like the nails. In fact, I combined three 1/2oz nuggets by putting them in a plastic container and the three together still responded such that they sounded off with a high tone. This high tone normally indicates a smaller nugget and not the larger ones. However, in this case, the nuggets were rough and the gold purity was lower, so, the combination allowed one to ignore nails or other larger iron junk while still getting good signals on the larger gold objects.

The ferrous objects that will be detected will be pieces of nails or short pieces of wire, maybe boot tacks, or small pieces of tin cans to name a few. Now, keep in mind that there will always be exceptions, so one might get a signal or two from some larger object such as an odd nail that one might think should be ignored.

To ignore these nails requires the operator select the low conductor single tone mode. When this selection is made, any object that creates a low tone will be ignored.

Now, one can reverse the process and only try to detect very large pure gold and ignore a lot of the trash. This can be done by adjusting the GB and using the high conductor mode. Nuggets above maybe 3/8 oz or larger will usually give a reliable signal, providing the nugget is solid and the gold has high purity. The nuggets in the 1/4 oz to 3/8 oz can go either way, depending upon the nugget itself and the adjustment of the GB control.

Ghost town hunters or coin hunters can use this feature to ignore iron trash with a very high reliably while still detecting silver and copper coins.

What is nice is the TDI family of detectors can actually see through some of this iron junk (such as nails and wire) and detect nuggets under or nearby some types of trash. Just how well this can be done can vary because of the GB setting and/or the iron junk involved. As an example, nails may be ignored, but a full tin can won't be and can cause good objects near or under it to be ignored also.

So, fully understanding just how the TDI or SL works and how signals can be manipulated can make a big difference between success and failure.

Finally, there is a price differnce between the SL and the TDI, so one shouldn't expect the SL to react the same as the TDI. On the plus side, the SL costs less, is lighter, and quieter. These factors alone make a big difference to me.

One last note that has to do with the SL and something you might find on a video or a post on a different forum and that is the SL threshold is very smooth but seems to have a deadband, meaning there seems to be a dead space where a target can't be detected and this includes faint target signals. Well, remember what I said about setting the frequency control to minimize the noise? The worse the noise, the bigger this deadband can be. This deadband is telling you the noise is bad and being ignored. With practice you will be able to determine the deadband. Minimize the noise and you will minimize the deadband.

Well, that is enough for now.

Reg

Share this post


Link to post
Share on other sites

Hi Reg

That's some great Information, and as usual unbiased and to the point. It's always

good to see you post. Many of us can learn from your years of experiance and

knowlege of the inner workings of the tools of our hobby. I for one have benifited

from your willingness to share with those that have an open mind and want to learn

far more than an instruction manual will ever give.

I hope all is well with you and your family.

Best Regards

Herb (PVGOLD)

Share this post


Link to post
Share on other sites

Mariposa: I've posted you a couple of PM's, but you appear to be BLOCKED???? ausome

Share this post


Link to post
Share on other sites

Nice post Reg!

Rim

Share this post


Link to post
Share on other sites

There used to be a pinned discussion about what the tones tell you but I can't find it now, so I will post something here instead.

The tones are just part of what happens in a PI, whether it be a TDI or a ML. Filtering is another big issue that can cause strange things. Combine the two and one would be amazed at just what can happen to a perfectly good signal from a target.

On the Video in this thread, you heard one way signals. Now, at first glance you might think that one way response was telling you about the signal itself. In some cases that may be true but in this case, it isn't and similar responses occur on other detectors.

To prove my point, if you ever built the bucket that Patrick built that sort of simulated what was being done in the video, you can verify what I am saying now. That is, in the video present, the one way signal isn't because of a weak signal. If it was, then moving to the other side of the box and pushing the target through wouldn't cause a response until it was pulled back.

Well, in the video the target was always inserted from the closest side you need to watch again very carefully. I mentioned once the person slowed down the movement of the nugget it could be heard both ways. Also, he hesitated before he slowed down and left the nugget on the back side just a little longer before pulling it back. When he did this at about 3:42 or close to it, you will notice the signal wasn't there when he pushed the nugget in, but was there when he pulled the nugget back. Then the helper slowed down his movement and the nugget was heard both directions.

