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Steve Herschbach

Where Will The Holes Be In The Fisher Impulse System?

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Anyone who has used a White’s TDI much knows that the ground balance can be manipulated to exclude certain targets. This is less about conductivity as White’s sells it, but about target size. What that means is you can exclude high conductors and large ferrous and concentrate on smaller low conductors and small ferrous. Or you can exclude small ferrous and small non-ferrous and go for higher conductors and larger ferrous.

The system does not make gold hunters happy because to dig small gold you still dig small ferrous stuff. Or when you are digging larger gold you still dig nails.

My guess on the Impulse is that it is using at least two “ground balance” points to bracket the most common ring responses, which tend to be lower mid-range targets. It would be quite a balancing act tuning out both the smallest stuff and the largest stuff and just hit the sweet spot. I personally think this could be a powerful method for essentially cherry picking rings while eliminating most small ferrous and large ferrous. There still will be a class of mid-range ferrous targets that read good - I promise the system can’t be perfect.

The flip side however is that at least two large “holes” are going to have to exist as a result. One that misses smaller gold targets, like earrings and chains, and possibly the smaller thin rings. And then on the top end very large heavy men’s rings and silver rings, and most coins may also be lost.

The solution will be to turn off the discrimination and go back to digging everything. Hopefully there will be some ability to tweak the discrimination as target / trash mixes do vary somewhat and shifting the accepted range up or down would be beneficial.

I am just guessing based on what I know about how a PI works and how one could potentially discriminate out a class of targets. I could see a very acceptable trade being made, more depth at the expense of certain target classes.

Yet I wonder how the general public will react to videos displaying numerous gold items, especially large ones, being completely undetectable by the Impulse in discrimination mode? The wiser among us may understand what’s going on and the trades being made, but if I know one thing about a lot of folks, the idea the machine misses good stuff won’t fly too well. Witness the silver dollar on edge fiasco with the Equinox, or the similar issue with the early Gold Bug models.

Anyway, don’t take this as being more than speculation, but it is something that the more knowledgeable among us will want to find out quickly once the Impulse hits the streets. It should be easy to find out, just air test with a large range of jewelry targets running from tiny to large and check the results. And the same with ferrous. Unless a Pulse Devil miracle machine is in the works, and I am betting that’s not the case, there will be some definite caveats to deal with when employing the discrimination system.

For me it’s kind of a non-issue. I’d be happy with the machine as a straight up pulse digging everything. It’s the ergonomics and price along with the finely tuned low pulse delay that have me looking more than some magic discrimination system. Anything it does there will be just a bonus. I will actually be surprised if the nugget hunting terra version has any discrimination at all due to the possible issues I am outlining. It would tune out most natural gold nuggets. Optional blocking of high end nail type signals would be of more benefit to nugget hunters in small gold areas. It would risk missing large nuggets but in some places that’s not much of a worry.

Fisher Impulse AQ Data & Specifications

fisher-impulse-aq-pulse-induction-metal-detector-beach-gold-rings-waterproof.jpg
Fisher Impulse AQ pulse induction metal detector

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Completely agree with everything you have mentioned Steve.
Manufacturers mustn’t get too cute with a PI.......let them be raw and powerful as they were designed to be. I will never detect having the knowledge that I am walking over a nice fat gold ring and that is why I run my TDIBH with GB Off........no “holes” and better depth. The beach version of the AQ should be a straight PI...... and it would be cheaper to buy. Don’t let the AQ try to be all things to everyone. If Fisher plan to develop other versions then the case for a simple, powerful, straight PI for the beach is even stronger. White’s did a very good job on the TDIBH......Fisher could learn from them.

Tony

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The latest posts by LE.JAG have indicated that the “hole” at the upper end has been steadily nibbled away at - and now lies “above” even massive rings and 22kt gold. 24k is likely still “in the hole” - which is to say, excluded along with ferrous targets, silver and other high conductors when the discrimination function is enabled. 

 

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Steve,

Some very good points here.  For me the problem with the Impulse is that for some bizarre reason First Texas has chosen to remain almost completely quiet on the machine.  The questions of "holes" in gold targets are very legitimate and it is surprising to me that Fisher hasn't taken the time to at least release some sort an update on this detector. I mean, they've selectively teased everyone with short videos and drops of prototypes at shows, so why not just tell those of us honestly what's going on? 

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It’s mainly me who has teased everyone by posting stuff about this since June 2018. Fisher showed a prototype at one show in Germany this last winter.

It’s a totally new thing for them. The entire design team was the subject of an “acquihire” of Alexandre Tartar and his fellow “Manta” team members.

It is by all accounts a more complex and tighter tolerance device that First Texas is used to producing. That and the likelihood that a dedicated beach PI will be a “niche” machine and therefore not a mass market seller, and the likely high production cost - make it understandable why they are proceeding very carefully.

 

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53 minutes ago, Rick Kempf said:

It’s mainly me who has teased everyone by posting stuff about this since June 2018.

https://www.detectorprospector.com/tags/fisher impulse/

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Don’t worry Rick, your reputation as unofficial spokesman for First Texas is quite secure. You do more to promote their detectors than anyone that actually works there.

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That all sounds excellent, especially the small gold results. I am in total agreement that any discrimination system has trade offs, even in the best VLF detectors. Those trades are perfectly acceptable as long as we know what they are so we can apply proper judgement on where to employ discrimination and where to dig everything. The big downfall for PI has always been its affinity for ferrous targets making it simply impractical for use in some locations. Impulse AQ addresses that issue and I expect the best places to use one initially will be exactly those locations that PI users have avoided until now.

I personally have no doubt this detector will be very productive in the right locations and look forward to using one myself. I have not owned a waterproof PI since I sold my ATX and have been waiting patiently for something better to come along. For me the waterproof TDI was too little too late. I wanted one from the very first day I used a TDI but after years of being ignored in my lobby efforts I found by the time White’s finally made one better things like the Impulse were on the horizon.

Very kind of you to post that information LE.JAG.....  thank you! It’s especially good to hear the Terra version is in beta testing, that bodes well for a dual machine introduction.

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