You need to pick up a copy of “Inside the Metal Detector” by George Overton and... Carl Moreland!
Fisher Impulse AQ detector update
- Thread starter tnsharpshooter
- Start date
You need to pick up a copy of “Inside the Metal Detector” by George Overton and... Carl Moreland!
dewcon
Quality Control Expert
I think any machine needs to prove its self ....... skepticism most certainly when something NEW hits the streets that exceeds what we know from past PI machines. Here we have a machine running quietly at 7uS in salt water...... with an unheard of depth increase....... designed for the beach to find specificly gold....... AND as a PI will disc out iron and high conductors something others PI arent that good at. Many were skeptical of the Nox...... it had to prove its self..... even the CTX because of cost took some time to really sell. This is a pricy PI..... what almost twice as expensive as many we had been using. Now we have delays..... does that not raise an eyebrow? ....... so is it not reasonable to be a bit skeptical? That doesnt me we are calling anyone anything..... it just means until the masses test this machine its unproven.
Do you guys remember when Dean Kamen invented the Segway around 2000 but no-one knew what it was going to be or how it was powered. There was talk of it being a Sterling engine etc. I found it very interesting and cool that all of a sudden people were talking of invention possibilities and how something unheard of could be done. In a smaller scale we have this AQ. We know it has this fast sample time but we also know from experience that depth and discrimination with a quiet background is new. We now wonder what could it’s design be doing different to achieve this. Competitors realize the threat and surely are working on achieving equal or better performance. It’s all good.
One happy result of the seemingly endless process of getting the mechanical package, production process and certifications done in El Paso is that Alexandre has been constantly pushing the boundaries of what the AQ is capable of. In the MANY months of slow progress towards full production, he has made multiple improvements in circuitry etc., resulting in a series of progressively improved boards, culminating in the released for production version.
Here is part of an email I got from him late last year as a result of asking him to comment on statements on another forum that there was no way a PI could operate at 7microsec. delay in salt water....
“I have reduced noise by 90% with a new electronic system (he is referring to the issued for production version) and I have reduced variations due to seawater conductivity. A variation in conductivity due to salt at 15µs of pulse delay on a FOSTER (the TDI is of course is an Eric Foster design) is equivalent to a variation at 8 µs on the IMPULSE AQ in terms of stability and salt conductivity compensation.”
Other results I am aware of as a result of this continuous evolution of the design are - reduced depth penalty for using higher levels of iron ID, expanded range of low conductor acceptance to include higher carat gold acceptance when using iron ID and a completely new mode of operation for Volcanic Sand and other extreme conditions which would totally shut down a VLF and many PI’s
Here is part of an email I got from him late last year as a result of asking him to comment on statements on another forum that there was no way a PI could operate at 7microsec. delay in salt water....
“I have reduced noise by 90% with a new electronic system (he is referring to the issued for production version) and I have reduced variations due to seawater conductivity. A variation in conductivity due to salt at 15µs of pulse delay on a FOSTER (the TDI is of course is an Eric Foster design) is equivalent to a variation at 8 µs on the IMPULSE AQ in terms of stability and salt conductivity compensation.”
Other results I am aware of as a result of this continuous evolution of the design are - reduced depth penalty for using higher levels of iron ID, expanded range of low conductor acceptance to include higher carat gold acceptance when using iron ID and a completely new mode of operation for Volcanic Sand and other extreme conditions which would totally shut down a VLF and many PI’s
beachrumbum
Senior Member
If this machine does what it is claimed to it will obsolete a lot of other machines. Why would I want to be swinging an excal or nox if dew has a magical gold sniffer on the same beach? To stay competetive I would have to have one barring fresh drops only. The only thing I see stopping every beach hunter from having one (if it performs as told) would be the price point.
dewcon
Quality Control Expert
Well price yes.... but there is going to have to be some positive buzzzzz. Otherwise Dew is still going to have THE gold magnet for months. It’s kind of like what will motivate others to buy? I think I’ve got the ticket now with the MDT on my beach yet there are very few around. Yet.... if the gold ain’t there it ain’t there..... an no machine may change that on some beaches
Every time a new detector comes out the same thing is said... They said that about the Nox and yet it hasn't made anything obsolete.
