Re: Minelab experts, Is the new White's TDI an attempt to compete with the E trac?
The TDI was designed as a nugget/relic machine after the GS5. It is a PI which has no TID or tones. It is not for everyone .If you are just a coin shooter in mild ground the Explorer models would be the better choice. If you are in mineralized ground which you are not (Indiana) the TDI would be something to consider.
Years ago GS5 users discovered a unique coin setting which is present on the TDI. The technique is not on any video yet and until recently was only known to a handfull of operators. I actually feel the GS5 is superior to any VLF in recognition of iron. It can tell the difference between an iron bar and a gold bar for example.
Reg Sniff made an excellent post about the TDI and coin hunting which is below. His quote" Anyway, the net result was I only dug 3 targets I was relatively sure were coins and they were a 1919 penny, a 1918 penny and a 1891 penny." illustrates the effectiveness of the TDI for coins.
His park had been hunted to death by hundreds of VLF users, however the park was heavily mineralized. He has been regularly taking out silver and copper from this old hunted out park. PIs have greater depth than VLFs in mineralized ground so that is why the TDI could detect coins here which VLFs could not see. So parks and areas which have heavy minerlization is where the TDI would shine.
Hi All,
Recently I posted how to minimize digging nails while coin hunting in a park with a TDI, and was questioned about just how I knew. So, today I decided to see just how accurate I could be. The park where I hunted is heavily mineralized and sits above the Arkansas River in Southern Colorado. It is about 100 years old, so there is always the potential for finding older coins.
Well, this park has been hunted to death and has been pretty stingy about giving up any older coins until I began using the GS 5 that I modified and added a unique feature which ultimately became known as the single tone mode. Having the very first PI with this ability was kind of neat, but I felt the need to share the technical aspects. I personally thought this feature was too big to not be installed on both the TDI and the GS 5. Ultimately, this new mode was added the both the the detectors.
So, how well does this mode really work when trying to find coins such as silver and copper coins? That is what I wanted to verify today using my latest techniques. I say techniques because now I hunt with a delay of 10 usec, the GB set at about 9 and the conductivity mode switch to high. With this setting, both high conductor coins and many nails will generate a nice distinct response. The trick is to know which are which if one wants to minimize digging nails.
Can that be done? Can one basically separate nails from coins? Yep. Now, this is not to say that I don't pass up a few coins that act strangely, because I am sure that happens, but today is quite typical of what I normally end up digging and my expectations.
Today's hunting time frame wasn't that long, maybe 45 minutes or so, but it was enough to prove a point. At the end of the 45 minutes, my success rate of actually guessing targets was 100%. I also dug a few suspected targets I knew were not coins but I thought were not nails either though they generated decent signals at the normal setting. They needed further investigation which requires a second test, and that test is to reduce the GB setting..
Also, I didn't bother with surface coins because that was not my objective. With a little experience a person will be able to easily separate the strong response from a surface coin from the mellow tone of the deeper ones. Anyway, the net result was I only dug 3 targets I was relatively sure were coins and they were a 1919 penny, a 1918 penny and a 1891 penny. Two targets I was not sure of but didn't think were coins or nails were what looks like a copper cufflink and a larger piece of lead. These two objects did pass both tests, but still didn't sound like nice smooth coin size signals.
Finally, I had 3 signals that sounded just like coins at the initial setting but clearly didn't pass the second GB setting test, where I reduced the GB to about 5 1/2 and listened to the signal again. Coins will still give that nice mellow response at the lower GB setting, but nails will really stutter or the signal will simply disappear. This last three nail type signals turned out to be just that, nails. I intentionally dug them only to verify my suspicions.
There were probably 6 or maybe 7 other targets that gave a nice signal at the original settings, but were too wide of a response, or clearly generated a double blip, more commonly associated with nail type objects. So, these were not dug and were not added to the result per se.
Anyway, the TDI was not designed to be a coin hunting detector, but I can say from experience it does very well in this field. The key is to simply learn the signals of a deep coin and be willing to adjust the GB control and check again. The technique isn't difficult but the success rate will increase with experience. The biggest mistake is to try to make a good signal out of a bad one.
There will always be a few false signals which are normally intermittent type signals that do not repeat with any consistency, if at all. So, the TDI is not the perfect coin hunting detector, but is a very deep seeking one, that with a little knowledge and experience is an exceptionally good one, especially in bad ground.
Anyways, this is my take on the issue.
Reg
George
