I suspect the two TDI owners that sold their units did so after only owning them a short while. As such, they didn’t know the tricks to make the detector hum. Worse, yet, they probably found a way to really make the TDI look bad. Yes, the more expensive units can go deeper, especially on a certain size gold. To make matters worse, if a person doesn’t know this or know just how the TDI works, or the best way to adjust the detector, then it is really easy to make the TDI look bad. So, it is easy to make a detector costing 3 to 4 times as much to look better.
It is easy to make the TDI easily ignore gold sitting right on the surface. It is easy to adjust the TDI so it is too noisy. It is easy to tweak one of the controls and lose over half the maximum depth on certain objects with a simple twist of a knob.
On a different note, it is easy to hunt areas with the TDI that cause other PI owners to quit. On one of my last trips to AZ I had a guy inform me he could hunt in the middle of Octave with his ML just as easy as I could with my TDI, but after less than an hour, he was done. I hunted the trashiest locations with ease and only dug a few pieces of junk. Unfortunately, I ended up with only one Barber dime and a handful of other non ferrous stuff for my efforts but it was fun.
Now, I loaned my TDI to Tony Pancake on one of my last trips down to AZ and we hunted Octave again. During that time, all he could say during the hours we spent hunting in the middle of that trash can called Octave was how great the TDI was and easy it was to tell the iron junk from good targets. BTW, his ML sat in the back of the vehicle.
What was the difference between Tony and the guys who owned a TDI for a few days? Well Tony has owned different ML’s and knew the quirks of them as well as how a PI works. He knew what to expect and the basics of a PI. So, for him it was a simple fast track with a little help from me to get a good handle on the TDI and he was off hunting right in the middle of Octave amongst the cans and other junk and all the while finding even new tricks to use to eliminate digging or recognizing the junk. During those few days he used the TDI, all he could do was yell over to me letting me know what he liked about the detector and another new trick he found to use. Oh yeah, Tony was given the knowledge of a few tricks on what to expect if the TDI was adjusted a certain way.
Now, there is no doubt that the ML will go deeper, especially under the right conditions and even Tony knew that. Change conditions and locations and things can change. Besides being able to minimize digging trash in the trashy areas, it was easy to walk directly under power lines with a mono coil and not have to worry about readjusting the detector. At the end of that trip Tony was pleading with me to leave the TDI with him for a while.
Personally, I can take a TDI to a park, hunt for a couple of hours and basically dig nothing but older silver and copper coins while not digging trash of any sort. The nice part is, I don’t even hear the trash signals. I can then go to a ghost town and do the same thing. Hunting meteorites is a piece of cake with a TDI and again, I can ignore much of the trash. When time and location is available, I can hunt gold, both large and small in about any area including some of the trashiest locations available, while again, not digging much if any trash.
I can target small gold or large gold, depending upon what I want to do while ignoring a lot of other things including much of the trash of the area. Unfortunately, I can’t tell lead from gold, but I can tell basalt from the good stuff, which as you probably know is to be found in many gold locations including around Octave.
I can easily find a half oz nugget in the middle of a nail ladened area and not dig or even hear a signal from a nail. I can also search the same area with a little different setup and find the smaller nuggets in the few grams or less and still not hear or dig nails. Again, it is because of knowing how to adjust the detector and how it works.
I can make a Rich Hill 1/4 oz nugget depth of detection go from a few inches to as much as 2 to 3 times more depth just by knowing how to tweak the machine. Unfortunately, this is the down side that most new owners don’t know or understand. BTW, this same condition exists on the SD’s also.
At Model Creek, we found a bunch of nice larger nuggets many of which were a half oz or more. Now, at Model, I could hunt those same nuggets and again, ignore nails and most thicker iron junk and still detect nuggets from a few grain in size to larger than a half oz or more without making any changes to the detector.
Is the TDI perfect? Nope, in fact it is far from it. Do I have to make more adjustments to maximize the use of the TDI? Yep, but a quick twist of a knob and I know what to expect and how to pass over a nail or even a full size tin can and not hear a peep. I can get a strong signal from either with nothing more than applying a few tricks or a minor adjustment. So, I can make the TDI look like a unique PI or one that clearly doesn’t go as deep as some others.
Would I trade the tricks I can do with the TDI for shear depth I might get with a different PI? Not in a million years. Today, much of the gold left is hidden in the areas where others fear to tread, simply because of all the trash. Those places are open to me and I don’t have to worry about digging everything to find what little gold is left. Will I miss some? Yep, but so will those who get frustrated after digging a ton of nails and nothing else to show for it.
Part of the fun of owning the TDI is the ease of building a new coil. Find a housing that meets your needs and as long as you can count the number of turns and have basic soldering skills, and one can build their own designed coils. The beauty is, they will work even if one screws up a little. No, you may not be able to operate at the shortest delay, but close to it.
Want a 3′ square coil to hunt large meteorites? How about a 2′ by 5′ one that you can drag behind your ATV and still work fine? Maybe you want a “Clean Sweep” type coil that is long and narrow you can use to quickly hunt a fairly large path each sweep but still be able to poke it under brush. The trick is you can build your own with relative ease once you know the basics. If you don’t want to build your own, well, others are now building different sizes of coils and the price is surprisingly quite low.
Own one of the first 200 units, and it is easy to make that detector detect smaller gold. However, this trick should be left to those who know how to make the right changes.
Now, with all that said above, I don’t recommend a TDI to just anyone. Many new owners will not learn all the tricks over night, in a week, or even in a month or two. However, those truly interested in wanting a specialized PI can learn enough in a day or two to do quite well, just like Tony did. The trick is to adapt to the TDI and not try to make the TDI adapt to you. Written by Reg Sniff
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