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Detector Prospector Magazine

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Everything posted by PimentoUK

  1. "Is pure nickel sometimes used in inexpensive jewelry? " I think it's more likely to be nickel-plated, probably with a decent thickness, and the underlying metal is brass or bronze. If the plating is substantial enough, a magnet will be attracted to it.
  2. "Segments and tones just lump the ID ranges together? " Broadly speaking, yes, that's what happens. However .... the audio and the visual ID's do not HAVE to correlate. Audio performance needs to be fairly 'immediate' , whereas a visual identifier can be slower. Advantage can be taken of this difference to produce visual data that is more 'averaged', to produce more repeatable/consistent/less jumpy information. I've no idea what ML do on their Eqx/Vanquish models, but as an example from First Texas Products: The Teknetics T2 machine used exactly the same processing for audio ID and visual ID. It's design was later developed into the improved 'park-hunting variant', the Fisher F75. This used different processing for the two outputs, and their publicity material drew attention to this improved target ID ability. As a user of the F75, I have seen the odd 'discrepancy' that this produces. We have a lot of coke ( part-burnt coal ) in our UK farmland, and it often reads in the very-low non-ferrous range, but can be in the 'large iron' zone, or up as high as some coins. Sometimes a lump will consistently give 'Iron' audio, but low non-ferrous ID's on the screen.
  3. The 4 inch BH coil is cheap, that's one good thing. It will fit a fair range of machines, including the Fisher F2/F4. These have all the electronics self-contained, so they can easily be refitted onto a custom shaft. I have this coil, and it does seem to pick up electrical interference, though. Maybe the screening/shielding is a bit minimal, being a low-end BH product.
  4. Your 'conductivity table' does have a rather glaring error : you have included ferromagnetic materials among the 'non-ferrous'; namely iron, steel, nickel. These will all read as "Iron" to a detector, as their phase shift will be 'negative' , relative to the non-ferrous scale. Hence why the nickel-plated steel Thai coin reads with a -ve number. The detector sees it as an iron-plated iron item. It's worth accumulating a random selection of foreign coins, for 'scientific testing' purposes. Ask around your friends , see if they will donate / sell you their leftover holiday change for face value. USA money is often used as a reference, that's one coinage worth looking for. For interest, pure nickel is unlikely to be found in the ground, though Canada did make their 5 cent coin from it for many years.
  5. You need to tell us what country you live in, if you're wanting a suggested supplier. The connector is a type known as "M12" , and it's an 8-pin free socket. If eBay is any good in your country, it may be worth looking on there. As an example from a UK industrial supplier, Farnell, there is this 'field-installable' type, with screw-in wire terminals, so no soldering needed: https://uk.farnell.com/te-connectivity/t4110012081-000/sensor-connector-m12-rcpt-8pos/dp/2627715 If you register on Geotech1 forum, there's a thread about the Eqx coil: https://www.geotech1.com/forums/showthread.php?25445-ML-EQUINOX-coil-discussion-thread
  6. A few notes regarding the metal conductivities: The 60% IACS figure for Al is for pure, or near-pure aluminium. Everyday kitchen foil is near-pure, as are the thicker foil types that are used for food containers, pie trays etc. They have the distinguishing characterisitc of being very soft. All aluminium alloys that are created for strength, such as beer/drinks cans, and their ring-pulls/tabs, have noticeably lower conductivity, a typical figure is 37% IACS. Likewise, pure gold is rarely found used in jewellery, it's too soft. Alloying it with copper/silver and sometimes nickel to change the hardness/colour/carat significantly lowers the conductivity. Figures in the 5 - 20% IACS range are typical. For example, 0.900 fine gold, as used in older USA coins, has conductivity of 15% IACS. Cupro-nickel is widely used for coins, and 5% IACS is a typical figure. Your 1986 1 Baht coin will likely read low down, about 10 on the Vanquish ID scale. Here's a decent table of conductivity for many metals/alloys: http://eddy-current.com/conductivity-of-metals-sorted-by-resistivity/ You will soon have plenty more older coins, it's not usually hard to find coins over 100 years old. You have a good machine, it will soon reward you with some great finds. Don't forget to show us, especially the silver ones.