No way I would ever get rid of my Excal or any other beach detectors I own..
That is exactly the plan. And after that a nugget machine.
Now the nugget machine will face much stiffer competition from Minelab, but I think it will do fine.
Meanwhile - “Vamos a la Playa” - let’s go to the beach!
https://youtu.be/1_zgKRBrT0Y
i think this ought to be the first place I take my AQ - the “finds” might be remarkable!
Now the nugget machine will face much stiffer competition from Minelab, but I think it will do fine.
Meanwhile - “Vamos a la Playa” - let’s go to the beach!
https://youtu.be/1_zgKRBrT0Y
i think this ought to be the first place I take my AQ - the “finds” might be remarkable!
beachrumbum
Senior Member
Dew, your beach gives me the mumbles 98% of the time I am there. Makes no difference what machine I use.
Now that I think about it, I have to unlock that beaches secrets before the year is up. 
You want to see some gold Rick... go to Cartagena Colombia the chains guys wore down there looked like they were bought by the pound... the jewelry the tourists flashed was amazing and I had no detector with me
dewcon
Quality Control Expert
Everyone that hits the beach thinks they are going to dig $5000 worth of gold a month. There are some skilled hunters now days they can pick a beach clean. Add slim picked on people loosing stuff and I hear ya on the mumbles
Never too old mate - too lazy maybe - but never too old.
90 is the new 60. When I was a kid in the 50’s my great aunts and uncles were probably in their 70’s - they were OLD. They no doubt felt old - they certainly looked and acted old.
My wife plays tennis regularly (she’s 60 something) with 80 something players who more than hold their own. A friend of ours is in her late 80’s and she regularly wins gold medals at senior swimming events.
Dead is dead - but everything else is what you put into it!
90 is the new 60. When I was a kid in the 50’s my great aunts and uncles were probably in their 70’s - they were OLD. They no doubt felt old - they certainly looked and acted old.
My wife plays tennis regularly (she’s 60 something) with 80 something players who more than hold their own. A friend of ours is in her late 80’s and she regularly wins gold medals at senior swimming events.
Dead is dead - but everything else is what you put into it!
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TreasurdiggrNY
New Member
- Joined
- Mar 22, 2006
- Messages
- 29
Won't make my Excalibur obsolete, but a clean up tool for areas with deep Gold like today's
Little gold ring was about 18 inch's down...only reason I found it was I was digging a questionable target, which I ended up getting out of the hole and not realizing. The gold ring was deep below the junk target.............. then Boom.......... a foot away..... another gold, back to back golds. All to deep for the excalibur but not for the "AQ"
Waiting but not setting......
Come on "AQ"
Little gold ring was about 18 inch's down...only reason I found it was I was digging a questionable target, which I ended up getting out of the hole and not realizing. The gold ring was deep below the junk target.............. then Boom.......... a foot away..... another gold, back to back golds. All to deep for the excalibur but not for the "AQ"
Waiting but not setting......
Come on "AQ"
Attachments
Little gold ring was about 18 inch's down...only reason I found it was I was digging a questionable target, which I ended up getting out of the hole and not realizing. The gold ring was deep below the junk target.............. then Boom.......... a foot away..... another gold, back to back golds. All to deep for the excalibur but not for the "AQ"
Waiting but not setting......
Come on "AQ"
Wishing won't get it out any faster
I like the post above you better.. its too funny... that guy was sitting on the couch was waiting for the Pulse Devil as well... the AQ took its toll on him Good job on the gold Joe.
