One should keep in mind that the TDI is not for everyone and it does take time to learn. One can't expect to go out in their back yard, spend an hour or two and know how to work it. It simply doesn't work that way. There is a learning curve that has to be overcome, plus a person should learn just what each control is doing and why it is adjusted. This isn't hard, but does take time to do. Without such knowledge it is very difficult to know just what to do if things are not going as planned.

One more note, I need to check just how the elliptical coil works in all modes and under all conditions. I suspect the elliptical coil will react a little differently and may alter just how the signals sound. The only way I will know for sure is to try it when mine gets here.

The TDI works great for coins. I have personally found over 100 older coins with mine in a park in town that has been beat to death by other detector owners. The discrimination works extremely well once you know how to set it up. In fact, I normally will not dig any trash at all during my coin hunting outings. BTW, set the detector up for coins and then hunt the Rich Hill area for gold bigger 1/4 oz or bigger and you can ignore, yes, ignore all iron including tin cans. Actually, I am not sure just how small of gold it will find while doing that, but I do know that 1/4 oz nuggets and larger will be detected. I have personally walked through the trashiest part of the ghost town Octave and picked out several non ferrous items including one old coin while basically recognizing and/or ignoring the iron junk including the cans and pieces of cans. Large cans do require the coil be raised to fully test the disc feature, but generally, most of the junk is simply ignored and produces no signal.

Then, if you want to hunt small gold, you can set the detector to ignore most ferrous junk and hunt away. Much of the ferrous junk will again be ignored. Small pieces of cans will be detected, but using a couple of tricks and one can determine that type of junk with very high reliablility so one can just about walk by most of that junk also.

Then of course, the TDI can be set to hunt all sizes gold at the same time and still able to recognize much of the iron junk. So, in simple terms, the TDI works great for nuggets and really does well for relics. Now, that combination is hard to beat when you think that the TDI doesn't suffer from electrical noise anywhere like some other PI's do.

You mentioned one should buy a ML, well that is fine, they do work well in most places. Try working under power lines and you may have a problem. There are also places where the emi noises makes things extremely difficult to overcome.

So far, I have not had any of those problems with the TDI. The design is such that it minimizes such problems. Yes, the TDI does have less overall sensitivity and as such the reduced sensitivity allows it to be used about everywhere.

Oh yeah, I do have an SD, but considering the TDI weighs far less, gets about the same depth on smaller gold, the type we find here in the US, plus allows me to ignore most ferrous junk, I prefer to use the TDI.

Now, I doubt you have used one, but that is fine. There are a lot of people who will not want to use one let alone own one. However, before condemning a detector, you really should spend some time with it and find out what it can do. No, it will not compete directly with the 4500, but it holds its own against some of the other models. Now, anyone who tries to compare the $1500 TDI to a $5000 GPX is not even using common sense.

The trick to using the TDI is knowing how to set it up. It does have some features that allow for a wide range of different hunting conditions, so it can be set up to look bad if one wants to try hard enough. BTW, with a tweak or two that takes less than 5 minutes to do and that includes taking the unit apart and the original 200 TDI's built can be adjusted to detect gold too difficult for even the higher priced 4500's to detect. I know this is true because I have done it.

As I said, the TDI is extremely versatile and can be adjusted to do a lot of different things, some of which conflict with nugget hunting. As an example, a good PI will also detect small foil just like it is a nugget. Now, that can be a problem when coin hunting, so with a simple adjustment, the foil can be ignored. Make this same adjustment when nugget hunting and yes, you will ignore small gold too. Fortunately, the TDI was built to be used by someone with a little common sense and as such, such people won't make the wrong adjustments when gold hunting.

The common sense is required and some knowledge of the controls are required to take advantage of the abilities of the TDI to be able to recognize most ferrous junk. So, it does take a while to fully learn the detector so you can appreciate just what the detector can do.

So, the TDI is far more versatile than a basic PI, but it is not for everyone. Common sense, a little patience and the willingness to learn are the requirements to maximize the features of the TDI. Obviously, there are people who want more of a turn on and go detector and could care less about the ability to discriminate junk or think they will miss something.

Keep in mind, there is nothing out there that acts the same or uses the same techniques so it is something new to learn. The TDI has the ability to distinguish ferrous junk even when using a mono coil as well as the DD type.

Just my two cents on the issue.
Reg

This post was re-published with permission of the author. The original post was on the Arizona Outback forum

Updated TDI review information:

Hi Bob,

I probably shouldn't have mentioned the 5 minute adjustment because it is an internal adjustment that should only be done by someone completely familiar with the design. There are a lot of internal adjustments and only the one that adjusts the minimum delay will help. Adjusting any of the others will most likely cause the detector to fail to work, so no one should attempt this except an authorized repair shop or Whites themselves.

I would expect it would be extremely expensive to have the detector recalibrated, or even repaired if something were done incorrectly. So, it is not something that should be tried.

As such, I am sorry I even mentioned it and that paragraph probably should be removed.

So, you might pass this info to the guy who asked the question and explain to him it is something that will probably be done after the warranty is over and can only be done on one of the first units designed. Later versions using a different internal pc board don't even have the control, so it can't be done anyway. Once again, it is not something a person should try by themselves.

It's recommend people visit the Whites TDI Tech forum for more TDI information. Here is a link to that forum;

http://tdi.invisionplus.net/index.php?mfor...amp;showforum=3

Thanks,

Reg

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