PimentoUK

ED is in the U.K, he probably didn't put the Lesche on his shortlist because of the cost, though there's also the issue of warranty etc, always troublesome when things get international. By 'unavailable' I meant there are no major dealers selling them, you would have to purchase direct from the US. So there's high postage charges, international payment fees ( eg. PayPal ). Then you may get lucky and it goes through customs easily because it's low value and small. But if it does get the official treatment, add 9% import duties, then 20% V.A.T on top of that. It could easily top 60 GB Pounds ( 75 US dollars). Whereas the UK made Evolution products would be about 30 Pounds, Garrett's Edge is 37 Pounds. digging tools And because no-one uses the Lesche here, we don't really have good data on how strong, reliable, hard-wearing, ergonomic etc it is compared to other offerings. It's clearly an effective tool, as many of the other diggers seem to mimic its design, including the 'Raven' ones listed on the metaldetectingauction link.

Steve: Lesche's are unobtainable here in the U.K, it would cost a ludicrous amount to import one. Evolution products seem well liked by folks on UK forums, the only thing that will wear out is the rubber handgrip.

It's good to see you're doing well over here, some rain arrived just in time to soften the summer concrete for you. A Bronze Age tool is on my wish-list, I've found fragments, casting scrap, but not the full item yet. For everyone, here's a summary of British coins, with some photos of very choice examples: Tony Clayton Site .. the bronze Victoria penny: bronze penny

I stumbled across a few UK magazine issues, Searcher and Treasure Hunting, on the Archive site: magazines

As a Geotech1 regular, we've discussed this complicated issue. The depth that eddy currents penetrate depends significantly on the frequency you're applying, so higher freqs do indeed 'see the skin', and lower freqs penetrate much deeper. But the other relevant variable is the target metal: specifically the electrical resistivity ( or conductivity ). Good conductors, like copper, silver, don't support much skin penetration. And lousy conductors, like most cupro-nickel alloys have much deeper skin depths. For the mathematically inclined: The skin depth varies with the square-root of the resistivity. So for example a metal that has resistivity 4 times greater than pure copper will have a skin depth 2 times greater than copper. To use real data, coin cupro-nickel has a resistivity about 20 times that of copper, so skin depth is about 4.5 times greater ( square root of 20 ). Currents flow 4.5 times deeper into the metal. So your typical machine will see 'all' of a 5 cent cupro-nickel coin. But probably only the outer 0.5mm skin of a silver Morgan Dollar, for example. And the cladding on a clad 25c coin contributes little to the overall response. And, yes, magnetic characteristics are important, too. Iron/steel/pure nickel are ferromagnetic, and really don't support deep currents at all, and it gets worse as test frequency increases. This is why high freq machines like the 100 kHz Compass models ( Yukon, 66 ? ) can 'see through' small iron. At 100k, they only see the tiniest skin of a nail, which makes the nail very 'small'. - meaning the nail doesn't give much signal itself, plus it doesn't distort the magnetic field much, so there's less masking, and other targets become visible.

The earlier Rutus model, the 'Jupiter' , also had mixed-mode audio.

JackP, you're misunderstanding the purpose of the S-rod. When you're swinging the Eqx on the stock straight shaft, at the end of each swing, when you change direction, the bottom-heavy coil/shaft wants to twist in your hand. The solution to this is to move the coil, or the coil and rod forwards. There should be some 'sweet-spot' where there is minimal twist during coil direction-change. Too far forwards ( more than 6 inches?) and it would twist the other way. Ways to achieve this would include: 1 ] An offset coil ear device, so the lower rod joins the coil towards its rear ( like the Teknetics 11"x7" bi-axial etc etc ) 2 ] An S-bend middle rod, like Lisa's example, above. 3 ] A single 'forward' bend rod, just below the handgrip (either on the upper rod or the top end of the middle rod) This issue has been discussed before, on here, and on other forums, like Tom Dankowski's. I am currently in the planning process of my own 'single-bend' shaft, as I don't care for the stock one's behaviour. My plans will also address the poor breakdown size, too. It's a winter project ...

I would like to enter this draw, please. I feel I have the skills to fix it, too ... I just don't have any yellow metal to warrant warming it up, so bronze casting is its likely use. Thank You.

