UKD2User

Have you decided against the D2 ? The Manti seems to be least obviously ahead of the D2 when it comes to busy European soils.

It's probably not appropriate to try and identify the transmit and receive sides in this photo!! 😇😁

I think that the laws of physics tend towards the conclusion that: 1. Depth and/or ferrous mineralisation, or adjacent ferrous masking all tend to make things sound/look worse than they should; and, 2. Size and shape (holes or points concentrating electromagnetic flux) tend to make things sound/look better than they should. All the clever tricks in software/settings cannot stop these effects, just minimise them in certain situations.

I don't know about the fe/co 'horseshoe' because I don't use it, but certainly on a big, rusty, odd-shaped piece of iron the xy can be as misleading as the tones - only the size of the target gives a hint that it might be big iron.

I watched the video when it came out and again just now. I don't think what he said is at odds with anything I wrote above, except that he mentioned the "halo effect caused by damp ground" - I think this is just his way of describing a general background mineralisation caused by metallic salts dissolving in groundwater making a conductive 'ionic soup'. Google tends to support my definition of 'halo effect' (which is similar to but different from the way he used it) e.g. this example chosen fairly randomly: https://www.metaldetectingworld.com/halo_effect.shtml I don't know Gary personally, although I know the area where he filmed that video - it's a few miles from my home. His videos are great but his choice of words is not always precise!

I prefer to use the XY screen, as it gives more info. I also use my ears and sweeping over a signal at 90 degrees to help make the dig/no-dig decision. I only very occasionally get fooled by big lumps of rusty iron with holes and/or sharp corners. PS I don't feel bad about digging the occasional bit of iron, because I know that it means I am less likely to be missing good targets masked by iron.

I've always thought of the effect of conductive/salty soil as being different from the halo effect. I think that conductive/salt subtraction aims to neutralise the effect of a pretty much uniform distribution of conductive mineral salts dissolved in water (mainly sodium chloride solution) evenly spread out in a layer of wet ground and/or water. I imagine that the return signal from this salty stuff is fairly uniform and is at a predictable frequency/phase-shift - so is easy enough to 'remove' using an algorithm similar to the ones which eliminate the general effect of the ground (as long as the set of frequencies transmitted and analysed in that particular operating program/mode cover the salt response region). The halo effect, as I understand it, is about corrosion products forming a kind of graduated 'shell' around a metal item - a 'shroud' of rust, or a 'coinball' stuck together by copper/silver/nickel salts leaching into the soil around the coin. I think that this kind of thing happens to a greater or lesser extent in all soils, and it's obviously not a uniformly distributed thing.

I think that all machines probably do it to some extent - perhaps not so noticeably. My Nox 800 definitely does it. I think that the basic laws of physics make it inevitable.

Whoever makes a machine that can reliably discriminate alumin(i)um will make a lot of money! I believe that aluminum is paramagnetic, although this is a very weak effect I think, which may form part of a technical solution. With my D2 on the beach I once found an old-style beaver tail ringpull (sans tail) in the same hole as a 925 silver ring. I could tell there were two separate targets there and they sounded different - even though of very similar size, shape and conductivity. I find that the audio filter setting (Manticore has similar advanced audio filtering features to the D2) can help to make many pieces of aluminum trash sound trashier than most treasure, but you've really still got to dig the stuff.

Fascinating. Interesting to see which side is the 'transmit' side!

The dropdown is visible within the web-browser-based update program.

Looks like you need to make sure the phones and the remote are both running the same firmware version.

When you run the web-based updater you can select which version you want to use. Make sure you have already created a user account on the website.

Lucky you! 😀 Cold and rainy in the 40's here.

Was cold weather a factor, I wonder? All Lithium cells work much less effectively at low ambient temperature.

You're right about the Nox I'd forgotten about the WM08 'protocol' and of course they were ML80's If I'm right about the Achilles' heel of the WM08 being its poor antenna arrangement, I hope they fixed that on the 09...