You get first prize - I’m sending this to Tim Mallory and Mike Scott at First Texas Products (Fisher)!!!
beachrumbum
Senior Member
I never expect any set amount of gold a month, I do alright with the finds I do make. I’ve scored some nice on that beach. It’s just not as regular as I would like. I recall reading of your troubles with it also. It is a beach that is pounded to death. If you mean gridding by being able to clean a beach, if I griddled as much as everyone else, no one would want to go behind me, I am a meticulous and slow gridder, I can cross hatch with the best of em too
but lucky for every one it upsets my adhd and depending on my mood I would much rather find a productive hole if at all possible.
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TNSS over on “forum D” was bugging me over the depth of the AQ in discriminate vs in all metal. I have been collecting and reviewing all my stuff on PI detectors for a couple of weeks now to put together a PI intro for AQ customers in the “great bye-and-bye” when it goes on sale.
so I sat down and wasted a few hours trying to explain what I THINK I know about the function of the AQ’s iron ID function. In spite of having had my hands on three different ones since October ‘18, I never got far enough along with any of them to really document actual controlled results in the ground. Anyway, if you want to ruin your afternoon or get a headache - press on....
As far as Tone ID at depth, first remember that in all metal, all targets return the same high tone. I will now try and explain the discrimination function and its results.
Now if the question is do the ID modes of multitone and mute provide the same depth of detection as the all metal mode, the answer is no. The depth difference has been progressively reduced as the development of the AQ went on.
The the depth penalty is due to the action of the discrimination system. the discrimination is achieved by analyzing the decay of targets return signals over time.
WARNING - I am not a physicist or an electronics engineer. The following is based on what I believe to be correct based on several years of studying PI detectors and the information Alexandre has shared on various forums and in private communications between him and I.
Pulse Induction detectors do their target analysis in the time domain - that’s why Whites called the TDI by that name. A strong current is created in the coil which creates a magnetic field. This is transmitted to the ground and any magnetic or metallic targets are energized by it. This current is abruptly cut off with the result that a very high voltage pulse is created. Targets which have been excited by the pulse of current continue to radiate the induced signal at a an ever decreasing signal strength which decays exponentially (drops off quickly and then persists at a lower rate of decay for some time longer. Each target has its own curve - called its time constant.
Low conductors of all sizes decay very quickly and high conductors and ferrous targets persist longer - have a longer time constant.
In all metal there is only an early sample taken of the target signal and so the decay is less - all targets give their full short pulse delay signals and all sound a high tone.
When either of the multitone or mute modes are selected, an addditional sample of the delay curve of the target signal are also taken at a later point in time and therefore further down the delay curve where the signal strength is ugh weaker than it was in the first sample. A comparison and analysis of the two samples result in longer persisting targets being either assigned a low tone (multitone) or are muted (mute mode).
The action of this analysis of the second sample is on the later and therefore relatively weaker signal. It involves amplifying the second sample so that the analysis can take place. This results in an increase of noise and the slight reduction of sensitivity to longer persisting targets.
In this process the depth of detection of all targets is somewhat less than in all metal which operates on only the earlier stronger signals. The lower conductors, with their fast decaying signals are less effected however than higher conductors or ferrous targets with their longer persisting signals.
Alexandre has posted elsewhere that the effect is that the loss in discriminate modes for all gold jewelry below 22kt (regardless of weight) is minimal perhaps 10% less depth than the same target in all metal. So a thin gold ring detected at 12” in AM might be detected at 10.8” in discriminate. As the conductivity and therefor the target’s time constant increases however the difference is depth is larger - for 22k it might be 20%, for 24k depending on size they might return a low tone or be muted.
So, in practical terms, the iron ID function works to the full depth of detection, but that depth is somewhat less than in all metal - although jewelry below 22k is not severely affected.
But what about deep iron or that large 24kt Asian ring? If the system works as I have explained, if you can get a signal from it in multitone, it will ID correctly with a low tone. If you hear a deep iron target in all metal and you switch to multitone, it should either give a low tone in multitone or disappear due to the depth loss described above. Remember, long persisting targets seem to suffer more depth loss than low conductors with their fast signal decay
What about a 14k ring at the edge of detection depth in all metal? You may or may not get a signal in multitone or mute due to the 10% or so depth loss.
