Impulse AQ In Surf / 36 Psu Salinity

[cjc]

On 9/1/2020 at 9:31 AM, deborah195412 said:

The video's did not help my situation at all. I'm out in the water up to my neck.  In all metal mode, max pulse delay, ats 9-10, Sensitivity 3 -  When I sweep the coil there is no way I could recognize a signal unless it was shallow. I'm used to a little chatter and having a signal break through the chatter, but the audio in all metal, when sweeping the coil, is changing so much there is no way I could recognize a weak to medium signal. Just the fact that I have to reduce my sensitivity so low in conjunction with an ATS setting of 9 or 10, I'm losing all the advantages of the Impulse AQ. I still have hope that a smaller coil will help with this problem. until I can lay my hands on the 8 inch coil, I will continue using the machine in the volcanic sand mode where I can achieve a little stability. I will be doing some target testing on gold and platinum rings and other common targets to see what kind of depth to expect in that mode.

My machine is not the only machine acting this way. There is another machine here in Pensacola acting this way and 2 machines in Hawaii that are having problems. I am not sure if the problem is salinity or something else, but I have no problems with using my Whites Dual Field or my Eric Foster Goldquest Aquasearch V2 here in Pensacola. 

This is exactly the problem I continue to have and am working with the settings and asking around looking for a remedy.  Even at the highest Delay and SAT speeds there's more noise than signal in salt with any current.   I do have a small coil and have to say that although this machine is close to a workable stability level--I haven't found one yet.  the videos are encouraging and I'm grateful for the time Alexandre has put in to making them--but at the same time--in my own experience--flat out--this machine is hard to tune.  My worst fear was that it would be another TDI Pro--once de-tuned any advantage would be gone...certainly looking that way.  I just hope that FT doesn't engage in the familiar "NOX rarely leaks" type behavior that we've all come to know and love...  Shaping up as a great wet sander though. Call em as I see em.  Guess that's why I never got a production model proto as had been promised at one point. 

clive

[Steve Herschbach]

6 hours ago, cjc said:

This is exactly the problem I continue to have and am working with the settings and asking around looking for a remedy.  Even at the highest Delay and SAT speeds there's more noise than signal in salt with any current.   I do have a small coil and have to say that although this machine is close to a workable stability level--I haven't found one yet.  the videos are encouraging and I'm grateful for the time Alexandre has put in to making them--but at the same time--in my own experience--flat out--this machine is hard to tune.  My worst fear was that it would be another TDI Pro--once de-tuned any advantage would be gone...certainly looking that way.  I just hope that FT doesn't engage in the familiar "NOX rarely leaks" type behavior that we've all come to know and love...  Shaping up as a great wet sander though. Call em as I see em.  Guess that's why I never got a production model proto as had been promised at one point. 

clive

Yes, this problem is real, and all mentions of it were answered with excuses, or minimization of the problem. I never experienced the problem personally as I only hunted fresh water, and can vouch for the AQ performing well there at least. The problem appears to be related to high salinity situations, compounded by high mineralization - the exact reasons why you would normally want a PI. As far as I know the machine basically does not work in Hawaii, and apparently some other locations, unless detuned to the point that you may as well use a VLF.

[cudamark]

My experience as well. It's just way too noisy in our surf regardless of settings.

[cjc]

6 hours ago, cudamark said:

My experience as well. It's just way too noisy in our surf regardless of settings.

To be fair--this is a very deep, sophisticated pulse detector that tells ferrous from non-ferrous--huge deal.  You can also bring the coil into the edge surge.  But whole machine submerged?  I haven't learned the secret yet, anyhow.  Still testing and tomorrow will run Eric Fosters small coil but There seems  to be a an integral shielding problem.  Also once submerged--there's noise as the water runs off.  I know for sure Eric Foster could sort this out but FT is too proud to ask.  Im also told that said circuit came from a post by Eric on Geotech--purloined. 

cjc

 

[okara gold]