  7. "Is it the strength of the amplitude of the return signal?" Yes, it's based on the change in signal strength as the target is swept over. It's not the total signal strength, as that will obviously include the continuous signal from the ground ( and the continuous coil signal that every coil creates due to imperfect nulling of the wires ). The signal strength varies quite dramatically with the depth of the target. If you're mathematically skilled, a fair practical approximation is that signal strength varies with the inverse 5.5th power of the distance from the coil. This means, for example, that increasing target depth by just 15% (eg. 7" to 8" ) causes the target signal to fall 50%. I assume you're actually referring to the 'on-the-fly' depth gauge than many machines have, the 'Shallow/Medium/Deep' bar-graph? They will just use a simple number comparator system. If signal-strength is more than xx, show the shallow bar, etc. If you were talking about the depth indicator in pinpoint mode, it may be the same system, but extended to 16 levels etc, so a signal that's more than '100' and less than '135' would result in '7' being displayed to indicate 7 inches. Obviously all these scales/bargraphs need some kind of 'calibration standard' target for accuracy ..... and there isn't one. Surprise surprise. It's generally considered that a 'medium-sized' coin is appropriate, something like a USA 5 cent seems a fair example. My Fisher F75 has a surprisingly accurate pinpoint-mode depth gauge. I've investigated its calibration, with coins like US 5c and 1c , and it gives very straight-line graphs for 'indicated' vs 'actual' depth. The F75 does most of its signal processing inside a DSP microcontroller, so can presumably perform quite precise and repeatable assessment of strength. Plus, you would typically move the coil slowly in pinpoint-mode, so it may do more signal averaging, to cut down noise and create a more stable reading.
  8. Correct, the T2 machine does not share coils with the F75/70. That's one of the major differences between those machines - the F75 uses a conventional single-ended transmit coil, making concentric coils practical, which is thought to be a useful option for a 'park detector'. The T2 uses a centre-tapped transmit coil, making concentrics expensive/difficult to produce.
  9. Back on-topic, I see the coil has just two small flat gold-plated pads for the battery charging, like on the previous model. It would be better to have two pads per terminal, to reduce the chance of a poor connection, and to give longer service life, as the plating will wear over time. (this is standard on many switches and relay contacts, where one of the contacts has multiple fingers. As well as making a better connection, it affects issues like arcing and contact-bounce. It's also used on some motor commutator brushes, where bounce inevitable happens, and the inductive nature of a coil-of-wire gaurantees back-EMF voltage spikes.) Alternatively, use larger pads, so the clip-on charging device can use two or more probes per pad.
  10. "I don't know in the UK" The Eqx has proved to be very successful and popular inland, in the UK. The Park1/Field1 modes are pretty decent all-round hunting modes, and Park2/Field2 are effectively 18kHz modes with extra depth due to Multi-freq, so they hit the spot that the XP GMP and Deus on 18kHz do so well, but the Eqx does it better ( especially considering the large coil size ).And the beach guys like it, as it's more ergonomic and lighter than the E-trac/Safari/other BBS they tended to choose, and waterproof too.
  11. It's true that the performance is what matters, and the Deus2 could use innovative tech, but not necessarily deliver gains in 'finding stuff' -- for example clever design may be responsible for the coil having 10 hours run-time, say, whereas if they had used 'regular' designs, the same battery may only have given 4 hours run-time. So the user is seeing a benefit ... but not in finds haul. However your "stability in black sand" criterion is only one way of assessing how good /bad it is. Here in the UK, beach detecting is not the most popular niche, and farmland, ploughed or pasture/grazing , are the preferred locations. Our soil is busy with junk, but isn't actually strongly mineralised, in general. So most of the UK's prospective Deus2 customers are looking for gains that may be delivered by a machine that's nothing special in a 'black sand environment' .
