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Willy

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Posts posted by Willy

  1. 21 minutes ago, Skullgolddiver said:

    I might be wrong, but just to be sure of the settings effectiveness, I believe that before to go on the field, this test should be done after those 10 minutes warm up...

    At that point I can be sure that the machine will react in a certain way with the knobs in a certain position...And I will hunt with peace of mind during future sessions...

    Great informations however...I just don't know how to be now...If sad, cause there's not yet a release time at the horizon or happy cause I'm gradually learning how to use this machine without even touching it...

     

    No

    This iron reject procedure should be made on the spot you are going to survey and not at home before going there. The ground type influences the results.

    The warm-up  does not changes the conditions as much as the ground.

  2. 38 minutes ago, phrunt said:

    So the QED is getting almost the same depth in it's lowest gain 1/10 in goldenoldies test than the AQ is in an air test on a nickel while using a significantly smaller coil?  Seems weird.  It does seem all the PI's are pretty equal.

    This last piece of Willy's post is also interesting, the same thing with the QED, takes it 10 or so minutes to warm up then you are meant to adjust settings and ground balance if necessary....  Similar components I guess.   See below also I'm hoping the "readjust" typo isn't in the actual manual 🙂

     

    This extract was indeed taken from an early version of the manual. I do not know if this 'tiny' mistake is still in there.

    In the certification document:

    3. US Nickel Depth min. = 15.5 inches (in factory)
    4. Gold Ring Depth min. = 16.5 inches (in factory)

    7. US Nickel Depth min. = 16 inches (air test)
    8. Gold Ring 18K, 2.7 grs, size 8, Depth min. = 17 inches (air test)

    Note the word 'min.' in the QC results.

    The QC tests are made on the PCB alone on a test bench and during the functional tests at the end of the assembly line by QC personnel.

    They expects a CLEAR SIGNAL response and the tests are made in a noisy (both EMI and external sound) factory, not in the field. The purpose of this test is to certify that the whole system gives its MINIMUM specs, not its MAXIMUM specs.

    They are not detectorists.

    A real detectorist using a good quality headphone would react on much less clear sounds.

    The real practice has proven that these specs are extended by one or two inches in fair ground and in the hand of a real detectorist.

    So, please do not jump to too early conclusions☺️😉

  3. That little nail in a capsule is indeed routinely  used for the iron reject tests during the functional certification of the Impulse in factory  but the main reason why it is joined in the package is to be used by the user as a common iron reference target when adjusting the tone/mute modes in the field before starting a session in disc mode.

    The operator manual defines the correct iron reject adjustment using that 'reference iron target'. This is the best procedure to get the most of the iron reject function. (see extract below)

    The capsule is there to avoid the nail to rust and react differently over time.

    5.7 REJECT Control

    The REJECT control determines the amount of iron rejection. It applies to TONE, MUTE, and VOLCANIC SAND modes.

    A high REJECT level also rejects high conductive targets like larger silver coins; rarely even gold items (such as a large heavy ring) can fall in this range. REJECT should be used only when there is an abundance of iron.

    REJECT is best adjusted with an example target you want to reject. A sample iron nail is included with the Impulse AQ Limited.

    1. Choose TONE, MUTE, or VOLCANIC SAND mode.

    2. Set the REJECT control to 0 and the ATS control to 8.

    3. Put the reference iron target on the ground in horizontal position.

    4. Swing the coil over the target at a height of around 3 inches while slowly increasing the REJECT control.

    5. Stop when the nail responds as follows:

    a. In TONE mode: the iron response is mostly low tone with some minor high tone mixed in.

    b. In MUTE mode: the iron response is mostly silent with some minor high tone breaking through.

    c. In VOLCANIC SAND mode: the iron response is fully silent which is necessary to reject volcanic ground.

    6. Optionally, test a US nickel to verify that it gives a high tone.

    In setting up iron rejection, both the ATS and REJECT controls affect each other and should be mutually adjusted to achieve the desired rejection responses.

