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Everything posted by PimentoUK

  1. Here's where I drew my info from. The English translation of the MD-Arena website page. Down towards the end of the readers comments [ie. angry Russians arguing ] are a scope screengrab, and some spectrum analysis. MD-Arena page I've attached the 'scope screen photo here, and also an Equinox Beach Mode waveform that Chiv posted on Geotech1. They match ( to my engineers eyes ) , what wasn't detailed was what mode the Vanquish was in at the time. It just may be different in some or other mode. So a little prudence is called for.
  2. This extremely thick grease is sometimes branded as 'Kilopoise' grease ( from the unit of viscosity ), one possible place to look is HiFi specialists, as it's used to damp down tone-arms on high-end turntables. Another possible source I have heard of is for radio-control vehicles. They use heavy grease in limited-slip differentials, one brand is Traxxas: traxxas grease These are just suggestions, I've never used any of these products on detector controls.
  3. After making some errors yesterday about what I believed were the Vanquish operating freqs, I have some proper facts today: Those Russians over on the MD-Arena website have been poking about on a Vanquish, and have posted a frequency spectrum of it's output, and a 'scope image of its waveform. And the surprise result is .... it's running like the Equinox Beach mode. The waveform is an exact match for the Beach mode scope capture's that Chiv made on Geotech1, and the frequency spectrum matches, too. So that is 7.8 kHz / 13 kHz / 18.2 kHz / 39 kHz Ratios are 3 : 5 : 7 : 15 How it then goes on to process these four is of course unknown .... it could be a straight 'copy' of the Eqx beach mode code, that would be the quickest simplest way of doing it - make use of the R&D that's already been carried out. If they only need to process two freqs for a given mode, they can, no need to change the transmitted output. I suppose this opens up the possibility of hacking Vanquish coils onto the Eqx ... though don't hold yer breath. I'll try and add some pics and further info later.
  4. "Here you go Pimento" Got to say, I've recently obtained a Deteknix P.I pinpointer in need of some minor repair. It's now working fine ... and my thoughts are turning to hacking it with a 4 inch coil, much like those scuba detectors. It can wait .. too many other daft projects: [ discriminating pinpointer with wireless headphone link ? ] [ two-box conversion for my F75 ? ] + more....
  5. 'Best coil size' depends on the type of machine: PI; single-freq VLF; multi-freq VLF. PI is easiest, a round mono coil can be mathematically analysed, and you can ( within limits ) assume it doesn't pick up much ground signal, to complicate matters. But anything with a complicated coil, like a DD ( or even an OO ) is beyond maths, and probably needs computer modelling ( like finite element analysis ) Then VLF's pick up ground signal, so plucking the small target signal out of the large ground signal becomes your next hurdle. Different coil sizes pick up different levels of ground signal . Multi-freq VLF's minimise ground signal effects, which ought to make things a bit easier. But probably not in practice....
  6. That's where there's a need for more Eqx coils. For specks like that, optimal coil size is probably 2 or 3 inches. ( I can't back that up, even a big discussion on Geotech1 didn't resolve 'best coil size' ) I want to make a 5 incher, pretty much like a First Texas one, and it's got to be easier than my number two project, an 18 incher ... but I don't know how you'd make a 2-3 inch one. Probably make it like a fat SunRay probe ? Plenty of space then for the electronics board. PVC water drainpipes come in tubes that could be suitable....
  7. For those of you pondering Nino's oscilloscope screengrabs: The lower display shows a spectrum analysis of the waveform transmitted. Horizontally, it's 10 kHz per division, and 20 kHz is dead centre. So the three peaks are in the 7-8 kHz area, the 18/19 kHz area, and 39kHz or so. When analysed more precisely, these are the 7.8 kHz, 18.2 kHz and 39 kHz frequencies. The ratios 3 : 7 : 15 mean that: (3 cycles of 7.8kHz) plus (7 cycles of 18.2 kHz) plus (15 cycles of 39 kHz) all add together simultaneously, to make one complex waveform that takes about 385 microsecs to repeat ( 2600 times per second ). The differences between the gold modes will be in the way these three freqs responses are interpreted. Eg. heavily biased to 39 kHz; a bit of 39k and a bit of 18.2k ? No-one knows.....
