Jump to content
Steve Herschbach

Metal Detectors With Reliable Target ID Numbers

Recommended Posts

is gain equal to sensitivity? in other words, should I lower my gain if the machine is noisy or falsing when gold detecting? 

Share this post


Link to post
Share on other sites

12 hours ago, gambler said:

is gain equal to sensitivity? in other words, should I lower my gain if the machine is noisy or falsing when gold detecting? 

Gain and sensitivity normally are the same control. Reducing sensitivity always increases stability but obviously it is a trade off. You have to find the best balance between raw power and stability - useable power. The old rule of thumb is increase gain/sensitivity until the machine becomes to unstable/noisy, then back off a hair.

  • Like 3

Share this post


Link to post
Share on other sites

thank you steve

Share this post


Link to post
Share on other sites

Excellent read Steve

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By rockhound
      Found some clubmates discussing who (and when) invented the first pinpointer. Google just found some hints. Feel free to discuss...
       
    • By palzynski
      As I like the Vanquish serie ( I already have a 540 ) 🙂, I decided to buy a 340. Over here the 340 price is 240e , 
      so quite cheap ,almost the price of a coil ... My plan was to do some tests with the 340 and resell it later ..
      A few days ago I did my usual static depth tests. See pics below. I could see that the 340 had the same depth 
      than the 540 V10 , either on a big coin at 11inches or a small coin at 6inches, so very good news for the 340. 
      I could also check that the 340 is as sensible as the 540 V10  on tiny targets lying on the surface like small
      hammered coins , good news again ..
      So today I went to an open field cultivated with wheat. Sandy low mineralized soil. Low to medium iron trash.
      Actually the conditions were not ideal because the field has not yet been ploughed and I had to sweep the coil 
      3 or 4 inches above the ground because of the cut wheat. I found many targets , mainly 1st WW rubbish... 
      Among that stuff I could find 2 coins , a 16th century copper coin and a tiny roman bronze coin .. 
      Very happy with these 2 coins 🙂, the copper coin displayed 15 id and the roman coin 11 id . 
      The 340 is very accurate and deep, the same as the 540 V10 actually , I did not see any difference in the field, 
      the only thing there are only 3 tones for the 340 instead of 5 for the 540. Iron separation is the same between the 340
      and the 540. The V10 coil is excellent for coin shooting , and very light .. 
      The only limitation I see for the 340 , the same as the 540 and other multifreqs MLs , are high iron trash areas , 
      so the 340 is a little too chatty and slow on these areas . And unfortunately there is no dedicated "FA" ( fast ) mode 
      like on the Teknetics T2 ... On such iron trashed areas I prefer to use my Deus .
      So if you dont need wireless and backlight and you detect on low/medium iron trashed areas , 
      the Vanquisg 340 offers a great performance for a very limited budget. Even experienced users will be happy with it ...
      I was thinking of reselling it but eventually I will keep my 340 for the moment .. 🙂 