Assuming you're referring to VLF machines: The power consumed by a coil does not vary at all with size. If the designers have done their job correctly, the electrical resistance should be the same, and in operation, the voltage applied to the coil should remain constant, too. "Ohms Law" fills in the missing info - the current must be unchanged, too. Hence power is unchanged. Even if there was, say a 10% variation with a particular coil, you would be hard pressed to observe it's effect on the total detector power draw. Take the frugal Teknetics T2: approximate power put into the coil is 20 milliwatts. Total power draw of the whole machine is about 300 milliwatts.

You forgot Pinpoint Mode. Pretty tricky to use for actual hunting, unfortunately. And as for it's effects on your numbers, that's a tough one to judge. If you're running at 5kHz, for example, does the pinpoint work at 5kHz, or Multi-freq? It's something I had pondered not long after I got my Equinox, and I think an oscilloscope would easily answer the question ... a rainy day experiment, I think. You're also keen to 'write off' the lowest sensitivity settings, but I was quite pleased to see that the machine could be turned right down. This is good for shallow-target hunting in parks, where you only want the easiest to recover targets, to minimise grass damage. An annoying feature of 'another machine' I own is that even on the lowest sensitivity, it's too 'hot' for this, and you have to rely on your pinpoint probe to judge if it's truly shallow.

There is a German ( Austrian? ) depth test out there on the web, that does a pretty similar thing. I can't recall if they 'drilled' the hole for the pipe to go in, so as not to disturb the earth. I'll see if I can find it, there may be some tips to pick up from it.

I see you're interested in saving bandwidth. I'm no web expert, but did help Wally find a few issues with Tom D's forum. So a few little things I noticed on your site: On the right side of most pages, there's the 'recent classified', and 'other forum posts' section, all of which have users avatar in miniature. These are actually downloaded as the full-size avatar images, so they total up to a few 100k filesize. Could the avatar simply be replaced by a big black dot, as it is on the left side listing? Related to this, when viewing the Classified page, all the 'recent classified' ads are duplicated on the right, needlessly. And your 'smileys' are massive, 120 pixels wide, some of them, with corresponding filesizes of 15k + . Example the 'oh my' one: The 'like' thumbs-up is 7K: These could all be resized to more appropriate dimensions and hopefully smaller file sizes.

In which case, please ignore all my advice. Those primary Lithium cells put out around 1.8 Volts when fresh, that's where they differ from regular alkaline cells ( and NiMH / NiCad ). It's likely that Fisher didn't design the pointer with those cells in mind, hence the circuit not behaving. As far as Why?, it's hard to tell, no-one has reverse-engineered one. I've heard of a similar issue with the Tek T2 / F75 when run on these cells. The total voltage is over 7 V, ( four AA's ) and the 6 Volt regulator circuit doesn't function, and the resulting supply is unregulated and noisy.

Please be more specific: " Lithium AA " Do you mean those curious KentLi cells, that are 1.5V when discharged, but need a special charger? They are actually a 14500 ( AA ) size lithium cell, with a switched-mode voltage regulator electronic circuit squeezed onto a small circuit-board at the end, which reduces the typical Li cells 3.6-4.2V volts to 1.5V. And can potentially create an amount of electrical interference in the process. Or have you actually used a 3.6V Li cell in place of regular alkaline etc cell ? In which case, good luck, hope you haven't permanently damaged anything with the major over-voltage.

On the 10" GB2 coil, you can also see a small axial-leaded component near to the 'heel' of the inner RX coil. This is most likely a resistor, and it's joined to the single wire loop that runs on it's own between the two main coils. This makes a simple R-L (resistor-inductor ) network, which looks like a target to the coil, likely a very small low-conductivity one. This is there to help get the coil null more precise, there's only so much you can do with moving wires around. Similar effects can be had using small bits of metal, like sheet lead, placed in 'the correct position'.

I've fixed the links in my post, which was hard work. I'm going to have to practice if I'm going to post any more links in the future. The GoldBug2 has a few recognisable features: The fans of 6 or 7 wires are where connection is made to the graphite paint finish on the shell inner surface - one for the top, one for the bottom, I assume. The wires are bare tinned copper, possibly melted into the plastic, possibly taped down. Then the graphite is painted over the top of everything. There's a capacitor in there, the rectangular thing on two wires, typically a wound polypropylene type, in a little plastic box. This will tune the transmit coil. The excess of spare wire is what would be used to get the correct null, where there's very little output from the coil when nothing metallic is nearby. This could be moved around, formed into small loops, etc, in addition to moving the location of the central ( RX and bucking ) coil assembly about a bit.

