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Fisher Impulse AQ Discrimination Explanation

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13 minutes ago, ALEXANDRE TARTAR said:

The IMPULSE AQ cannot however be used to search for gold nuggets, other models are provided for this, they are more sensitive and do not need to compensate for the conductivity of seawater.

Thank you for the detailed explanation Alexandre. One question about the above statement - is the salt compensation still active in the all metal mode?

I hope you are feeling better soon!

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On 12/26/2019 at 1:02 PM, ALEXANDRE TARTAR said:

The IMPULSE AQ has a purely analogue analysis.

If this is the case then the Chinese copiers will be licking their chops waiting to reverse engineer this.  The potting compound had better be J&B weld with some phony decoy circuitry thrown in for good measure.

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I'm not worried about this, there are a multitude of details that make it difficult to copy.

Physics of materials ... I cannot say much more about this.
The gold versions are more interesting for copying, the market is more interesting.

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The gold and relic versions will be what interest me the most, since I use my TDI almost exclusively for gold jewelry hunting and one week a year to the beach.

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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 ....




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Welcome to the forum Alain. This is just my personal opinion, but comparing the Impulse discrimination to VLF detector discrimination is an apples to oranges comparison. To be fair the Impulse should be compared to other pulse induction beach detectors, where it is almost certain to offer a clear advantage. Anyone expecting it to offer discrimination as good as the best VLF detectors may very well be disappointed. My advice if that is a concern is to wait and see. As a longtime PI user the choice in this particular application is very clear for me, but for people like you more caution is advised. It is unlikely the AQ model is what you are looking for, and a coin/relic version of the Impulse is still just a distant rumor, nothing more.

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