    • By goldenoldie
      Those impressive video results of the Fisher Impulse AQ with its 12.5” mono coil  on the 10K Gold ring at 17”-18” and 14K Gold ring at 19”-20” as did a 22K Gold ring drove my curiousity to air test two Gold rings using a QED in its Beach Mode-11 operating at its pulse delay of 7.5uS with a NF 12” Advantage mono coil.
      For my test, the QED’s settings were Threshold-B at 5 below Null and Factory Default for Threshold-A at 30 and Gain at 1.
      (Threshold-A settings range from a 1 up to 90 and the Gain settings range from 1 up to 10}
      The results for a clear response on a 3.04-gram 9K 21mm diameter Gold ring was 17” and on a 2.05-gram 18K 19mm diameter Gold ring was 16”.
      I have no idea how a QED using its Beach Mode would operate within a Beach environment and my intention is not to compare in anyway the QED to the Fisher Impulse AQ only results using a pulse delay of 7.5uS.
    • By Steve Herschbach
      I do what I can to foster competition that develops alternatives to the all too common VLF detector. There are plenty of options out there, but in my opinion they all weigh too much or cost too much. Usually both.   I envision people out there with a popular VLF metal detector for beach, relic, or gold detecting. These machines all sell for around $700 and weigh 2.5 - 3.9 lbs. Perhaps they would like to add a ground balancing PI (GBPI) to what they have. I think that for "normal people" with normal budgets a machine under $2K and under four pounds just makes sense. It would be more than twice what they spent for their VLF, and in this day and age there is no reason why a decent PI should weigh over 4 lbs. I am drawing the hard line at 5 lbs and refuse to ever buy a metal detector again that weighs 5 lbs or over. I am setting under 4 lbs more as an aspirational goal that I think can be achieved, but recognize that battery power and coils are key inhibiting factors in high power PI systems that May make sacrifices in depth necessary to get total weight under 4 lbs.   To clarify what I am talking about here, I should say that for many people a $700 VLF detector is a great place to start and in many cases is all a person ever needs. However, there are places where extreme ground mineralization and mineralized rocks (hot rocks) severely impede the performance and use of VLF detectors. Alternative technology to deal with these conditions has been developed, by far the most familiar being the Minelab ground balancing PI (GBPI) detectors. These differ from common PI detectors by having the ability to ground balance. Other brands have offered the Garrett Infinium (discontinued) plus Garrett ATX and the White's TDI models.   These detectors are used not just for gold prospecting but also by relic hunters, beach detectorists, and others who face challenges regarding ground mineralization and VLF detectors.   Frankly, in my opinion GBPI technology is largely maxed out. The main room for improvement comes now in better ergonomics at lower prices. This challenge therefore limits detectors to those that weigh under 4 pounds with battery included, and which sell brand new with warranty after discounts for under US$2000. Detectors need not be ground balancing PI models, but must offer similar ability to ignore mineralized ground and hot rocks that trouble VLF detectors. I am going to rate detectors as to their relative performance using what I call the "Minelab Rating Scale. Details here.
      1. Minelab SD 2000 - crude first version, very poor on small gold, excellent on large deep gold
      2. Minelab SD 2100 - vastly refined version of SD 2000
      3. Minelab SD 2200 (all versions) - adds crude iron disc, ground tracking
      4. Minelab GP Extreme - adds greatly improved sensitivity to small gold, overall performance boost.
      5. Minelab GP 3000 - Refined GP Extreme
      6.  Minelab GP 3500 - Greatly refined GP 3000, last and best of analog models
      7. Minelab GPX 4000 - First digital interface, rock solid threshold
      8. Minelab GPX 4500 - Refined GPX 4000, solid performer
      9. Minelab GPX 4800 - Released at same time as GPX 5000 as watered down version
      10. Minelab GPX 5000 - Culmination of the series, current pinnacle of GBPI prospecting machine technology.
      All Minelab models leverage an existing base of over 100 coil options from tiny to huge.
      I am a very practical person when it comes to detecting. I know all the existing models and options by all brands very well, perhaps better than almost anyone. This is the way I look at it is this. If I personally were to spend a lot of money to go gold prospecting for one month, and needed a GBPI detector, considering machines past and present, what would I get and in what order of choice? Put aside concerns of age, warranty, etc. just assume functioning detectors.
      Here is the issue in a nutshell. On the Minelab scale of one to ten as listed above, I would be generous in rating the White's TDI SL as a 2. Same with the Garrett Infinium which I will mention in passing as it is no longer being made. If I was going to spend a month of my time and a lot of money going on a prospecting trip, I would choose a TDI in any version over the SD 2000. I might go with a TDI Pro over a SD 2100 but I would have to think real hard about that, and when push comes to shove I would go SD 2100 were it not for the realities of age I said to ignore. A newer TDI Pro might be a better bet than a very old SD 2100 from a reliability standpoint, but again, this would be a tough choice. The TDI SL not really. In my opinion I would be shooting myself in the foot to go on this hypothetical trip with a TDI SL instead of a SD 2100.
      You see the problem now?
      The Garrett ATX fares better. I would rate it a 3, roughly analogous to the SD 2200 variants. Still an agonizing choice really and the ATX being new versus SD 2200 being old might again be the tipping point, but from a pure prospecting options perspective the case can be made that the SD 2200 might be the better way to go. The problem for this challenge is the ATX weighs way over 4 lbs and sells for slightly over $2000. The price is close enough really but the 7 lb weight is way off.
      That's it folks. That is reality. The best of the best that the competition can offer can only go solidly up against models Minelab has not made in years. I am not saying that to be mean or as some kind of Minelab toadie, that is my pure unvarnished opinion as a guy who is pretty well versed on the subject.
      Let's bring it all home. This person with the $700 machine really, really wants that under 4 lb, under $2K GBPI machine, but if they do their homework they discover that truthfully, they would be better off shopping for a used Minelab than what the competition offers new. With the TDI SL rated as a 2 the ATX in a much lighter box at under $2K is a solid win as a 3. A well designed ATX with standard dry land coils would look very enticing as compared to the GP series Minelabs. But Garrett refuses to budge!
      White's can certainly do something, anything to improve the TDI SL. A battery that lasts all day would be a good start. In the end they are limited by the basic single channel design of the machine. The SD 2000 dual channel design was literally the answer to and the improvement on the single channel technology used in the TDI, the basics of which predate the SD 2000. Still, White's currently owns the under 4 lb under $2K GBPI category so they have the first out of the starting gate advantage. Anything they do would at the very least just show they have not given up.
      The Minelab MPS patent that formed the basis of the SD series has expired. Not sure about DVT, which formed the basis of the GP series. Where is the competition? What the heck is going on here? Much gnashing of teeth and pulling of hair is going on here, that's what!!!
      That is my challenge to the manufacturers. Under 4 lbs, under $2K, on the 1-10 scale I am offering, what is the best you can do?
      The TDI SL as a 2? Really? Yes, really, that is currently the best of the best in the brand new ground balancing PI, full warranty, under 4 lb, under $2k category. You can pick up a 3.5 lb TDI SL right now brand new for $1049. The White's TDI SL takes the crown.
      Note that a challenger has a half pound of weight they can add to the TDI SL and still make the 4 lb mark, and retail can be almost double the $1049 of the TDI SL and still come in at the 2K mark. I therefore do not think my challenge is outright crazy.
      Hopefully we will see more competition in this wide open category soon. I have been beating this drum for years to no avail, but I do have reason to believe we are finally going to see more alternatives soon. I hope. Maybe? All I know is I have had it. I sold both my 6.9 lb Garrett ATX and 7.2 lb Minelab GPZ 7000 and am boycotting metal detectors that weigh over 6 lbs from here on out. I don’t care how well they work, I simply refuse to buy such heavy beasts from here on out. In the future I will support and give my dollars to companies that pay attention to and prioritize lightweight, more ergonomic designs.