BTW, how many people noticed what I said in the last paragraph?

The fact that the nugget was ignored even going in tells me something else is going on, especially when the target is generating a reasonably strong response.

So, why does it matter what is going on? Simple, the target response is strong enough it shouldn't simply disappear and it certainly can't be caused by not being over the target, so what is happening? Well, on the TDI there is a blanking circuit that eliminates half the signal once it goes through a filter. The blanking circuit is eliminated half of a wee/woo or a woo/wee signal, leaving only the wee or woo, depending which happens first.

Now, what happens is the blanking circuit doesn't shut off perfectly and on strong enough signals can cause odd things to happen. SLoooooooooow down and the blanking circuit has the ability to settle down. Just as important is the fact that this blanking circuit can be triggered by noise. If that happens, brief signals which can happen especially on very weak targets could be missed.

On a ML, something somewhat similar can happen but it isn't the same. In this case, go over a visible piece of trash and you get a strong signal that can last for a very long time. Try it and you will see what I mean. Anyway, the strong response from the trash overwhelms a filter and the audio response can linger long enough that another deeper target can be missed because the stronger rsponse is still lingering.

The signal on a ML lingers much longer than that found on the TDI because of the filter design and associated circuitry. Now, on the later model ML's, there are different modes, timings, or whatever you want to call the different setting and in some cases the filtering is altered such that the recovery speed is made faster.

The point I am trying to make is one should listen very carefully to any and all changes even on the ML and I suspect you will be able to figure out a lot more about your detector than you know now.

On the TDI one can ignore iron if it is large enough if the proper adjustments are made. I strongly suspect something similar could be done once a person fully understands the different settings at their disposal. Anyway, it is something to think about and maybe try.

If I get my hands on one of the later models of ML I will try a few things with it, but because I don't know if I will ever hunt in AZ again and where I hunt in CO, the gold is usually too small for a PI, I probably will not buy even a used one just to see. Unfortunately, it takes time to figure out just what is happening or what might happen when settings change. Doing your best to take the time to try to see and listen what is happening just might help you with your selection of adjustments in the long run.

Now, for TDI owners, most never really take time to see what will or can happen. In many cases, they see something on a video or hear of a setting that worked for someone and they mimic it while not knowing fully why or what is happening.

The TDI is a simple machine to use but in some ways it is complicated to set up for the absolute best setting. Actually, complicated isn't the right word but because it takes time and understanding to better understand what is happening, it is the best word I can think of.

Actually, no detector is perfect or easy to use if one wants to get the most out of it. When in doubt stick with the recommended settings or the base settings, which ever works best for you. Don't expect the detector to teach you. Instead, you have to learn the detector and what it is telling you and why.

Regardless of the field of endeavor, those that become experts do so though extensive training, practice and hard work. Quite often failures are part of that learning experience.

So, in very simple language, learn your detector and practice a lot. Don't get fancy until you fully understand the basics.

Well, I hope I haven't bored you too much.

Reg

Share this post


Link to post
Share on other sites

Thanks Reg I'm also reading in on this.

BORED YOU SAY !!!!

How could anyone that has even a minute interest in detecting be bored ????

Every sentence you type is a learning experience for those of us who have never had the privilege of any formal education in electronics or "detector electronics" and I thank you for taking the time to chime in when you can. Hapy Huntn

Frank C.

Share this post


Link to post
Share on other sites

Thanks again for everyones help and advice. It looks like I'm going to be getting a Minelab GP3500 here within the next week or so. I'll let y'all know how everything goes! Thanks again!

Share this post


Link to post
Share on other sites

Excellent Reg! Glad to see you posting again.

I will add just one more note regarding the video. He has never mentioned it again to anyone since letting it slip to me last year. But the TDI Pro he is using in that video is not a stock machine. It has been "souped up" with a modification or two by him. I've no idea how it actually performs in the field but in the last year he's yet to find his first real nugget with it. So, listen to those who have actually found something! :brows:

Share this post


Link to post
Share on other sites

There used to be a pinned discussion about what the tones tell you but I can't find it now, so I will post something here instead.

