Re: White's TDI Pro in Silver Country [including Infinium Comparison]
Hi 63bkpker,
Both these units are very good at what they were designed to do. The TDI Pro was primarily designed for gold nugget hunting and I have no doubt that it does very well at that task.
What About Iron…
I tend to use the TDI Pro for specific tasks in this application, for example in high nail infested areas, operating in the low conductive tone mode to capture low conductive silver ores while eliminating most nail signals. Silver hunting is a different ballgame from gold hunting insofar as silver normally comes in much larger sizes and signals similar to larger iron…these are easily confused…particularly at depth. Compact large iron presents quite a challenge in this regard whereas either unit is capable of identifying large elongated iron including nails as described in the report. Neither unit can differentiate small low conductive iron from low conductive silver signals.
The Infinium with its automated tones is quick and effective at differentiating elongated iron including nails from silver ores, and in zero discrimination will indicate compact iron such as drillbits, larger milling balls and other non-descript ‘chunky’ iron with a lo-hi tone. Only silver with conductivity at or above fringe zinc penny level will respond similarly and they are an infrequent occurrence. So we have a solid indication that the target is most likely iron and we can choose to ignore it at the risk of ignoring infrequently encountered high conductive silver. We can play the odds and those odds are overwhelmingly in our favor. By contrast…we can choose to check that target in reverse discrimination. If the signal changes to a hi-lo signal AND the signal volume undergoes a serious reduction… we can choose to dig it to avoid the possibility of losing any silver…its your choice based on useful indicative information. Most compact iron as described will change over to a hi-lo signal in reverse discrimination but it tends to retain most of its signal volume… and such iron is mostly what we encounter digging those signals.
By comparison the TDI Pro is not effective at indicating the identity of compact iron. Sometimes with time-consuming GB control adjustments we can obtain a lo-hi-lo definitive iron tone but mostly that is not the case and we have to dig such signals. By and large it’s a waste of time. Secondly…in the low conductive tone mode the TDI Pro will ignore most nails but it does frequently signal over larger elongated iron such as spikes and drillrods with either a good positive signal or a rather spurious signal…in part depending on the coil sweep direction. Now these can be readily identified with a lo-hi-lo tone and often without adjusting the GB control. But it means flipping the toggle into the all-conductive tone mode and sometimes adjusting the GB control to recheck such signals. This takes additional time that adds up over the course of each day. The result of the above is that I can cover much more ground with the Infinium’s automated tones and do so more effectively by avoiding unnecessary digging in tough rocky substrates. So in this respect for general searching my strong preference is the Infinium and no mistake about it.
Depth / Sensitivity
Operated at bare thresholds the TDI Pro is a noticeably deeperseeking and more sensitive unit. The Infinium’s depth / sens is improved by adjusting the threshold control up to 6ish or slightly more and adjusting headphone volume to preference. With this adjustment to Infinium…I see little or no difference between these units regarding depth / sensitivity over a variety of targets buried at variable depths in my testplot. There is some variability between different types and sizes of coils of course…we see that large coils tend to be deeperseeking on larger targets and less sensitive to shallower small stuff and vice-versa for small coils. Mono coils give better depth / sens results compared to similar size DD coils here.
With that said, lets look at
low conductive target responses presented in the chart below. The majority of silver ores are low conductive. Keep in mind these depths do not represent the full capability of these units. Solid lead “nuggets” have been added to my testplot since posting the TDI Pro report. Using lead “nuggets” instead of gold or silver nuggets, the fact that they’re freshly buried, and local EMI conditions… all contrive to reduce detection depth compared to naturally settled gold or silver nuggets in the field. But they do work just fine for relative side-by-side depth comparisons between units. For this comparison, Infinium threshold is set to slightly above “6”… at zero discrimination, with the GB locked. The TDI Pro is set to proper ground balance at GB9, maximum gain, and a bare threshold. The chart designations indicate
Weak,
Fair, and
Good signal responses.
I tend to compare the 8” Infinium round mono to the Razorback 5 X 10” elliptical mono, and the Infinium 14” elliptical mono to the 12” DF round stock coil because these are comparable sizes and seem to give the best results overall. I think we can agree that the results are fairly close…the variances are likely due to the coils tested. I see no advantage either way on these low conductive targets.
Lets look at the next substantial group of silver ores…
the higher conductives in the chart below… a comparison between an Infinium 14” mono and TDI Pro 12” DF coil. Compare the red TDI Pro depths at GB9 to Infinium’s depth results at a threshold setting T = 6. The TDI Pro test results indicate that the pulltab to screwcap conductive range is more susceptible to depth loss compared to Infinium with both units properly ground-balanced here. Based on these results, I prefer the Infinium for this application.
The Infinium is simple to operate, is weatherproof, and uses readily available “AA” batteries…especially handy for extended backpacking trips. The TDI Pro compared to Infinium at a bare threshold is more sensitive and deeperseeking. It is more flexible as to how it can be used, has a sturdier stem, is lighter on my arm, and has a much better coil selection. For comparatively small, mostly low conductive gold or even coin hunting where separating large iron is much less of an issue… the TDI Pro would be my preference. But…I wouldn’t hesitate to use the Infinium with the 8” mono coil and increased threshold setting. That was a good question and thanks…best of luck with your trip this season.
Jim.
, WOW......that sounds fantastic & you have had the time of your life by the sounds of it. Cant wait for your write up....& photos. 101 lbs....how on earth did you manage to lug that out without a helicopter?? 
, i still haven't picked up another machine yet and only had my fathers XLT out once this summer, busy playing on the water, but i must admit the bug is setting in again.
