Impulse AQ In Surf / 36 Psu Salinity

[Tony]

I have never owned the Impulse AQ but I’m curious to know if some of these moving salt/mineral issues are solved by running longer pulse delays. Pulse users are not “detuning” their machines by running at 20uS in these sorts of conditions. I have recently acquired a mint (and fully upgraded) Garrett XL500 pulse which has a minimum pulse delay of 20uS. In churning white salt water, I get just a very slight salt signal only but still hear small gold at good depth……this is the perfect balance in my opinion. I’m not a Fisher engineer but I just never could understand how this detector (Impulse AQ) could quietly operate at quick delays in these conditions…….it goes against the very principles of pulse induction.

Tony

[Tony]

2 minutes ago, Tony said:

I have never owned the Impulse AQ but I’m curious to know if some of these moving salt/mineral issues are solved by running longer pulse delays. Pulse users are not “detuning” their machines by running at 20uS in these sorts of conditions. I have recently acquired a mint (and fully upgraded) Garrett XL500 pulse which has a minimum pulse delay of 20uS. In churning white salt water, I get just a very slight salt signal only but still hear small gold at good depth……this is the perfect balance in my opinion. I’m not a Fisher engineer but I just never could understand how this detector could quietly operate at quick delays in these conditions…….it goes against the very principles of pulse induction.

Tony

Okay…..just read some other posts and it appears that running higher delays is not a solution. Safe to say that the best pulse machines are no longer made 😩

[cudamark]

The delay range on the AQ is from 7 to 11.5 according to it's control, but, I understand that the range is actually a bit wider than that in reality. Turning it to the longest delay helps some, but, not enough for most conditions here in SoCal. I didn't expect the AQ to have perfect discrimination, but, being a PI water machine, I did expect it to be stable in moving salt water. I definitely didn't get either one....

[Carolina]

I guess I can count myself lucky. Here in Va. Beach Atlantic Ocean, both of my AQ’s run smooth on all but 1/2 block out of 80+. I do have a lot of chatter off one certain hotel so I assume under ground power or strong WiFi. In what I call the wash ( knee deep and shallower ) or just above the rim my machines run well with mostly smooth threshold. I have dug a multitude of gold as deep as 17” at best guess. In the lower Chesapeake Bay, opposite from Beechnut, I can work fully submerged to chest deep or thigh deep and shallower. If the control box is fully submerged or completely out of water there is no issue for me. If a rouge wave splashes the control box, the detector will sound off. Eric had one of my machines for four months and did exhaustive research and one thing he found, was the locknut on  the female connector is metal not plastic. It develops capacitance and creates the machine gun effect and false signals when the waves hit it. He made me some plastic nuts that greatly reduced that problem but did not eliminate it completely. I work with the tide though and keep the box mostly submerged and a few hours completely out of the water. I did have an issue with a sealing washer missing on my threshold pot and Fisher promptly replaced it. I know that Alexandre has plans for a different coaxial pin that will not break the shield as is done with the limited pin which he thinks will cure the capacitance issue. I can tell you I have first hand knowledge that Carl Moreland and Fisher engineers have little to do with the AQ. It is Alexandre’s baby and he appears to be the sole engineer for this project. I bought my AQ limited with the idea it was to give my 2 cents worth to  First Texas on my thoughts of its pros and cons and what could be done to better it. Like I said at first I must be lucky as I would not part with either machine. The tone mode allows me to skip nearly all the coins on my beach and concentrate on gold only. A 18k pig with a large silver content can give an iron grunt, but knowing my beach and realizing that ring most likely will be deep in the wash rather than mid or high beach, I know when to dig the grunt. I wish everyone had the same experience that I have with mine and maybe Alexandre will turn one out soon. Good luck everybody and Merry Christmas!!!

 

 

[cjc]

On 12/10/2021 at 6:05 AM, Steve Herschbach said:

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 experienceonsti 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.

 Glad to see that Im not the only dog barking at the carriage.   What's disturbing is the elegant array of denials--some unwitting--others not.  Im kind of reminded of a concept in Group Dynamics--that of the "Abilene Paradigm. "  With this--a group of people feel compelled to travel to Abilene for ice cream. But when the get there they  realize that no one really wanted to go--problem being a lack of communication.  Maybe a better metaphor would be that of a train that has travelled for quite a long distance at speed--but no one paused to check if the wheels were actually touching the ground.  In this case the ground would be the simple basics of detector operation--ease of use and stability.   Without them we're well beyond the "ugly baby" simile and into the realm of  "le infante terrible."  The term that comes to mind is "ass in the breeze" interference -wise.  I get the sense that Alexandre was not able to replicate a broad enough spectrum (and  ranges) of interference sources (mineral / salt, EMI) to produce a machine with a range of adjustment to allow for stability under a wider range of conditions.  Although his efforts to look at salinity, sweep variation, tuning and other factors were valiant--the product lacked versatility. Ive never had a detector that I didn't quite know what to do with.  this is that machine--squelching on my freshwater dream find--big 22k, and temperamental in salt.  Im testing on a hotel strip beach and from the looks of it the amount of electricity in the ground precludes the use of this machine--after almost 3 weeks of fiddling.  I've just finished taking it back to the one area of sidewall where I was able to take out a dozen or so deep coins--only to find that now--something had changed--even at 11.5 uSc--basically haywire--with severe sweep  / response latency issues----OR stable at the lower delay ranges--but with no target response.  Frustrating  and bewildering.  Noise when the coil jack is touched, noise when the coil itself is touched--"ass in the breeze"--no match whatsoever for a rough salt environment.  The only suggestion I can offer is  that FT need to quit this tap dance of excuses and recommended "tweaks" and send one of  this detector to the master-- Eric Foster--free.  Something along the lines of the Aquastar's coil ground pin might bring this machine successfully to market--where it deserves to be.  Eric has also  suggested to me that problems with the distribution of power throughout the charge cycle might be at fault.