My problem with the WM08 was with other people's phones (especially at the beach). The ML85's were always more resilient than the WM08 even though they used ostensibly the same protocols. I wonder if the WM08 antenna was a poor design/location.

I found that the WM08 unit was quite susceptible to EMI - especially from nearby cellphones. Is the WM09 the same/better ?

Don't forget that the 40kHz transmitted signal will have a reasonably strong 3rd harmonic component at 120kHz - so the Nox is actually transmitting signals at 40kHz and 120kHz (plus a little at the fifth harmonic of 200kHz!). I strongly suspect that the Nox only analyzes the return signal up to about 40kHz though, but only MineLab know for sure!

Yup. Just like using the original Nox 6/800 with horseshoe mode on. I agree.

Lowering Disc on the D2 does not change the TID of a given target - it just makes it sound like a non-ferrous target (if the 'drug' TID is above the Disc value) or ferrous (if the 'drug' TID is below the Disc value). As a separate but related idea, what TnSharpShooter seems to have discovered - when looking at his 'BirdDog' settings - is that Notch (as opposed to Disc) does seem to alter the displayed (and heard) TID value - which is kind of weird, but useful in identifying otherwise 'drug'/masked non-ferrous. So - as I suggested previously - the advantage you get from lowering Disc is in hearing more targets (some of which will have been 'drug' down) as non-ferrous than you otherwise would. You therefore miss fewer good targets, but probably hear/dig more junk too.

And I've given my explanation of the effect he describes.

I think that it's sort of the other way around: The high mineralization means the only way to 'unmask' a non-ferrous target is to reduce the 'swept volume' of soil being analyzed under the coil at a given moment (by using higher reactivity and/or by using a smaller coil and/or - to a much lesser extent with modern machines - slowing your swing). By reducing the 'swept volume' by whatever means, you are increasing your chances of 'seeing' the non-ferrous in amongst all the other stuff. What I'm saying is that 'masking' can be due to ferromagnetic dust evenly dispersed through the soil (what we call mineralization) and/or by bigger lumps/particles of ferromagnetic junk (the stuff we tend to think of when talking about 'masking'). Based on the above, given that unwanted ferrous stuff (of whatever particle size) under the coil in the 'swept volume' always tries to overwhelm the non-ferrous signal from the same volume - dragging it down towards ferrous - lowering Disc will help you to find good targets that are having their TID being 'drug down' (as some US Utubers say!) by this effect and would otherwise be ignored. The downside is that your ears and brain potentially get overwhelmed by sound 'information'!

Newsflash - every post on the internet = opinion 😉😁 To be fair to me (whoever I am!) I have some supporting logic/evidence for my 'opinion': 1) Paystreak's video below (in what I think is quite strongly mineralized ground). 2) From first principles - a) If you keep swing speed (and all other things) the same, a higher recovery speed means that the machine is analysing a smaller volume of ground - to come up with a determination - than it is at a lower recovery speed. This stands to reason (!) and is consistent with the diagrams/descriptions in XP (and Minelab, and no doubt others) manuals - although these show a discrete (e.g. nail), rather than diffuse (e.g. black sand) iron 'masker'. b) All detectors have to work very hard to see a non-ferrous 'needle' in a ground 'haystack'. The return from even benign, un-polluted, soil is very large compared to the return from a deep and/or masked non-ferrous target. Searching a smaller volume of soil (using a smaller coil, for example, or as in this case, using a higher reactivity) improves the chances of finding a non-ferrous target in that 'swept volume'.

Completely agree. What is less obvious is that lower recovery speeds can tend to make a good target sound more like iron than higher recovery speeds - all other things being equal - especially in mineralized ground. Of course, the trade-off with a higher recovery speed is a loss of depth (which is less marked in mineralized ground than in clean ground). Based on the above, you may benefit from a lower disc setting if using a lower reactivity in the hope of more depth.