Impulse AQ - Digging With Tones & Disc In General

[Rick K - First Member]

Dave. In Tone or Mute mode, the reject control sets a “balance” point. This Is a point along a time line, All signals are analyzed by how quickly their signals decay. 

Signals which decay quickly fall on one side of the balance point, signals which persist longer fall on the other side. 

How long signals persist is based on a couple of factors. Chief among them are the conductivity of the target, the magnetic characteristics of the target due to ferrous content and the mass of the target.

In tone, the AQ gives a high tone to those targets on the “left” or short persisting side of the balance point. It gives a high tone to those longer persisting signals which fall on the “right” or long persisting side of the the balance point.

Signals which decay quickly and therefore are assigned a high tone include gold, aluminum, brass, lead - but only until their mass becomes so large that the signal persists beyond the balance point - in that case they fall “beyond” the balance point and would give a low tone.

A big piece of aluminum will give a long persisting signal, as will a piece of silver or a nail. In the first case, because of its mass, the second because of its conductivity and the third because is is a significant ferrous object.

This is totally different than the operation of a VLF detector which uses phase shift to do discrimination.

[palzynski]

2 hours ago, Steve Herschbach said:

All I can do is report real world results. I am not unhappy with the result and I am not going to try and be that aggressive trying to reject targets. I’d rather be more conservative than overly aggressive in that regard. I think you are discounting the effects of orientation in the ground being such that not everything signals as if it is laying flat on the surface. Not all targets give perfect textbook example signals when buried in the ground. The hair pins I dug dig not give a double blip due to their orientation and depth. I would expect no different from tabs. As far as the ratio, I was digging what I believe to be deeper, older targets. Only one nickel is a clean, recent drop. VLF operators have probably skimmed off the shallower, more recent items to some degree.

I would caution against reading too much into any one single report by any one person. It takes time and many reports from many people under a wide range of conditions for a fuller picture to develop.

Hi Steve , thx for your all infos ..

From your pic I have counted a total of 104 targets including ( 24 ferrous + 10 bottle caps) .

So you only digged around 30% iron targets of the total. So this means 70% potential valuable targets ...I am not a beach specialist but this looks very interesting ...  Looks like the AQ eliminates quite a lot of iron trash...

Of course with a VLF there would have been close to 0% iron targets , but the VLF does not go as deep as the AQ ...

[Steve Herschbach]

On 6/25/2020 at 4:50 AM, midalake said:

Hi Steve

How is it even possible to reject silver [giving a low tone]  and still detect gold [with high tone]?  With tones modes?  

If you don't know maybe someone else?  Seems impossible. 

Thanks Dave

I practically wrote the book on discrimination with ground balancing PI Dave, and have discussed it for years starting with the Garrett Infinium, then Minelab’s and the TDI. The AQ is just the latest and I already wrote it up also. I included references to the past threads on the other machines. There is lots of information in prior threads on this forum about it. Honestly, I have been going out of my way to try and educate people on this for the last year, so I’m kind of surprised you have not seen it. I knew this would confuse people so have been trying to alleviate that confusion well in advance of the machine appearing. I will start including the links in all my future threads.

Long story short the AQ performs very much as I have anticipated all along, no real surprises, and no disappointments at all outside of the battery system.

Fisher Impulse AQ Discrimination Explanation 

More here

 

 

[Steve Herschbach]

Better yet, I am going to create a new pinned topic at the top of this forum that references critical prior threads on the AQ for easy future reference. 

[midalake]

26 minutes ago, Steve Herschbach said:

I have written extensively in the subject Dave, and link to the information in many prior threads. You are thinking VLF and conductivity. Stop it.  Think PI and time constants.

Fisher Impulse AQ Discrimination Explanation 

 

Well let take it to the next step, where the machine assay's the target and then it just magically jumps in your pouch!  ?

[Steve Herschbach]

I made my post less snarky and added another link. You have motivated me Dave to create a better way for people to find critical past threads on issues relating to the AQ - thanks!

[midalake]

2 minutes ago, Steve Herschbach said:

I made my post less snarky and added another link. You have motivated me Dave to create a better way for people to find critical past threads on issues relating to the AQ - thanks!

Well I have really not read on the topic, because I was using the Sovereign which is very PI like in it's all metal mode.[and still use]  Years ago I ran a CZ-21 for a while but could not bring it up to speed where I hunt. Also the only other machine I considered for my beach use was the Dual Field. However I am not a fan of 12" or bigger coils for my style of beach hunting and conditions, also hunting in another country I did not like the fact it used batteries.

  I am an old dog that can learn new tricks.  I have no fear what so ever the AQ will talk a language that I understand.  The question might be trade-offs.    

[cjc]

On 6/24/2020 at 8:57 PM, Steve Herschbach said:

There is a lot of audio to work with.

That's well said, Steve and herein lies the power of this machine--in conjunction with the reject.  I also think that this detector has good, clean optimization--and with practice--this will work well with the amount of audio detail.   Those narrow clean high tones are "the money."

cjc

[Steve Herschbach]

Yeah, I really liked the audio, and the audio options on the Impulse, and took to it immediately. I am satisfied with both the depth and the discrimination capability. The machine worked perfectly in fresh water, although there are reports that salt water use has been more problematic. I wish there was more transparency there, but people do not seem to want to go public, perhaps because the issue was belittled when it was mentioned a couple times? Whatever, but something is up with saltwater stability, but I've got no idea what the exact issue is, nor how widespread.

I hated to let the machine go, but am hoping a more polished version will appear someday in regular retail channels. I'm picky about some stuff, and the kludge that is the current battery system proved more a turn off for me than I thought it would be. I'd have kept it if not for that. I'd also have to hear more positive reporting from saltwater users also, before I'd consider the AQ again, so my eyeball is more on the gold prospecting version now.