Mine is used 90% in the salt water. I am in SW Florida with mainly white to light brown sand. The big coil is noisy even with minimal swells and every time a swell comes in, it emits a long, loud howl sound. I do hunt with a delay around 9.5 -10.5 and an ATS around the mid-way point so this is expected.  When a swell comes in, sometimes I will stop the coil movement as it starts to "howl / drift" and it quiets down enough that I can continue the sweep. It is quieter coming from the deep water to the shore. When doing this perpendicular approach I can set the delay as low as 9 (sometimes). It is very hard to keep quiet when walking parallel to the shore and swinging from the shallow water to the deeper without it drifting severely. Every time the coil is raised off the bottom it reacts with the loud howl.

It was mentioned a long time ago that to help in discrimination in all metal you can gradually raise the coil as you sweep side to side over the target and if the signal quickly fades it is probably iron. This procedure for me is impossible to do in the salt water due to the severe drift noise. As soon as the coil is raised it howls! On shore it works as it should.

I can hunt roughly waist deep to the shallows without too much drift occurring. And this is ONLY if the water is fairly calm with minimal swells. I agree with Steve, that if you have to set the delay and ATS so high as to quiet the machine down you may as well use a VLF. If you strictly use the AQ out of the water, I find it enjoyable and deep if the area isn't too trashy.

I have the 8 inch coil that is much quieter in the water but am reluctant to use it much because of its small coverage.

[cjc]

1 hour ago, okara gold said:

Mine is used 90% in the salt water. I am in SW Florida with mainly white to light brown sand. The big coil is noisy even with minimal swells and every time a swell comes in, it emits a long, loud howl sound. I do hunt with a delay around 9.5 -10.5 and an ATS around the mid-way point so this is expected.  When a swell comes in, sometimes I will stop the coil movement as it starts to "howl / drift" and it quiets down enough that I can continue the sweep. It is quieter coming from the deep water to the shore. Whe.  Othern doing this perpendicular approach I can set the delay as low as 9 (sometimes). It is very hard to keep quiet when walking parallel to the shore and swinging from the shallow water to the deeper without it drifting severely. Every time the coil is raised off the bottom it reacts with the loud howl.

It was mentioned a long time ago that to help in discrimination in all metal you can gradually raise the coil as you sweep side to side over the target and if the signal quickly fades it is probably iron. This procedure for me is impossible to do in the salt water due to the severe drift noise. As soon as the coil is raised it howls! On shore it works as it should.

I can hunt roughly waist deep to the shallows without too much drift occurring. And this is ONLY if the water is fairly calm with minimal swells. I agree with Steve, that if you have to set the delay and ATS so high as to quiet the machine down you may as well use a VLF. If you strictly use the AQ out of the water, I find it overall enjoyable and deep if the area isn't too trashy.

I have the 8 inch coil that is much quieter in the water but am reluctant to use it much because of its small coverage.

Thanks for your run down Okara. Defiantly an East / West machine--that downhill drag wrecks it.   Certainly great on shore and Im in the process of testing a small coil but the overall shielding issue is still there.  These tradeoffs are part of detecting but there has to be limits to how degraded the performance is under typical conditions.   A simple machine like the Cuda has none of these problems. 

cjc

[cjc]

On 12/8/2021 at 8:24 AM, Steve Herschbach said:

Yes, this problem is real, and all mentions of it were answered with excuses, or minimization of the problem. I never experienced the problem personally as I only hunted fresh water, and can vouch for the AQ performing well there at least. The problem appears to be related to high salinity situations, compounded by high mineralization - the exact reasons why you would normally want a PI. As far as I know the machine basically does not work in Hawaii, and apparently some other locations, unless detuned to the point that you may as well use a VLF.

No-one is a bigger fan of this detector than me.  But I\'ve spend more time fiddling with it than hunting on this my second salt water trip.  The first week with it I was unable to hunt at all with this detector.   As a keen "student" of pulse machines I thought for sure that there would be a simple cause to be found:  a non-linear ATS / Delay solution, electricity in the ground from hotels on shore--as stated "combination of salt and mineral'...Sensitivity or Delay too high....overall frequency...my methods are exhaustive and broad -based.  I've even considered solar flares as a possible source of interference.  Still looking, still waiting for my "secret weapon" to work.

cjc

[Steve Herschbach]

On 12/9/2021 at 8:25 PM, cjc said:

No-one is a bigger fan of this detector than me.