Quote:"Looks like a ferrite choke inside the GPZ 14" stock coil too but the wires go into it tightly bunched and come out loose. Somethings going on in there" Yes indeed. The TX coil is would from multi-stranded Litz wire, appearing 'fatter' on the images. It's then soldered to short lengths of 'regular' wire ( I don't know what, probably just PVC-insulated equipment wire ) , which are then soldered to the PCB ... or maybe it's the coil cable inner directly soldered to the Litz. The ferret .... well somewhere in ML's patents is the answer. I recall that big blob solder joints were detectable to PI's in some less-than-ideal way. And the ferret 'hides' the joints, somehow. I'll have to trawl Geotech1 to find the details. [ferret's may be known as polecats in your country ] Update: Here ya go ( after 10+ edits, I'm still struggling to get the links to work ... Iwish there was a 'post preview' option ) Patent US20130057286 https://www.geotech1.com/forums Also: MD-Hunter's blog has X-rays of the Nox coil, and a few other types.

That old Whites was picked up for 10 Pounds ( about 13 US Dollars ) at a car boot sale ( like a flea market/garage sale event ). It took a while to work out what was up with it. Several things it turned out, but in the course of refurbishment, I've made it better that new, the residual background hiss is much reduced. This may make it more sensitive, or just nicer to use, I don't know yet. I had some ideas related to tinkering with the audio, which is pretty simple and hence easily changed. And there's lots of space inside that big box for add-on kludges. A curious machine, with the ability to do reverse discrimination, which I understand is for location of black sand areas. Not likely to be much use to me, though.

Hmmm ... shoulda kept quiet about that. It's a short-ish list of what's been done, and a long list of potential projects, none of which I have any time for, currently. It's on a custom shaft. It was originally simply a project because I wanted to do it. So I did the groundwork research, planning, obtained some suitable metalwork, then it all went quiet. Until my original shaft snapped in half, unimpressed by FT's engineering, I have to say. Then it became a more urgent project, which I'm now finally finishing off. There's a self-built cordless headphone link built into it. Though it works OK, I'm not convinced it's perfect ... as a fall-back I have a couple of sets of TurtleBeach cordless gaming 'phones I could hack. The RX gain has been increased, originally to bring the 5" coil alive, though it also benefits non-motion hunting, like hoard-hunting and detecting overgrown wild areas. It has no readily observable effect using the stock coil, except perhaps on dry sand or a freshwater beach?. I was intending to make it switchable stock / hi-gain .... some time. Backlight on/off control is a half-done project. I rarely use/need it, so I permanently disconnected it. But on occasions I wished I could turn it on, so came up with a design, but never finished it. Among the 'projects' are some coil builds. A very large ( approx 18" x 12" bi-axial ) and a two-box conversion. Both really for large-target/hoard-hunting, though the 18x12 would still get coin-sized stuff. I worked out a plan for an all-metal/disc-mode toggle circuit, but that one will probably not happen. With almost no changes, it's possible to run the machine on a single AA Li cell, I was going to do some experiments into the viability of this. It's also been fiddled with for scientific measurement purposes. Raw target and ground signals can be measured internally. A DVM will give useful data, but a data-logger would be better. My first attempts involved a laptop PC sound-card. Fitted with an external chopper circuit, using SpecOszi logger software, and a QuickBasic program to process the data. It wasn't that good, the next attempt will use a recently-purchased external USB sound-card suitably modified, and Audacity software to do the data capture. And I haven't mentioned all the pinpointers and their mods.HeHe.

Thanks for the welcome, guys. I should've mentioned I use a Fisher F75 as my main machine, an F2 as a backup, and as a fun project, a vintage White 2/D hip-mount in need of some love. All my kit is tinkered with, needless to say.

Hi to you all. I'm from the south of England, I mainly detect farmland, woodland, and a bit of park hunting for something different. No prospecting, and I've yet to beach hunt, but one day I must try.... I mainly post on a UK Forum, but sometimes contribute to Dankowski's Forum, as user Pimento. I'm an engineer, who likes the technical aspects of the hobby, so that's where my contributions are likely to be. But it's always good to read what others in the hobby get up to, and Steve seems to have created a nice Forum here. So I'll be checking in regularly, even if my posting is infrequent. Thanks for reading.