palzynski

Yes I agree with you El Nino , static tests on bed tests are important , because you can compare with them different machines in the same conditions : same ground , same target … It is very important to keep the same conditions during the time , and not change the ground or change the target . If you follow this rule then the depth measurements are very reliable and repeatable . And I finally ended to the conclusion that the VLF performances are very similar whatever the brand is, for a given coil size and frequency . For example 12inches max depth on a big coin in my local low / medium mineralized ground for an 11inches coil at 5 or 8khz. Another thing I could see with these tests that the VLF detectors do not progress any more in terms of depth performance , this is why I am very interested by the new "AQ" technology. Of course field tests are essential, Dewcon I agree with you . But be careful with user "feelings" , because this is a very subjective way to analyze the things , and I rather prefer a "scientific" approach by doing measurements , then field tests. For example once a seller asked me to test a detector , he told me that the machine could see a coin at 16inches or more depth. Finally I tested the machine on my "boxes" , and at the end the results were very similar to the other machines , no improvement at all. He was just "psychologically" convinced that his machine was better than the others , but in fact it was not the case ...

HI , it is always the same with detection measurements , they are very subjective if done on the field with approximate measurement tools. If you want to have an accurate idea of the performance of a machine , you must test it on static dedicated bed tests , with always the same conditions , and not on the field because the conditions ( hygrometry ) can change depending on the season. We have discussed on this with El Nino and Alexandre in an other discussion on this forum , see below . On my own test ( a big box filled up with ground ) I think I have an accurate idea of the max depth of a VLF machine. I have tested a dozen of VLF detectors since several years using always the same bed tests , and actually the max depth is always the same around 12 inches on a big coin say 10grams using a 12inches coil size. This test is very reliable and repeatable. It would be very easy for me to test the AQ on this bed test , I would evaluate the difference between a VLF machine and the AQ in a few minutes ... Oh yes I have also a box filled with sand mixed with salt water to reproduce the see beaches conditions , I mean the French ones, not the volcanic sands like in Hawai ... So if somebody wants to send me an AQ for measurements , do not hesitate … 😊

Thx for the info El Nino . Actually I have ordered a vanquish 540 plus a V10coil because this medium sized coil is NOT available for the Nox. On the Nox you have a very small 6 coil and a 11 big coil , and nothing between them , I do not speak about the bigger 15 one which is unusable for what i am doing , coin shooting in often iron trashed soils . It is strange that ML does not propose an equivalentof the V10 coil for the NOX , considering that this intermediate size is a standard for all the other detector manufacturers , look at XP for example ...

https://www.metaux-detection.fr/xp-orx-disque-circ-22cm-hf,fr,4,TEST-XP-ORX.cfm

And for info , an example of a test done for a French shop / Chateau Numis in Château Thierry North East of France . Here the detector tested is the XP ORX with a 22cm HF coil. The test includes static tests on boxes and field tests at different locations ( In French only sorry ) ...

Hi Rick , if I understood well, you are the owner of an AQ , did you do some tests with it ? thx , Alain

18inches on a coin with a GPX I did not had these results it was rather 12/13 inches for me , this with the standard 11coil. But I did these tests a long time ago , 10 years ago and perhaps I should redo these tests. Also there is the GPZ that seems to be more powerful than the GPX but its price is astronomic at 9000euros and no iron disc at all ... Alexandre , yes it is not simple what you are doing , I thought that this was "just" electronics but it is more than this , so it takes times for the machines to be produced in an industrial way, this is normal. I am looking forward to see the AQ on the field during the coming weeks ....

Ok 2000 kgs impressive , I have almost broken my back when filling my "little" 50kg or so boxes … 🙂 Otherwise yes I agree , for high mineralization testing you have to use a big volume of ground. For low mineralization I think my boxes work quite well because the air mineralization is not so far from the low mineralized ground I think … I imagine that you will fill your 4 holes with different levels of mineralization true ? With these tests you will have a precise and repeteable idea of the performances of your machines . The only thing is the hygrometry of the ground which could change the results depending on the season. I have not this issue with my boxes which are covered with a plastic top all the year very interesting discussion , thank you for your post Alexandre ….

Yes Alexandre and Steve , I agree with you , the more it is mineralized the more difficult it is to go deeper this is what I wanted to say , probably I was not clear in my prev post. Thank you Steve for the diagram , actually I did some measurements with a GPX4500 a few years ago and I could not get much than 13inches on a big coin in the air , a little less in my low mineralized ground. And you are right Steve this is not far from a VLF machine which takes it at 12inches But if we come back with the Manta video we are not talking about 13inches on a coin , but about 20inches which means a 54/100 increasement! Even if there is a loss due to the mineralization , I would be happy with "only" 16 inches in my moderated mineralized ground, this with a correct level of iron disc of course. It looks like the AQ has something special to go so deeply, probably the delay to 7micros however I am not a specialist. thx again for your infos Alexandre and Steve For info my bed tests here :

The depth performances of a VLF increases while the ground mineralization decreases. Better explained this way ...

From a video that I saw it was a Manta if I remember well , it was able to detect a 2euros coin at 50cm ( 20inches) in wet sand of a sea beach , this test was done on a beach of Northern France . With a VLF such a coin is taken at max 30cm ( 12inches ) in moderated mineralized ground from my own tests . So you mean that a PI like the AQ could not go deeper than 30cm on such a big coin in moderated mineralized ground ? I would be quite surprised with this because a VLF works exactly the opposite way, the depth performances of a VLF decreases while the ground mineralization increases. Nevertheless I have no real experience of PI prospectng apart a few tests done years ago with a GPX4500 , you know better than me on this subject … Thanks for your answer again ...