The tones are just part of what happens in a PI, whether it be a TDI or a ML. Filtering is another big issue that can cause strange things. Combine the two and one would be amazed at just what can happen to a perfectly good signal from a target.

On the Video in this thread, you heard one way signals. Now, at first glance you might think that one way response was telling you about the signal itself. In some cases that may be true but in this case, it isn't and similar responses occur on other detectors.

To prove my point, if you ever built the bucket that Patrick built that sort of simulated what was being done in the video, you can verify what I am saying now. That is, in the video present, the one way signal isn't because of a weak signal. If it was, then moving to the other side of the box and pushing the target through wouldn't cause a response until it was pulled back.

Well, in the video the target was always inserted from the closest side you need to watch again very carefully. I mentioned once the person slowed down the movement of the nugget it could be heard both ways. Also, he hesitated before he slowed down and left the nugget on the back side just a little longer before pulling it back. When he did this at about 3:42 or close to it, you will notice the signal wasn't there when he pushed the nugget in, but was there when he pulled the nugget back. Then the helper slowed down his movement and the nugget was heard both directions.

BTW, how many people noticed what I said in the last paragraph?

The fact that the nugget was ignored even going in tells me something else is going on, especially when the target is generating a reasonably strong response.

So, why does it matter what is going on? Simple, the target response is strong enough it shouldn't simply disappear and it certainly can't be caused by not being over the target, so what is happening? Well, on the TDI there is a blanking circuit that eliminates half the signal once it goes through a filter. The blanking circuit is eliminated half of a wee/woo or a woo/wee signal, leaving only the wee or woo, depending which happens first.

Now, what happens is the blanking circuit doesn't shut off perfectly and on strong enough signals can cause odd things to happen. SLoooooooooow down and the blanking circuit has the ability to settle down. Just as important is the fact that this blanking circuit can be triggered by noise. If that happens, brief signals which can happen especially on very weak targets could be missed.

On a ML, something somewhat similar can happen but it isn't the same. In this case, go over a visible piece of trash and you get a strong signal that can last for a very long time. Try it and you will see what I mean. Anyway, the strong response from the trash overwhelms a filter and the audio response can linger long enough that another deeper target can be missed because the stronger rsponse is still lingering.

The signal on a ML lingers much longer than that found on the TDI because of the filter design and associated circuitry. Now, on the later model ML's, there are different modes, timings, or whatever you want to call the different setting and in some cases the filtering is altered such that the recovery speed is made faster.

The point I am trying to make is one should listen very carefully to any and all changes even on the ML and I suspect you will be able to figure out a lot more about your detector than you know now.

On the TDI one can ignore iron if it is large enough if the proper adjustments are made. I strongly suspect something similar could be done once a person fully understands the different settings at their disposal. Anyway, it is something to think about and maybe try.

If I get my hands on one of the later models of ML I will try a few things with it, but because I don't know if I will ever hunt in AZ again and where I hunt in CO, the gold is usually too small for a PI, I probably will not buy even a used one just to see. Unfortunately, it takes time to figure out just what is happening or what might happen when settings change. Doing your best to take the time to try to see and listen what is happening just might help you with your selection of adjustments in the long run.

Now, for TDI owners, most never really take time to see what will or can happen. In many cases, they see something on a video or hear of a setting that worked for someone and they mimic it while not knowing fully why or what is happening.

The TDI is a simple machine to use but in some ways it is complicated to set up for the absolute best setting. Actually, complicated isn't the right word but because it takes time and understanding to better understand what is happening, it is the best word I can think of.

Actually, no detector is perfect or easy to use if one wants to get the most out of it. When in doubt stick with the recommended settings or the base settings, which ever works best for you. Don't expect the detector to teach you. Instead, you have to learn the detector and what it is telling you and why.

Regardless of the field of endeavor, those that become experts do so though extensive training, practice and hard work. Quite often failures are part of that learning experience.

So, in very simple language, learn your detector and practice a lot. Don't get fancy until you fully understand the basics.

Well, I hope I haven't bored you too much.

Reg

That post is still around somewhere Reg.... Cant remember the title though :th:

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×