I’d argue with you over that one. I followed this machine from before day one, gleaned every clue about it, and posted here for years about it in anticipation. Lined up one of the first, and gave some pretty glowing reviews, that in some ways I now regret. My use in fresh water only gave an incomplete view of the machine. And frankly, those having salt issues were all strangely reticent about saying so publicly, making me question how real those issues were. It’s like nobody wanted to come right out in public and say the baby was ugly. deborah195412 was the only person to go public with this early on, and was explained away as having a bad unit. I’d heard private comments, but was loath to make much of second hand information.

Salinity seems to be the key, though it also could simply be a problem with individual units. Joe Beechnut has had perhaps the greatest success with this detector in water. Yet he hunts exclusively in lower salinity brackish estuary waters. He is also in cooler water. Higher temps, high salinity, seems to be a common factor, mineral less so. I speculated on heat buildup in a epoxy sealed high voltage circuit maybe being an issue with circuit drift, but was told that was not it. I still also question that however. So salt, high temps…… something is up, and perhaps is the reason why First Texas has gone silent on this machine. Well, except for a couple video mentions, and Kellyco hyping it up as available soon.

The AQ is tantalizingly close to being the perfect water PI. For me performance was great, although the preset ground balance was an issue in my extreme soil. It was always reactive to the soil, but the autotune made it useable. My main issue was dissatisfaction with the unfinished mechanical aspects. i.e. klunky battery pack and cable setup. I also think the mechanical knobs will be a service issue long term, sealed touchpad would be more reliable.

But this inability to perform in places like Hawaii is a complete product killer unless solved. Hawaii was for me the entire reason for coming to love ground balancing PI performance, able to handle both salt water and basalt hot rocks at the same time. If I had made a trip to Hawaii with mine, and it had not worked, I’d have been livid, and far less forgiving than you Clive. This thing was supposedly vetted. Here is what Tom Walsh, President of First Texas wrote in his “Disclosure” which each buyer was asked to read and confirm their acceptance of:

“Fisher is offering the Impulse®-AQ Limited to a select group of experienced early adopters who want to experience design and technological innovation in real-time, as it unfolds. The Impulse®-AQ Limited is not a prototype or pre-production metal detector; it is the first edition to a new product line of Impulse® technology.” 

I’d say at this point the Impulse AQ as sold to us was and is clearly a prototype/preproduction model, and everyone involved was charged good money to do what is normally expected of paid prototype testers. That may not have been the intent, and Tom Walsh was probably just believing what he was told, but this detector was not properly vetted and completed before sale. That’s not an accusation. It’s simply a fact.

[abenson]

Man am I glad I passed on the Impluse when my name came up. From the sound of it there's no way it would have worked at the Great Salt Lake especially in the water. Combine that with some of the rock outcroppings which appear to be volcanic in nature and even cause threshold drift on my GPX, the Impulse would have been totally useless. Early reviews were a warning sign to me that FT didn't have everything figured out yet. The problem FT has now is that even when they do release a completed Impluse, everyone will be skeptical of it's performance. A better option would have been for them to give 20 or 30 to people in the field and kept quiet about the issues it had until the problems were worked out. 

[cudamark]

I got one of the first handful of AQ's, so, I was an early tester of this detector too. I had the same problems that Deborah had as I mentioned early on in this thread. I followed all the suggestions that those who were having some success with theirs gave, but, nothing has helped in the surf. In damp sand, it doesn't work too bad, except for the continuing fact that it's discriminating abilities are pitiful and totally unreliable. In sopping wet sand, it's still a chore getting it stable enough to get deep targets except for big iron. As mentioned many times, by the time you detune it enough to make it stable, you may as well just use a VLF machine and enjoy life.