Robby_H

Allan. Westersten "If a void produces a negative signal and a nugget produces a positive signal, should we be worried about a response to voids"? Yes, or no, Mr. Detractor? Do you have the balls Mr Detractor to have a debate with Allan on GPoz are you going to wimp out yet again? all the best to you folk, doug Doug, does he, or does he not, disclose a Minelab thumping method to cancel the ground? A simple yes or no will suffice. If the answer is no then there is nothing to debate and if he doesn't display a good understanding of the "viscousity" signal and our ground problems and how our ground behaves then there is also nothing to debate. I'm still trying to get over his method of comparing fields strengths.

Doug, does he or does he not have a Minelab thumping method to cancel the ground? A simple yes or no will suffice. "I am certainly not going to continue to post here when the folk best able to answer all the questions on these new detectors are on Gpoz". Oh if only this was true!!!

And Doug, You appear to be hung up on the term "universally cancel". This refers to being able to null the signal from a particular substance at one setting regardless of the quantity, shape or orientation, it doesn't mean being able to cancel multiple ground types simultaneously, eg, Poole gives an example where he cancels the response from a steel block but the method obviously doesn't universally cancel all steel objects and his method doesn't universally cancel wet sea side sand or sea water. It would need to be adjusted if the volume of the sand or water surrounding the coil changes. Get It? To the QED, you say you can run 5 timings sequentially (you obviously mean 5 different pulse lengths and associated timings) with a coil travel of 100mm but a Minelab pi detector runs two different pulse lengths and transmits a train of 4-5 pulses and makes an analysis in less than 1mm!! If Minelab were silly enough to transmit the train of pulse lengths Bugwhiskers proposes then they could do so in 1.3mm or 1.3 milliseconds versus your 100mm. Why would you transmit 5 different pulse lengths anyway?? Some kind of weird science or just something to impress the gullible? It was only suggested on your forum the other day and it is now headline news! Perhaps it needs more thought? Why make these big claims, especially when you haven't perfected one timing yet? You say you have but this was when using unusually low gains. Perhaps you should try it again when using the higher gains you are now using on the bench or when using sufficient gains to beat a ML pi on hot variable ground? This will also test your claim that you can sample earlier than Minelab when using a relatively long pulse on hot ground. It is also silly to claim your SMR is efficient when the QED video shows a real problem that will raise its head if you have to raise the gains more to compete with ML. Your current air depth tests mean nothing so please don't mention them. How would the average Joe know how to devise his own timings? Do you know anyone who has ever fitted "better" timings to a Minelab pi detector? Plenty have tried but none have beaten the factory timings without a noticeable downside and yet you seem to be saying your Minelab thumping GB or ground/target separation can be improved by the average user? BTW, one of the guys on your forum who performs mods on his own 2000 said, "The other thing that I have noted time and time again is the depth loss on bigger nuggets 1gram and up when running the higher frequencies". I have pointed out the reasons for this depth loss before, ie, this mod dramatically lowers the peak coil current. So don't you think you should pull Woody up when he says his high frequency mod blows a 4500 away? It gets even worse if you have read the Sept edition of GG&T. Woody says, "Ohm's law states that 6 volts flowing into a coil with a resistance of 0.5 ohms will create a current draw of 12 amps peak"!!!!!!! Peak coil current is dependant on other factors so how the heck can he use Ohm's law to calculate it??? And you say, "Other than the great Geotech forum and perhaps Eric Fosters forum Gpoz has without doubt the best collection of electronically and electromagnetically credible, innovative and very clever detector designers". lol.

I see you are at it again Doug! "Inhere , perhaps you can tell all the folk here about Pi Gb systems eg Give us your insights into the Poole and Eric Foster methods compared to those used by ML". Why would anyone comment on this when you don't understand the obvious differences and probably never will? "The MPI, and the USA Goldsweeper are definitely going to market and sooner rather than later". The original Goldsweeper page... http://www.dienco.com/ Prototype completed in 6/10/2000 and due to be released 6 months after the FAQ was written? So nine years. Do you reckon we will see it in ten? Do you believe it will arrive at Xmas and which Xmas? Remember the PD was coming soon several years ago? The three you mention aren't cutting edge technology until proven. There are a stack of patents for metal detectors and these range from downright dumb to brilliant but you are patrolling the net saying an inventor's claims are valid simply because he is a member of your forum and says naughty things about Minelab. We would all like to be able to discriminate but the detector must first hear the target to do so!! When we use a good ground cancelling detector we listen for the faint signal from a nugget at depth but we wouldn't be able to hear this signal if the ground wasn't cancelled so I think we would all agree that efficient ground/target separation must come before discrimination. One of the "cutting edge" detectors you mentioned takes two samples during the pulse off period. One to first "hear" a potential target in order to trigger the discriminator circuit and another to supposedly calculate the target's time constant (lol) but it doesn't say how it separates the feeble "trigger" signal from a nugget at depth from our overwhelming ground signal during the off period. The only thing we are interested in here is if it offers something better than Minelab's method to cancel the ground but the patent doesn't disclose a magic bullet or anything to address our ground problems at all!! Your mate Alluvium even said GB is everything in our Oz ground and he is correct!!! There is some mention that I have fallen into a trap but as long as you and Buggsy spread the myth that ground cancelling isn’t rocket science and these naïve guys believe you then Minelab have nothing to fear. The inventor has made statements that aren't quite correct. He says conductive ground is unlikely to vary during one sweep but a damp mineralised salt lake will often give several target like responses per sweep and for obvious reasons. The "viscous" signal definitely doesn't behave as he says either and a sample of ground from Beggery won't help him much. The mutual inductance signal is still contaminated at the end of the pulse. The method he suggests to compare detector field strengths is the real killer!!! He said, "To avoid being humiliated by a Vapour Detector, the yet unnamed succesor to the GPX-4500 must beam sufficient power beyond 50" to light an LED". The statement in itself is self-humiliating!!! Draw the equivalent circuit. What do you see, what actually lights the led and what can influence the result? It is very obvious that the poorest performing pi could easily light the led at the greatest distance!!!! If you can’t see this then take a few minutes to knock up his test coil and circuit and you will see just how truly absurd this is. And you expect me to have a debate with this guy? Would it be any different to the PD episode? There are more but he is the guy making the large premature claims and besides, he will be sending one over to Oz for testing "sooner than later".