  8. EDIT: please ignore most of this "Vanquish Tech data" stuff ... turns out I've been misled by unverified sources ---------------- What the Vanquish spec says is : “VFLEX-IQ” with the choice of 7kHz or 18.75kHz single freq operation. Now 7k and 18.75k are pretty decent choices for single-freq operation, the 7k for milled coin hunting and general 'larger targets' , the 18.75k better for those 'nickel' targets, like gold finger rings, ancient European coins. But .... they are actually in a ratio of 3 : 8 , which is an easy to generate multi-freq waveform. Every 3 cycles of 7k, there are 8 cycles of 18.75k, so the whole waveform repeats every 437 microsecs ( ie. at 2344 times per second ). My guess is that these two freqs could be the only ones. It's running at 7k with the 18.75k for ground compensation, and at 18.75k with the 7k for compensation, and it's doing a 'best of' decision when interpreting these two 'readings' . And by not having any 39k / 40k operation, it puts much less constraints on the technicals of the product. Amplifiers need less bandwidth. Analogue-to-digital converters need only be half as fast. The DSP microprocessor only needs to do maths at half the rate. The coil needs less precise nulling. All these things make for a cheaper product. No doubt someone will stick a scope on one some time, then we'll find out. ------------------------- Update: "This was his response refuting another poster" ...yes, I am that 'other poster', so it does "look familiar". And that's where the difference of opinion about Gold mode originates. Chiv, and two others, see Gold mode as 7.8/18.2/39 , exactly as per Park/Field, but we would assume putting more emphasis on the 18.2k and 39k to favour the small nuggets. Carl is the only one to state the two freqs in his quoted post.
  9. "Equinox likely uses a combination of only two transmit signal frequencies to generate its multifrequency spectrum based on user measurements using spectrum analyzers documented in multiple posts on this site. The different mode spectrums for Park, Field, Beach, etc weighted towards high and low frequency spectra for Equinox are likely generated using different pairs of frequencies. If you read those threads, and the ones on Geotech1, you'll see the Eqx uses 3 freqs in most modes, and 4 in Beach Mode: 7.8kHz / (+Beach 13 kHz) / 18.2 kHz / 39kHz. Ratios are 3:(5):7:15. The weighting does vary. Park1/Field1 seem to be favouring the 7.8 kHz, Park2/Field2 favour the 18.2kHz. I'm not so sure about Gold modes ...opinions differ, and I personally have a 600 model, so it's not something I can check myself. Back to these aftermarket coils: There are technical merits to putting the pre-amp inside the coil. By relocating the ML pre-amp into a seperate box near the control-box, they are potentially losing some of those benefits. It's a simple solution, that works, but it's not ideal.
  10. "the fact of the matter is that they are both supporting Multi-IQ" Multi-IQ has no definition. They could make the Vanquish have completely different frequencies, and a different number of them, eg. just two, for example. They could issue a software update for the Equinox that gave it totally different frequencies, too. X-rays of the Vanquish here: forum thread And they are also on the MD-Arena website
  11. "The Equinox coils have an 8 pin connector. The Vanquish coils have a 7 pin connector, so...............I wonder what that 8th wire does???? " Guys .... you're making so many assumptions about the similarity between the Eqx and the Vanquish, and their respective coils. They may be so incompatible it's not even slightly viable to 'hack' one onto another. And the answer to your question: - the Eqx uses 7 of the 8 pins in its coil connectors. And from what I've seen, the pre-amp inside the Vanquish coil is simpler, a single-chip circuit (like an XTerra), compared to the Eqx which has a hybrid transistor/opamp configuration. This makes the Eqx lower noise and faster. As we don't know what freqs the Vanquish operates at (yet) there could be many technical differences, but lowering cost will obviously be the driving force.
  12. "Not so essential" was meant to infer that the majority of potential customers wouldn't be wanting it to operate completely submerged. I am unsure what the 'Terra' is supposed to be, I'm wary of making assumptions as to what niches it's targeting. I would suggest 'bad dirt' would be a PI strong point, so the lucrative nugget-hunting market would be an obvious direction to develop the AQ.
  13. My thoughts: As it's well known that wireless systems work poorly through water, particularly those at 2.4 GHz , the 'water absorption' frequency, it's perhaps no surprise the AQ is corded 'phone only. However it is more viable on a land-based machine, where having a waterproof machine is a good thing, but a submersible one is not so essential.
  14. I guess this machine will be bought by serious hunters, and such folks would want to charge two packs simultaneously, or failing that, be able to do a 2 or 3 hour charge on one, then do the other.