      White's Electronics TSI SL metal detector
       
    • By Dan(NM)
      I had a guy approach me at the lake today who lost a 14K college class ring size 11. I told him I would spend time looking for it and get it back to him if I happen to recover it. I have a 10K college class ring I found this year(unable to locate owner) but, it's a 10K. On the Simplex, it reads 64-65, the Nox hits at 20-21 I'm wondering how much of a difference the 14K will read. Any help would be appreciated. Thanks.
    • By speedman2049
      Hello from Canada!
      Long time lurker here from Canada reading up on many many pages on here (and others) on detectors and needed some advice/user experiences that people have had (and thank you in advance as i appreciate any reply taking the time to do so!).
      This would be a first time detector for me and ideally i would like to spend around $400usd and can maybe stretch it to $600-800usd if i wait, although i'd really like ideally something in the $400 range.
      My primary use would be for small tiny gold nuggets in my area (~0.1g-~1/2g) mainly hunting placer gold in rivers/riverbeds, and some relic/coin hunting on the side if possible with coil swaps.
       
      A couple of detectors that made my short list:
      -Bounty Hunter Time Ranger (non pro) ~$300usd (Pros: comes with 8-inch search coil and 4-inch Gold Nugget coil   Cons: Operating frequency 6.6 kHz) Seems like it can get the job done and used for both gold nuggets and coin/relics, price hard to beat, only downside is the 6.6 khz on smaller nuggets i think.
      -Minelab Vanquish 440 ~$300usd (Pros: Multi IQ Frequency 5-40khz   Cons: Not specifically designed for nugget hunting, no small 4-5" coils) Also seems like it could get the job done with the v8 coil although more geared towards coin/relic, still with possibly playing with sensitivity and no discrimination could be a viable option and was thinking about this one heavily.
      -Fisher Gold Bug 2 ~700usd (Pros: 71khz frequency   Cons: Specifically designed for gold nugget hunting, high price, not multi versatile as not many coils) On the higher end of the budget with price, not really versatile in the sense that i can only really use it for nugget hunting, on the other hand excels at nugget hunting but that's all.
      -Minelab Gold Monster 1000 ~700usd (Pros: 45khz frequency  Cons: Pretty much the same as the Gold Bug 2) Again high end of the budget, same as gold bug 2 except lower khz but easier to use.
      -Minelab Explorer 2 ~300usd used! (Pros: 1.5khz-100khz, multiple coils  Cons: Discontinued, Not designed for nugget hunting) I found a user Minelab Explorer 2 that comes with a carbon fiber shaft, 10" coil, 7" coil, 2 battery packs! I think for the price it's a steal! I also read that although general consensus is that it can't do gold nuggets, however a couple people had tweaked the settings and were still able to pick up nuggets that were as small as 2grain (0.1gram) with small coils!
       
      Please let me know what you guys think would be a good fit, as well as any others that you can think off, and again thank you in advance for reading this and replying!
×
×
  • Create New...