    It is highly recommended that rejection is set in the field using test targets. (see Expert REJECT control)

    NOTE: The REJECT feature of the IMPULSE AQ does not function in the same way as the discrimination control on a VLF detector. It provides variable audio masking of iron targets as well as high-conductivity targets. Also, unlike some PI detectors, there is no target hole.

    5.8 Expert REJECT Control (ATS + REJECT)

    1. Choose TONE, MUTE, or VOLCANIC SAND mode.

    2. Set the REJECT control to 6 and the ATS control to 0.

    3. Put the reference iron target on the ground in horizontal position.

    4. Swing the coil over the target at a height of around 3 inches while slowly increasing the ATS control. (Your setting is normally arrive near the position 8, between the position 7 and 😎

    5. Stop when the nail responds as follows:

    a. In TONE mode: the iron response is mostly low tone with some minor high tone mixed in.

    b. In MUTE mode: the iron response is mostly silent with some minor high tone breaking through.

    c. In VOLCANIC SAND mode: the iron response is fully silent which is necessary to reject volcanic ground.

    6.Finally refine your setting, decrease the REJECT button to obtain an iron response low tone with some minor high tone mixed in.

    7. Optionally, test a US nickel to verify that it gives a high tone.  

    In setting up iron rejection, both the ATS and REJECT controls affect each other and should be mutually adjusted to achieve the desired rejection responses.

    It is highly recommended that rejection is set in the field using test targets.

    NOTE: Your IMPULSE AQ takes about 10 minutes after start up to stabilize in temperature. Consequently after this time it is recommended to re-adjust the settings slightly.

  4. On 7/13/2020 at 4:40 PM, Steve Herschbach said:

    That nails it, and only time will tell if the components used are up to the long term task. So far, hand built, carefully tested detectors, and a roughly 10% failure rate.

    The main heat generators are the MOSFET and the damping resistor.
    The MOSFET has been carefully selected for its low RDSon and  to sustain the high flyback voltage.

    Just the JOULE's law (W=RI2), large current even  in low resistance--> heat

    This is the price to pay for a powerful PI with the current technology.

    The switching power supply itself does not generate heat.

    Thus, no worry about the long term reliability on that subject.

  5. 10 hours ago, pjrough said:

    What is the turn down voltage for AQ?

    Building a battery pack for my waterproofed minelab etrac, I realized that it switches off at 9v, so no BMS was actually needed for my 3s lipo pack. 

    I am not a huge fan of pulling battery out of the  housing for charging them, so detector is fitted with 4 pin ip68 connector which is used for charging/balancing. (Blue cap socket is the connector, see photos below).

    So if AQ's lower voltage is 10v, there are li-ion cells with allowed low voltage of 2.5 volts, thus balancing can be moved to the charger.

    Or another way round, the AQ was designed for lithium battery, so maybe there is some sort of protection circuit build in the detector already. 

     

    Adobe_20190628_161610.jpg

    Adobe_20190614_212528.jpg

    It was designed like that but there is no protection circuit in the enclosure, it was inside the battery pack.

  6. 9 hours ago, Joe Beechnut OBN said:

    Tony I'm so desperate for a small coil I'm ready to take the little 8 inch off of the barracuda and try it on the "AQ"..😬

    It would probably more or less work BUT you will loose quite a few inches and possibly loose a few µsec of pulse delay.

    The design of the Impulse coil has been specially studied to cope with small pulse delays and EMI protection and still kept light.

    Its production in series was carefully setup in order to generate constant specs in values of R,  L and C. with thorough measurement  at various phases of the production line. The measurement data is recorded for statistical reports.

    This is unusual in the coil production of the detector industry.

  7. 11 hours ago, midalake said:

     

    Do I hear 9 1/2.........9 1/2, 9 1/2, going going........GONE!!!!   [8" is a little small] 

    The ideal coil would be made of a flexible material like rubber (or chewing-gum!!) so that the user could change its diameter at will to make it perfect for all environment cases. In this case, you could have your own perfect coil, 12.5",12",11.5",11",.... down to 2"!!!