  15. I don't know if FT are getting feedback from this thread, but ... a question was asked on a UK forum about charging both battery packs simultaneously. Based on the above photo, it seems that one at a time is all that's possible , with the charger supplied. Do you, Rick, have any indication of charge time, eg. 5 hours; 16 hours ? The charger's label indicates 400 mA max current output, and it seems likely the pack contains 8 or 10 x AA cells, which would suggest 5 hours is the minimum charge time ( if 2000 mAh capacity cells ).
  16. I guess your illness means you weren't able to make a " Reboxing Video" ??? Hehe. Get well soon, Sir.
  17. The switches are small, cheap, fairly fragile things, it's almost inevitable that they will fail at some point. You can see them on this internal photo: eqx_PCB The sealed case means no access for repair. And removing/inserting the battery isn't exactly simple, so no get-around there. And I very much doubt that it's possible to do any clever software 'work-arounds', either, like swapping the on/off and the backlight button functions.
  18. Ring-shaped objects give a stronger signal than solid discs, and read 'higher up' the discrimination scale that most detectors have. And aluminium is a good electrical conductor. So I think it's worth experimenting with large aluminium washers, example 1" / 26mm size. A UK supplier for illustrative purposes: https://www.gwr-fasteners.co.uk/aluminium-washers-244-c.asp These should be quite distinctive and easily found with a detector, and they're reasonably cheap if you're going to be using lots of them.
  19. A simple thing worth trying is to perform a Factory Reset on the machine, then re-set your discrim etc. You may have some inadvertent notching set up, and it's simplest to reset, rather than figure out how to untangle the notch.
  20. That map of Europe looks a bit 'distorted' to me. I'm sure the UK isn't that big. Not to mention all of Scandinavia and the Baltic States are missing - Norway, Sweden, Finland, Latvia, Lithuania to name a few.
  21. A process known as Bioturbation is a very significant factor in coin sink. Essentially, earthworms disturb the soil around the item, until one dry/wet/cold/whatever day, the conditions allow it to drop 2 or 3 mm. Repeat this for 100 years and your target is 20cm ( 8 inches) down. If the ground is inhospitable to worms, the sink is much slower. Unfortunately for us, earthworms tend to live in the top 30cm ( 12" ) of soil, because that's where the plant matter they eat is located.
  22. If it's laying on the surface, or nearly, then the obvious thing to try is lowering the sensitivity right down, to 5 perhaps, then you'll only get signals from shallower stuff [ or big stuff deep ]. Try a few experiments with a 'similar' mans ring.
  23. Sounds terribly over-complicated to me, surely a couple of bent coat-hangers, maybe with a pocket calculator hot-melt glued on top, would find all these targets?
  24. Sorry to hear about the accident, it sounds serious , was fire involved? How damaged is the search-coil for the Equinox ? I would actually be interested in obtaining it if it was not destroyed, I'm wanting the electronics board out of it for a tinkering project. Thanks.
  25. My guess is it's made of 9ct gold ( or some similar low-ct like 10 or 14) , so you need to get it tested, under XRF. It may still be worth 40% of a genuine one. You can also perform a density test on it, which will give a pretty good guide to ct value. I've copied this post of mine from a Geotech1 thread: Here's how to measure the volume, and also the density, of un-hallmarked jewellery etc. See the attached photo: A ) Place a small container of water ( 20 - 50 cm3 ) on your scales, and 'Tare' the readout to zero. B ) If you're wanting the weight of the item, place it alongside the water container, and take the reading as indicated. C ) Using monofilament fishing line / polyester sewing thread / very fine wire, lower the item into the water, so that it is just submerged, and not touching the bottom or sides of the container. Make sure there's no air bubbles attached. Take the indicated weight reading. Reading C is the weight of the displaced water, which, because water has a density of 1.00 g/cm3 , it's also the volume of the water in cm3 . To calculate the density, divide the weight in reading B, by the weight in reading C. So in the example, the finger ring weight = 9.50 grams. The volume = 0.92 cm3. The density calculated as 9.50 / 0.92 = 10.33 g / cm3 which is typical for Sterling Silver ( tech data usually gives a figure of 10.36 ) As a guide to what density some precious metals are, some figures are: Metal Density --------------------- 9ct gold 10.9 to 12.7 14ct gold 12.9 to 14.6 18ct Yellow gold 15.2 to 15.9 18ct White gold 14.7 to 16.9 22ct gold 17.7 to 17.8 Pure 999/24ct gold 19.3 Sterling Silver 10.2 to 10.3 Pure silver 10.5 950 Platinum 20.1
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