  12. Quote: "Putting an FFT Scope on the detector to count generated waveforms to settle the "number of frequencies" debates is really meaningless and a waste of time, also." I don't agree, I think it's interesting to see what's really being done. For one thing, it dispels all the marketing baloney claims, so people can disregard it. Remember when Minelab added the 4kHz option to the Eqx, and folks were wanting to know if it had been added to the 5/10/15/20 etc mix of the Multi-IQ mode, too? If they were properly informed, they would know there are no 5 or 10 or 15 etc in Multi mode anyway, so expecting 4k to be added would be a bit optimistic/unrealistic. And secondly, a 'scope will show if XP have created something truly different and original, that no other machine has. For example, they may be using 'direct digital synthesis' (DDS), to drive the coil with near-sinusoidal waveforms, so it actually looks like 3 sine waves on the coil, not a mess of square-edged signals. It's just possible they are actually transmitting a single square signal, and doing clever RX signal processing, much like the Tarsacci does. Or... consider those expired Minelab patents for BBS, with sequentially-switched dual frequencies ? There's plenty of scope to do things with that tech. ML only used 3.125kHz and 25kHz for all their FBS/BBS machines. But the 1:8 ratio isn't actually important, and the individual freqs can be tailored to suit the targets you're hunting. So "4k & 32k" for silver coins, "7k & 28k" for general hunting, "15k & 45k" for small target hunting.
  13. It could be fractured wires inside the cable, close to the point where the cable enters the back of the connector. There is often a lot of flexing in that area, close to the strain-relief clamp, and wires will eventually fail.
  14. The 'technical stuff' about frequencies really needs ignoring for now. Only when someone gets an oscilloscope, spectrum analyser etc near one can you really say what may be going on. I'm skeptical about the sheer number of frequencies. My hunch is they may use three at a time, and choose which three depending on the mode selected, so they would use a lower-weighted selection for the 'milled silver coins in parks' mode, a high-weighted blend for 'sensitive' / ancient targets in old European farmland. This is something I'm surprised that Minelab haven't ( yet ) done with the Eqx platform. ( or the FBS/BBS, in fact ). Currently, all the basic modes on the Eqx use 7.8kHz / 18.2kHz / 39kHz, but in principle they could shift them all down, to create, for example 6k / 14k / 30k : same ratios, same maths, just biased towards 'milled silver coin' hunting. So, for this Deus2, the combination of (4 + 28 + something inbetween) may be the high-conductor blend, and ( 7 + 45 + something inbetween) may suit the medium/small target applications. "Pick a frequency, any frequency".
  15. "Shouldn’t target conductivity be included?" I agree, it's a bit vague, especially coming from XP. It's not just 'size' , it's the electrical characteristics that determine whether it's up with the big milled copper/silver coins or down with the thin ladies finger rings. But it seems that manufacturers never speak of the target frequency ( 'corner frequency' / -3dB frequency ) , even though that's exactly what they are measuring on a 'Target ID' scale.
  16. The graphic is showing the 7 frequencies, and their relative strengths for the 4 criteria shown. So you see the highest freq is good at finding the smallest targets, but isn't that clever at discriminating iron.
  17. So, now you've worked out how to open / reassemble the connector, why are you now searching for a new coil?
  18. The connector type number/designation is marked on it, you could probably track down some assembly drawings / exploded-view type of info with some effort. That would give a clue as to what needs doing. Based on what I see, I reckon a three-pronged tool needs to be inserted into the three slots inside the business end of the connector, probably unscrewing a right-handed thread. Eventually it can be pulled forwards, and those slots will just clear the three pins protruding inside the sleeve.