    Sadly, this is not (yet) possible with the current technologies😢😢

  8. Putting things straight about  batteries (specially Li-Ion) for the AQ (or for any portable device)

    Three different cases:

    1. Independent battery cells 
      •  They are charged in parallel, the charger takes care of each separately in terms of current and voltage, automatic balancing
        1. Protected cells (a BMS circuit in EACH cell) These cells are slightly longer than the non-protected ones, the BMS is at the top.
          • Highly recommended!!
        2. Unprotected cells
          • NOT RECOMMENDED ( no protection against over-voltage, over-charging, over-current including short-circuit, thus, potential fire and explosion due to the Lithium)
    2. Battery packs (A BMS circuit integrated in the battery pack)
      • For all the certified battery packs, a single BMS takes care of the battery cells separately. The charger connects to the BMS and not to the battery cells. The discharging current and voltage are defined by  mixed configurations of nSmP (n Serial Cells to increase voltage, m Parallel cells to increase capacity)

    The initial design of the AQ was using a LI-ION BATTERY PACK (with integrated BMS) permanently sealed in the battery pod.

    Due to certification problems and high costs, this technology was replaced by a Ni-Mh pack which does not require as much care for airline shipping

    The final AQ version and the GOLD version will be shipped with good quality protected Li-ION battery cells as defined in above case 1.1.
    It will not be possible to use the SHORTER non-protected cells.

  9. 13 hours ago, Joe Beechnut OBN said:

    Yes.......... I would be giving up some, my guess is about 4 inch's but the amount of noise from a small coil would be so much less in the rough salt water it will make a huge difference. So you figure I get 19/20 on a nickel...it would go to 14/15..but then again we are in un-charter territory could be better.

     

    In the VLF world, it is generally admitted that the maximum detection depth is directly proportional to the coil diameter. It is evaluated at a depth about equivalent to the diameter for a concentric coil.

    In the PI world, the equation is probably different but still directly proportional for the same target size, shape and material.

    The detection range is a cone sticking out  under the coil.

    A large coil generates a longer (thus, deeper) cone but its tip  is also larger making the pinpointing more difficult.

    A smaller coil is better adapted for highly ferrous-polluted ground because its more precise detection cone

    Real experiments in real ground and sea water will tell.

  10. 4 minutes ago, Compass said:

    "This will possibly be offered as an option to the LTD version as well."

    If different coil size options are eventually offered on the Limited AQ it may be a difficult decision for some of us. Most of my beach hunting is done in the wet sand and a few inches of water when the surf comes in. My first thought would be to go with the 12.5" coil for the maximum depth but an 8" coil with that short pulse delay could be a dynamic combination for the small gold.

    Indeed.

  11. 26 minutes ago, Compass said:

    Joe, I thought that the main reason you liked the AQ was for its depth. Wouldn't you lose some of that depth with a smaller coil? 

    I just re-read some previous responses and my guess is that one may have to trade off a little depth for less noise and better coil control. 

    Smaller coils are easier to swing in water and in rocky grounds.

    It also better picks up the small targets and is easier to pinpoint.
    However, the detection depth is indeed reduced. Again, you can not have your cake and eat it.

  12. On 7/10/2020 at 12:54 AM, Joe Beechnut OBN said:

    Since no one picked a 9 inch............... I'll call out for that, but at this point I'll take a 8--9---------10 is pushing the limit on swinging the coil in the water. I've noticed that it's hard to get the 12.5 up to speed in rougher waters. And with a smaller coil there will be a lot less resistance...........noise.........and better coil control......So 8 or 9 for me...

     

    I can tell you that the AQ will get a 8" coil. The GOLD will also have one (yet not interchangeable, different number of turn!!)

    This will possibly be offered as an option to the LTD version as well.

    There are already a few of them (as prototypes) out in the wild under field testing

  13. 4 minutes ago, Steve Herschbach said:

    Willy, I want to personally thank you for your calm responses to my sometimes pointed questions. I am quite grateful to have you here putting up with me and providing such great information! :smile:

    No problemo😉

    Pointed questions or remarks can only generate progress and new ideas. 

    I know the whole history of that project from its beginning when it was still named 'Manta' back in 1990.