Tantalizing is exactly the word. 

Im very grateful to you Steve for your reply,  deft "voice of reason" analysis, and reporting on this machine. 

cjc

[Tony]

I just feel that whilst developing the AQ, they should have kept one eye on the basics of some of the high performing PI detectors of the past……proven design, engineering and performance. If it ain’t broke……well you know the rest. 

 

[Steve Herschbach]

2 hours ago, Carolina said:

In the lower Chesapeake Bay, opposite from Beechnut, I can work fully submerged to chest deep or thigh deep and shallower.

Chesapeake Bay is a lower salinity environment.

https://www.chesapeakebay.net/discover/ecosystem/physical_characteristics

“In general, the lower Chesapeake Bay is salty and the upper Bay is fresh. Salinity gradually decreases as you move north, farther away from the ocean, and increases as you move south.

Salinity is highest at the mouth of the Bay—averaging 25 to 30 ppt—where water from the Atlantic Ocean enters. The head of the Bay and its tidal rivers are fresh, with a salinity of less than 0.5 ppt.

The middle portion of the Bay and its tidal rivers are brackish: a mixture of salt and fresh water. Brackish water has a salinity of greater than 0.5 ppt but less than 25 ppt. Most of the water in the Bay is brackish.”

[Carolina]

12 hours ago, Steve Herschbach said:

Chesapeake Bay is a lower salinity environment.

https://www.chesapeakebay.net/discover/ecosystem/physical_characteristics

“In general, the lower Chesapeake Bay is salty and the upper Bay is fresh. Salinity gradually decreases as you move north, farther away from the ocean, and increases as you move south.

Salinity is highest at the mouth of the Bay—averaging 25 to 30 ppt—where water from the Atlantic Ocean enters. The head of the Bay and its tidal rivers are fresh, with a salinity of less than 0.5 ppt.

The middle portion of the Bay and its tidal rivers are brackish: a mixture of salt and fresh water. Brackish water has a salinity of greater than 0.5 ppt but less than 25 ppt. Most of the water in the Bay is brackish.”

As I stated, I hunt the lower Chesapeake and the Atlantic. Lower being the mouth of the bay. 

[Steve Herschbach]

6 minutes ago, Carolina said:

As I stated, I hunt the lower Chesapeake and the Atlantic. Lower being the mouth of the bay. 

I’m not trying to argue with you or dispute the machine works for you. I’m attempting to explain possible reasons why detectors in higher temperature/higher salinity areas than what you are likely working in are having these issues. The machine worked fine for me also but it clearly is not working for other people. It’s great it worked for me, for you, but what about them?

Or it could simply be half these machines are outright defective, and it’s just a coincidence where they are located.

[Chase Goldman]

1 hour ago, Steve Herschbach said:

I’m not trying to argue with you or dispute the machine works for you. I’m attempting to explain possible reasons why detectors in higher temperature/higher salinity areas than what you are likely working in are having these issues. The machine worked fine for me also but it clearly is not working for other people. It’s great it worked for me, for you, but what about them?

Or it could simply be half these machines are outright defective, and it’s just a coincidence where they are located.

Steve/Carolina - Jumping in here as I think you might both be talking past each other a little bit (or not). 

The 80+ blocks of VA Beach that Carolina referred to (and along which he had little issue) are adjacent to open ocean (the Atlantic).  You wrap around the VA beach peninsula to the north and you are technically at the 18 mile wide mouth of the Cheasapeake (east of the Cheasapeake Bay Bridge-Tunnel), but really, it's the Atlantic Ocean and the corresponding ocean level salinity of about 34 ppm.  Carolina calling it lower/mouth of the Cheasapeake Bay, while true geographically speaking, really IS Atlantic level salinity on the VA Beach hotel waterfront (i.e., well above the 30 ppm upper end of the lower/mouth of the Cheasapeake salinity range published), which was his point in the last post.

In other words, as Carolina states, he must have gotten lucky with his two AQ's, because given the more typical ocean going salinity levels he is hunting in, his experience with the machine has been more positive than most using it in a similar environment.

All that being said, Steve I think your conclusion that the AQ quality/design (?) variations from machine to machine appear to be significant. The result of all the potential sources of noise (connectors, conductors, coils, pots) that can readily introduce stray capacitance, inductance, and ground loops that can easily disrupt the resonsnt balance points of sensitive analog circuitry just make things worse.  In other words, as I think Clive said earlier, the AQ circuitry appears to not be set up to deal with a wide variability in environmental conditions and the build quality issues that can introduce variable circuit behaviors just seems to exacerbate the issue.

The radio silence on further AQ development is not surprising.  The analog-based design may be doomed with respect to the ambition of being able to be more widely applied to a range of conditions vs. a more specific, narrow use case (e.g.  wet beach to ankle deep).  That is not good news for a machine that is basically a niche machine to begin with.

But what do I know?  I cancelled my AQ order early on once I realized it really didn't intersect with my minimal in-the-water beach hunting experience and have never had one in my hands.