  19. "Why isn't this new model called "Deus Deuce" ?" It doesn't really scan, does it? "Day-uss doose". "Deus+" = "Day-uss plus", scans, but not in XP's native French, "day-uss ploo". Thankfully it wasn't created by software nerds, or they would've called it " Deus++" They could've chosen "Deus FM", = fréquence multiple, but in English that sounds like a radio station. I'm surprised they didn't name it 'Deus Elite' or 'Deus Ultra', they both work in French & English.
  20. I had always wondered if one reason XP were slow to produce a multi-freq machine was the issues with fitting it 'all in the coil' and wirelessly connecting everything. Brute-Forcing square signals onto a search-coil is a big power-consumer, and the subsequent processing of the signal is also a power-user, and would require more physical electronics parts than the regular Deus coils. So then you would need a bigger battery. It all starts looking like the coil would be full of battery/electronics. A wired solution is the sensible option in this case. I'm wondering if this MF Deus runs a wired coil permanently, BUT, it is backwards-compatible with the current line-up of standard Deus wireless coils. It's technically easy, all the micro brains, LCD screen, buttons etc are all going to be there for the MF functions , and the signal-processing for the single-freq Deus is pretty simple compared to what would be required for an MF machine.
  21. The obvious cheap alternative to using the 18 volt '7000' charger is to repurpose a redundant laptop power supply. They ARE regulated, have plenty of current capacity, and you may have one lying unused; they can be obtained free from family/colleagues, cheap from flea markets/car boot sales etc. They are typically 14V to 18V, use the dropper diode circuit to get them down to 12V or so.
  22. Disclaimer: I don't use either of these machines. But I do understand electronics. I think the 18 Volt '7000' charger is capable of charging the '6000' battery, as it has enough current capability, it just puts out too many volts. So if you fitted some dropper electronics to lose 5 or 6 volts, you would have a solution. How are your electrical skillz ? The simplest way is to fit six silicon power diodes in series, these will drop about 0.75 Volts each, hence 5 volts or so in total. It's not really critical, as the nominal '12 Volts' for charging the '6000' battery can be a vehicle battery, which may be 12 V, but could be 13.5V if it's fresh off charge. Suitable diodes would be the 3 amp parts 1N5400/1N5401, which are plenty chunky enough to get rid of the modest heat that will be generated ( it could be 1 Watt each ). A quick look on UK eBay gave these, for example: https://www.ebay.co.uk/itm/261860439805 Mechanically, it would be best if you fix them down, so the wire legs aren't strained. I would homebrew a simple circuit board from plain copper-clad PCB material or VeroBoard / Perfboard. Either have all six in series, or two groups of three, one in the +ve lead, one in the -ve lead. How you arrange the plugs and sockets is where I'm unsure. Do they have commonly available plugs etc? One way is to have a socket that fits onto the '7000' charger output, goes to the diodes, then to the '6000' charging plug. However .... this all works if that 18 Volts is regulated. It may not be so: after all the charging dock accepts a wide range of inputs, so if the 18V varied from 15V to 21 V depending on applied load, everything would be fine for the '7000' charger. But it's not appropriate for my suggested diode solution.
  23. Here's one for you US coin enthusiasts. A New England shilling, found in a random collection, which also includes a Pine Tree shilling and two 'Continental' pewter dollars. A wealthy family from England, whose ancestors had business with the US in the early colonial days, "discovered" the coin among a random collection of US / British / Spanish coinage assembled by the family in years past: https://www.bbc.co.uk/news/uk-england-tyne-58982457 Some history of the NE coinage: https://coins.nd.edu/ColCoin/ColCoinIntros/NECoinage.intro.html
  24. Silver and gold coins from the 1700's / 1800's , so they illustrate it with a banner photo of some Roman gold coins from 1400 years before the ship sank.... An interesting read, regardless.
  25. That ear wear shown by 'againstmywill' is exactly the wear I was describing in my post on another 'broken ear' thread: People really should check their ears regularly for this, and take precautionary measures, such as using the shims I described ( cheap ), or possibly replacement of the rubber washers with new ones ( more expensive )
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