    Since then, Alexandre and I have worked in closed team complementing each other with our respective technical backgrounds.

    I still keep in close contact with the Impulse project  (and with El Paso) while working on my own project(s) and I am happy to answer any technical question posted on THIS forum if it does not infringe the NDA I have signed with FTP.

     

  14. 2 minutes ago, Skullgolddiver said:

    I perfectly remember this thing on the Excalibur battery connector, never been a big problem with some good gel grease ...Now...Using a metallic connector installed from the source (FT plant), I think the connector electrolysis phenomenon can be on the outer part of it right ?

    So I see a temporary solution : heat shrink tubing right around the end of cable and connector...

    Yes, it stays outside of the connector but that was deemed to be unbearable by the reports of early testers. The change of connector resulted in it sensitivity to local capacitance variations. (You can't have your cake and eat it )

    There was even an electrolysis effect on the surface of the metallic upper shaft with a nasty looking result. This was also replaced by the current plastic-made upper shaft.

  15. On 7/7/2020 at 6:59 AM, Joe Beechnut OBN said:

    Early on I see the Halo of targets in the threshold of the "AQ" doing airtest..... so I've been playing with the settings to see if I can pull up more of the audio of them when out hunting in the water. Jim and I have hunted together before, a very good "old beach" hunter. 

    Video of those changes in the threshold Jim speaks of....

     

    This is the recipe to catch the deepest targets.

    The good stability of the Impulse and its variable pitch audio coupled with a good-quality headphone (with well external sound-isolated earmuffs) enable the user to capture those little variations of sound in a threshold adjusted to slight feedback.

  16. 1 minute ago, Skullgolddiver said:

    Feel free to laugh of my try to find a solution 🤣as it might sound crazy or at least stupid...

    Can't be possible to create an outside connector shielding sock with a 3m shield tape? Something like a cable/connector glove to avoid direct saltwater contact with the area? Is it something to be necessarily fully waterproof?

     Nothing to laugh at. This is the way to make good  brainstorming.

    In order for that to be effective, it would need to be electrically connected to the shield of the cable AND be protected from the sea water contact. Difficult to implement and ugly-looking.😢

    If you do not mind the consequences of the electrolysis on a metallic connector, you could use one to replace the plastic-based but Quid of the Warranty?

  17. 9 hours ago, Steve Herschbach said:

    Can't argue with that. So how did this make it off the drawing board....

    fisher-impulse-aq-ltd-cable-details.jpg

    This design was a result of the initial requirement of battery packs (then large capacity Lion type)  to be exchangeable and to be able to have a double length (and capacity) battery pack option with an added possibility to carry it hip-mount with a longer battery cable.

    This is the preferred configuration of Le Jag.

    True, this power cable and connectors sticking out at the back are not looking nice and are sensitive to shocks.
    I think it is essentially due to the long stress reliefs added later on to the two connectors.

    These connectors have shown their limits in multiple mating/unmating and in their IP specs in terms of water pressure resistance

    Another type of over-molded power cable with different types of connectors is now being thoroughly studied and tested. This will probably enable the depth specs of the Impulse AQ LTD to be increased to a market-standard values.

    If the tests are finally successful, this cable will be shipped with the next orders of LTD and probably will be shipped by FTP to the existing users.

  18. On 7/8/2020 at 12:40 AM, Steve Herschbach said:

    So based on the above, sort of like this, but the upper rod probably a little thicker.

    fisher-impulse-aq-metal-detector-version-2.jpg

     

    Only a few mills more in diameter. The battery compartment is an alu tube  enclosed inside a shaft extension and protected from the contact  with sea water in order to avoid any electrolysis effect between metals of different natures.

    The slight difference in diameter has required a new arm rest design (and tooling).

  19. 7 hours ago, Steve Herschbach said:

    First off, I want to point out that what I am about to describe is not uncommon with high power detectors that have a coil that can be disconnected. The only way to really eliminate the problem is to hard wire the coil, which is another reason for why this option is chosen by so many manufacturers of underwater metal detectors. The White's TDI Beachhunter is a good example. The problem has its root in coil capacitance and the high voltages involved, and the difficulty of getting good shielding using a removable connector.