Doug, SETA has nothing to do with Ferrites. It is a truly novel way of cancelling static fields for a large number of timings without needing a bunch of cmos switches and trim pots and factory adjustments for each timing. In theory, the number of timings could be almost infinite. SETA requires a processor to work and this is much more complex than anything you have planned for the QED. If you have read and can understand the patent then you would also see that it would be very silly to allow anyone to perform mods on a 4500. You are supposed to be an ex-scientist and yet you can't, or refuse to read the patents and jump to conclusions if it suits your obsessive anti Minelab agenda. Large coils warp more than small coils when they are abruptly tilted because of the much larger force exerted at the lugs, so you should at least check this before jumping to conclusions by removing the coil and tilting it by hand well away from the ground or metal objects, ensuring it is suitably supported and the cable can't influence the result. The trend towards making coils lighter can also make some coils more prone to flexing. Heck Doug some large coils require the operator to side step with the swing and use a slightly circular motion at the end of each swing! Qld Sandy is correct re mildly conducting soils causing more problems for large monos and you will be faced with the same problems with the QED if you can first solve other generally unknown problems you will surely encounter. You would actually know this if you had conducted tests or even seen JP's videos. The ground Sandy is talking about can be average ground found anywhere but is often worse in the diggings and lower slopes and gullies and in sink pockets. The latter usually sounds exactly like a symmetrical metal target. You can often pick this ground by the way the coil responds when tilted because a sensitive pi can't universally cancel the varying volume of mildly conducting material under the coil and still remain sensitive and is thus prone to changes in orientation and increased coil size. BTW, BW will eventually understand what is meant by universal cancellation if he is actually using a gain of 16,000,000 (cough) and he might even perhaps understand what he is seeing when looking at the Enhance timings oscillogram on your site. You say it is appalling that a viewer can't tell which coil is the best in your two oscillograms on the other thread but why would the average user be expected to know which is best, especially without knowing what he is looking at or if the damping is constant in each case? I could easily form an argument favouring the old coil Without more info and would also assume you have a circuit problem when looking at the newer coil's waveform. I bet BW had to explain the oscillograms to you so why dump them here without a thorough explanation? You whinge about supposed problems with static field cancellation and yet you are very cautious in your comments re the video on this link. The only detector actually shown sweeping across the ground when approaching a supposed target is the unmodified 3000 and the ground is obviously very quiet!!!! It appears to give a response on the first sweep and nothing thereafter, which suggests the target was a hot rock and it tracked out. If so then why didn't the modified detector track it out? I think I know after seeing what Woody does to the front end of these detectors! We never see the modified detector being swept over the ground when approaching a target and the operator has trouble developing the signal even though he supposedly found each target with this machine, and notice the excessive noise when the coil is tilted or in motion over the supposed target? Why were both mods switched in when the average Joe would demonstrate each individually? Why didn't he compare the ground cancelling ability over say a marked 20' section of ground? Why wasn't the same coil used on each detector? Why didn't he conduct a static field test?? Did you conduct a static field test on the modified 2000 which supposedly saw your infamous aluminium block deeper than any other model at your test site? Common sense also tells us that the high frequency mod results in a proportionate large reduction in coil current so why doesn't woody advertise this along with the obvious fact that this leads to a reduction in sensitivity to nuggets already detectable with a stock model? Eg, if we double the frequency then we almost halve the peak coil current!!!! You knock ML but appear to condone this very misleading practice! Really Doug, your obvious bias and lack of understanding makes you a very poor source of accurate information. You should at least try to keep abreast of new technology otherwise you will be simply seen as a stone age man trying to tell Einstein he got it all wrong and you should keep these discussions on your forum where a few actually believe some of this stuff. The patent parrot.

http://206.188.2.79/products/manuals/SD2200.pdf