If all this was clear as mud - my apologies, but I have actually worked pretty hard to BEGIN to unserstand this stuff. Once I have a machine to play with for an extended period it will be easy enough to document actual tests of various targets at various depths.
so I sat down and wasted a few hours trying to explain what I THINK I know about the function of the AQ’s iron ID function. In spite of having had my hands on three different ones since October ‘18, I never got far enough along with any of them to really document actual controlled results in the ground. Anyway, if you want to ruin your afternoon or get a headache - press on....
As far as Tone ID at depth, first remember that in all metal, all targets return the same high tone. I will now try and explain the discrimination function and its results.
Now if the question is do the ID modes of multitone and mute provide the same depth of detection as the all metal mode, the answer is no. The depth difference has been progressively reduced as the development of the AQ went on.
The the depth penalty is due to the action of the discrimination system. the discrimination is achieved by analyzing the decay of targets return signals over time.
WARNING - I am not a physicist or an electronics engineer. The following is based on what I believe to be correct based on several years of studying PI detectors and the information Alexandre has shared on various forums and in private communications between him and I.
Pulse Induction detectors do their target analysis in the time domain - that’s why Whites called the TDI by that name. A strong current is created in the coil which creates a magnetic field. This is transmitted to the ground and any magnetic or metallic targets are energized by it. This current is abruptly cut off with the result that a very high voltage pulse is created. Targets which have been excited by the pulse of current continue to radiate the induced signal at a an ever decreasing signal strength which decays exponentially (drops off quickly and then persists at a lower rate of decay for some time longer. Each target has its own curve - called its time constant.
Low conductors of all sizes decay very quickly and high conductors and ferrous targets persist longer - have a longer time constant.
In all metal there is only an early sample taken of the target signal and so the decay is less - all targets give their full short pulse delay signals and all sound a high tone.
When either of the multitone or mute modes are selected, an addditional sample of the delay curve of the target signal are also taken at a later point in time and therefore further down the delay curve where the signal strength is ugh weaker than it was in the first sample. A comparison and analysis of the two samples result in longer persisting targets being either assigned a low tone (multitone) or are muted (mute mode).
The action of this analysis of the second sample is on the later and therefore relatively weaker signal. It involves amplifying the second sample so that the analysis can take place. This results in an increase of noise and the slight reduction of sensitivity to longer persisting targets.
In this process the depth of detection of all targets is somewhat less than in all metal which operates on only the earlier stronger signals. The lower conductors, with their fast decaying signals are less effected however than higher conductors or ferrous targets with their longer persisting signals.
Alexandre has posted elsewhere that the effect is that the loss in discriminate modes for all gold jewelry below 22kt (regardless of weight) is minimal perhaps 10% less depth than the same target in all metal. So a thin gold ring detected at 12” in AM might be detected at 10.8” in discriminate. As the conductivity and therefor the target’s time constant increases however the difference is depth is larger - for 22k it might be 20%, for 24k depending on size they might return a low tone or be muted.
So, in practical terms, the iron ID function works to the full depth of detection, but that depth is somewhat less than in all metal - although jewelry below 22k is not severely affected.
But what about deep iron or that large 24kt Asian ring? If the system works as I have explained, if you can get a signal from it in multitone, it will ID correctly with a low tone. If you hear a deep iron target in all metal and you switch to multitone, it should either give a low tone in multitone or disappear due to the depth loss described above. Remember, long persisting targets seem to suffer more depth loss than low conductors with their fast signal decay
What about a 14k ring at the edge of detection depth in all metal? You may or may not get a signal in multitone or mute due to the 10% or so depth loss.
If all this was clear as mud - my apologies, but I have actually worked pretty hard to BEGIN to unserstand this stuff. Once I have a machine to play with for an extended period it will be easy enough to document actual tests of various targets at various depths.
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