And below my own bed tests : 2 plastic boxes filled up up with ground , and a coin put under each box, no iron under the boxes : - Box 1 ( the closer one on the picture ) : . 15cm of dry moderately mineralized ground / a 3grams bronze roman coin put under the box - Box2 : . 28cm of dry moderately mineralized ground /a 10grams copper coin ( 10centimes napoleon 3 ) put under the box These bed tests are very simple and very reliable, the results are always the same whatever the season. They push the VLF detectors at their limits , either for the 10grams copper coin at 28cm or for the smaller roman 3grams coin at 15/16cm. When I test a new detector these tests help me to find the best settings before going on the field. The other picture shows the Nokta Simplex+ that I am currently testing with its 28cm coil in action on Box2. As the other machines , it detects the 10gr copper coin but it is the maximum and it cannot go deeper for this target . And its limit in the 2nd test is 15/16cm ( the small 3gr bronze coin ) like the other VLF machines again . Just wondering how the AQ would perform on these tests ….

and in dry low/moderated mineralized ground ?

Ok Steve but I think that your initial idea is good , such a detailed chart is very interesting because it is very simple to understand so I think that fisher labs should provide one in the AQ user manual , so that people know exactly what the AQ can do ( or not do ) . This will avoid a lot of misunderstandings and frustations . Also from what I read here the AQ is a new generation machine that works differently from the previous ones and everything must be very well explained. BTW unfortunately for me , it looks like the AQ is not adapted for moderated mineralization ground prospecting ( I am a coin shooter, inland ) , so I will have to wait the future Fisher RELIC machine , I hope it will come soon because the VLF machines do not evolve any more in terms of depth performance since several years and I need some extra depth :-) ... Thanks for everything , Alain

Steve , back on your diagram page 6 ( the modified version of a Minelab Equinox chart for the AQ), there is something which is not clear to me with this chart : In summary , this shows shows the PI detection scale like this, from left to right : 1. Small ferrous / 2. AQ detecting range / 3. Iron nails , screws / 4. large ferrous I do not understand why there is an "iron gap" between 1.small ferrous and 3. iron nails, screws. Why no ferrous in this 2. AQ detection range? There should be some ferrous of intermediate sizes between 1.small ferrous and 3.iron nails,. And no void as it is indicated in the chart. And at end I think that the AQ will accept some ferrous , just my opinion … thanks for your answer , Alain

El Nino your post is very interesting thanks. On my bed tests I have 70% reach , for example on a french 10cent Napoleon 3 10grams copper I can detect it at 40cm in the air , and it reduces to 28cm in the ground, this , it is true for all brands of machines that can run a low frequency under 10khz. For example 5khz or Multi with the equinox. So this is my challenge , it is very simple , go deeper than 28/30cm with a 10C Nap3 coin …. Actually I am wondering it the impulse aq can be used on moderated mineralized soils. If this is possible , then an AQ will probably go further that 30cm in the ground . But from what I read in this forum it looks like that the AQ has been designed only for salted beaches . But wait and see , the real tests will answer to the question ...

Hi Yes I agree with you Alexandre , a serious MD test must be a blind test. If the tester knows where the target is buried and the kind of target buried , in most cases he will tell that he detects the target, even its detector cannot do it. As you said he THINKS that he detects it but it is a kind of psychological "auto suggestion" process ( sorry it is in French ) . The MD tests must be done very scientifically with a very strict procedure as you have done above . Doing this with many detectors of different brands on my own bed tests , I arrived to the conclusion that the max detection depth for a VLF detector in moderated mineralized ground is always around 28/30cms for a 10Centimes napoleon3 ( 10grams french copper coin ), no more ,whatever the detector brand is . Tthis is just logical because the electronic/electromagnetic physical laws are the same for all the machines.... The last test that I did was with the Nokta Simplex+ , and the result was again 28cm on this 10C Napoleon coin. By the way I am looking forward to see a Fisher PI coin/relic machine coming after the impulse AQ and the Terra , if this is technically possible .And I am looking forward to see a machine beating the 30cm depth on the 10Cent Napoleon 3 ( with a very good iron disc of course ) , I have never found one up to now …. thanks , Alain

Hi , yes I agree with Luis , tiny bits of iron like the euro 5cent above and very small nails will not be rejected by the AQ if I understand well. Could you confirm this alexandre , because those very small nails/bits of iron are not shown in your diagram. Thanks … Alain

thanks and happy new year … Alain

Hi , I am Alain from France , very interested by this discussion on the new fisher impulse aq technology , even if I am more a coin/relic hunter than beachcomber , I live in the north east of France and I detect in low mineralized ground. First thanks very much steve/alexandre for the pi/aq discri informations , I now understand better how it works . So it looks like even the last impulse aq will not eliminate ALL the ferrous targets at the same time ,keeping good targets like a VLF does. In France there is everywhere a very dense iron trash density coming from more than 2000 years of human presence. And then it is very important that the iron disc is excellent, say perfect. It is the most important thing for our areas I would say. The problem with coins is that they can be of very different sizes , for example the roman coins we have over here scale from 1g to 30g, with possibly different metals. So it is not possible to use a discri by size like the one that is used by the AQ. Actually I am a little disappointed considering the amazing depth performances of the AQ …. I know that the AQ is not designed for coins but for gold rings in wet sand. But I have read somewhere that a PI relic/coin machine was planned by Fisher, based on the AQ techno , so I am wondering how the iron disc will be managed with this new relic/coin machine ....