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Geotech last won the day on December 9 2016

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  1. Yes, nuggets often have multi-domain eddy responses.
  2. Both polar and cartesian plots can have XY axes, what they represent depends on what they represent. Technically, for a metal detector they should be the IQ axes, for the "in-phase" and "quadrature" signals. Sometimes they are called the XR axes, for reactive (X) and resistive (R). Sometimes the ferrite is on the left, sometimes on the right, and sometimes at the 12 o'clock position, depending n the preference of the engineer. Yes, kind of. Bent and twisted metal ends up having eddy responses with different phase angles (the metal thickness appears to vary), so the response is not homogeneous. A bent nail, or can slaw, are good examples. Jewelry can also be all over the place.
  3. Deus looks to be the same as V3, maybe a little more real time. The V3 attempts to plot a single sweep over the target, which is hard to figure out without a motion sensor in the coil. A perfectly straight tight line represents a strong single-domain eddy response. The tilt of the line is the raw phase. Close to 3 o'clock (180°) is high silver; 2 o'clock might be copper cent; 1 o'clock nickel; 12 o'clock would be salt; between 9 and 12 o'clock is iron; 9 o'clock (0°) is pure ferrite. The distance from any point on the line to the origin is the signal strength. Yes, this is a simple vector response. Most (all?) detectors map the raw phase (0-180°) into a VDI range (i.e. 0-100); there is no standard for this. As the response balloons out into a tilted ellipse, the ballooning represents a changing phase as the coil sweeps over. Often this is simply due to a weak signal. So you can read the tightness of the response as a confidence level. The wild responses can be due to 2 things: multi-domain eddy responses, as in the silver chains; and combined magnetic & eddy responses, as with the bottle caps. As a bottle cap enters the coil field it initially looks ferrous due to the iron content. As it goes past the center of the coil the eddy response of the flat steel dominates and so the phase at the peak amplitude of the response looks non-ferrous. Many detectors report target VDI as read at the signal peak, which is why bottle caps fool them. With the XY plot you can visually see the whole response, so bottle caps become easy to discern.
  4. X=reactive and Y=resistive; together they give you the phase. So for a straight line response, the angle of the line is the phase, and the length of the line is the amplitude.
  5. This excuse is greatly overused by companies. Custom & semi-custom parts (keypad, display, etc) and sole-source parts, yes. But most electronic parts are either multi-sourced, or easily substituted with something close enough. The actual reality is, most companies (and not just detector companies) don't repair at the component level, they repair at the board level. That is, they swap out a whole board. When a product is discontinued, they normally set aside a stock of replacement boards sufficient for x-years of repair. Once those boards are gone, no more repair.
  6. That was pointed out by customers over & over on the Prizms. Before I left, the MX Sport package had reached proto stage, and I tried to convince mgmt that the h/p jack was on the wrong side, and why. I think my effort actually persuaded them to leave it where it was. In a nutshell, that's why there were so many missed opportunities.
  7. The wireless pinpointer connect was something that the White's TRX had designed into it, but it was never implemented. I even filed a patent application on the technique about 4 years ago. Because the V3 wireless module was going obsolete, everything was designed around a new module that was supposed to have debuted with the first new 'Sport design. The pinpointer would tell the detector to disable its transmitter, and pinpointer audio would be sent to the headphones. Since the TRX is a full VLF design, it could even send VDI info to be displayed on the detector screen. User setting changes could be made from the detector or a cell phone app. However, White's mgmt didn't think much of the idea from the beginning*, it was entirely driven by Engineering. After I left they let the patent app expire, and apparently even wireless audio got dropped from the MX Sport. As far as I know, the socket for the wireless module is still being put in the TRX. It was intended that early pinpointers could easily be upgraded to wireless, I'm guessing something that will never happen. - Carl * The verbatim quote: "I don't like that idea at all." That was the day I first asked myself, "Why am I here?"
  8. It works, I've done it. The ink used in paper money has iron in it, any good BFO will detect it but only an inch or so away.
  9. The short answer is no. And no. And no. And no. A patent forbids you from even making a personal device that infringes, with one exception: you can build the device for the purpose of evaluating the patent claims. If you build a device for normal use, that's infringement whether you sell it or not. If you build a device and give it to someone else to use, you both are infringing. If you sell a kit that, when built, infringes, then you are guilty of inducement to infringe. Etc etc.
  10. From 2012, Carl's 7 rules of PUD: For those with the dream of being a one-man metal detector manufacturing company, post #129 suggests: Here's a challenge for you... build a production run of 20 units. Just 20! See how long it takes you. See how much money it costs you. Keep very accurate records. Figure in labor, overhead, taxes, marketing, and eventual service. Then see how much you need to charge for those detectors to make it worth your while. Those 20 units shoulda been ready to ship upon announcement.
  11. If I don't get back within a year, then a follow-up is probably in order. Send me your email, I'll set you up right away.
  12. All ya have to do is read the "Can't Register?" post. It tells you why, and how.
  13. Yep, Geotech ain't much different than the rest of the internet, but it is interesting. Lots of good ideas pop up from time to time, very few ever get developed into something usable. A lot of the guys don't have the complete know-how, or don't have the time, to get it to the end. This feeds back into MD's "kickstarter" thread, where the kind of people needed to turn a metal detector idea into a metal detector are people who have done it before and know all the nuances and gotchas of what it takes to get to the end. The people who say they can do it are plentiful, the people who can do it are exceptionally rare. As for Funfinder's thread, I think his frustration is that people on Geotech have been build plain ol' PI detectors for, what, 16 years now? And there doesn't seem to be much forward progress in what they've done. I would agree with that. I think he'd like to see more VLF and multifrequency developments. But, compared to PI, those are really hard for DIY folks, so most of them stick with simple PI circuits. I get his frustration.
  14. I'm gonna see if mgmt will allow a better tour video. Certainly there are some things that we don't want to show, but there is a lot of impressive stuff in the factory that is not sensitive. Having worked at White's and toured Garrett & Tesoro, I can say that FTP easily has the most advanced factory in the business, and probably the biggest.