    If the Impulse AQ is submerged halfway, so that the water level is anywhere in roughly the area indicated in the photo below, you will get continuous false signals. Just holding the unit stationary in the water at this level will cause signals as the water moves around the connection area. If you are not aware of what is happening it is every easy to mistake this for electromagnetic interference (EMI).

    The problem is worst in the Tones mode, which I just happen to be using a lot. It is accentuated by a short pulse delay, high sensitivity settings, and low ATS settings. If you want to reduce the false signals, here are some solutions:

    1. Use the All Metal or Volcanic modes instead of Tones
    2. Increase the Pulse Delay to 9 or higher
    3. Reduce the Sensitivity to 4 or lower
    4. Increase the ATS to 8 or above

    Or some combination of the above.

    In practice this only occurs when wading, and only at a certain depth. My solution was simply to stay either deeper or shallower. This does leave a strip or area unhunted. You can either switch the settings as suggested above, or do something to change the height. Like hunt that strip with mask and snorkel, for instance. 

    Anyway, hopefully this is put in the manual as it is something inherent in the operation of the detector, and can drive you nuts if you run into it and do not know what is going on. It took me several hours of detecting to put two and two together, and it was then confirmed that yes, that is the way it is.

    fisher-impulse-aq-coil-connertor-false-signals.jpg

    The high voltage and short pulse delay of the Impulse are requiring a strict shielding of all the parts subjected to the pulses (coil, cable and connector).

    That effect is due to the small gap of continuity of the cable shield between the the male and female connectors and the changes of capacitance coming from the conductive  water level variations.

    It was for that reason that the coil connector was initially made of metal in order to keep the continuity of the cable shielding up to the inside of the enclosure. (Same supplier, other item)

    Field tests in the sea water had shown a bad electrolysis effect on its body giving it a nasty look.

    A plastic connector had to be used for the AQ.

    The GOLD version will even require more attention to this capacitance effect as it will have a much  shorter pulse delay, it will get an (expensive) stainless steel connector to keep a perfect shielding.

     

  20. 15 hours ago, Joe Beechnut OBN said:

    My Opinion...........They better move up with something more modern....more of a Carbon fiber look. ....And I don't think four 18650s are going to do the job, I'm thinking more (4) 26650's inline ..same battery the MDT uses..the new Fisher needs at least 8 hours hunt time to cover these young guys and who have endless energy, and not have to walk back to the car to change the batteries after 5 hours....And for the Old Goats like me have a insert that holds the (4) smaller (less weight) 18650 batteries.....I need to work for these guys....second though I enjoy hunting more.

     

     

     

    Impulse 2022 AQ.jpg

    Designing a new mechanical system is a 'bit' more than tweaking a picture with Photoshop. This indeed looks nice BUT one also has to care about a lot of 'small' details like the costs and complexity of the tools to mold these plastic components and the way to assemble them to be sturdy and waterproof while keeping a light weight.

  21. 5 minutes ago, schoolofhardNox said:

    Plenty of nails everywhere in the USA :rolleyes: The old shipwreck nails in my area are bronze I believe. Probably the 1700's and up. We can never totally get rid of nails, the best we can do is limit how many we pick up. Deep nails can be 15, 18, 24" etc deep. they sound very faint at that depth, just like a deep coin can.

     

    You would never be able to discriminate out BRONZE nails. You will have to live with them!!

  22. Joe,

    Do not take any attention to the nasty remarks. Some people would never be happy with anything you could ever do.

    That is also the experience of Alexandre when making video.

    We are ALL very thankful about your many tests, very well documented, convincing and with  clear audio. You are doing it like a pro.

     

    I suggest you just to follow your own learning curve and not react with video coming from endless forum requests.

    If you make video of your own tests, it's already very informative for everyone.

    Also, do not take too much time on that. Go detecting as Steve is doing. If it happens that you find GOLD on the way and there is a video showing it,  it is the best convincing proof that the AQ is working well and that you strat mastering it.

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