More Fun with the Impact 7" Concentric Search Coil

[Sven]

Went back to a school yard that I stopped at briefly a few weeks ago.
I got lucky and just happened to hit on area that started producing right away. It's always a great thing when the first or second signal you dig up is a Toonie ($2 coin).
Within about 15 minutes, dug up 3 Loonies. That's $5, on a roll now. Then a couple more. After an hour, that makes for a good haul. Did find a bunch of pennies in that time and a lot
of those neat pulltabs who want to be rings. Couldn't figure out why I wasn't finding any other change, dimes, nickels, quarters. Further away from the $1 and $2 coin area, started to find some dimes, then quarters and just one nickel.
A couple more Loonies there as well. For about 2.5 hours, scooped up approx. $14 in change.

There was some EMI in the area, quickly dispensed with by switching the frequency shift a couple numbers. Hunted mostly in Di3 mode, Gain at 95. 14Khz.

The new 7" concentric would make a great addition to any Impact owners coil collection.

 

[Tom Slick]

I'd love to get the 7" concentric for the Impact. Just can't find anyone that has one in stock.

 

[OregonGregg]

LOL Well Tom another advantage of the Racer 2, you can get the new coils for it......but be patient Big K might have them in 6 months. It did take them approx a year to get the 5.5 x 10 Concentric for the Relic machine. After all, they are the North American Distributor for Nokta and these things take time

 

[Tom Slick]

Gregg - I'll probably just sell the Impact because I can't get a concentric coil for it.

 

[dfmike]

Sven, can you distinguish the copper pennies from the other Canadian clad with the Impact ? I'm just asking that because you seem to be digging the pennies with the other high conductors. I find that on the CoRe, if I want to find loonies, I have to dig the pennies as well. The ID of both is 82 most of the time. About a third of the pennies ID at 85 and I have no idea why.

Your ratio of quarters to dimes is the opposite of what I get. In fact, I find about 8-10 dimes for a quarter. I'm still learning the Nokta's lingo so that might change somewhat.

Do you find it easier to get the steel core clad with the concentric ? You seem to be doing very well with it in any case. "Doing very well" is an understatement !

 

[Sven]

Sven, can you distinguish the copper pennies from the other Canadian clad with the Impact ? I'm just asking that because you seem to be digging the pennies with the other high conductors. I find that on the CoRe, if I want to find loonies, I have to dig the pennies as well. The ID of both is 82 most of the time. About a third of the pennies ID at 85 and I have no idea why.

Your ratio of quarters to dimes is the opposite of what I get. In fact, I find about 8-10 dimes for a quarter. I'm still learning the Nokta's lingo so that might change somewhat.

Do you find it easier to get the steel core clad with the concentric ? You seem to be doing very well with it in any case. "Doing very well" is an understatement !

The copper pennies can come in about 78-82-85, getting a feel now what is a penny and what is not, they seem to come up about the same numbers all the time. On the concentric coil, they do sound a bit different than clad, can't describe it yet. Every time I get the audio response and ID number, I think dang another penny. I do use the pinpoint toggle to get another indicator of the targets ID. Sort of what I used to do with Tesoros and then decide by the two responses and how well the target de-tunes each time the pinpoint toggle is pulled. Dimes can give a higher reading as high as 85 or so and some in the 50's, while pinpointing they give a raddy sound if near the depth capability of the Impact. quarters can fall around the 65 range and then sometimes in the 70's. Nickels around the middle 50's. Loonies around 69-72 or so depending upon the year. Toonies, think they come in around 72-79, I am usually suprised when I find them. I could cherry pick the Loons and Toons by digging 65-80's they do give off a particular response when pinpointing. The factory pre-set Di3 mode seems to be really ideal for Ca clad with the tone breaks as is. So I haven't messed with them yet. Down the road I plan on playing with the settings as I formulate ideas as my learning progress continues. Finding silver rings pop in high 80's to 90's. But small canslaw can fool you as they ring in around 83-84 even at 3-4" deep. Noticed maybe a good indicator that ID is canslaw and not a coin by the pinpoint audio response, if the audio is louder in PP mode than was in Di3 detection mode, a number of times today proved to be canslaw. Finding most coins will give a clear crisp narrow target audio signature. If I get a bouncy number and bouncy audio response, with a quick high tone and a flash of a high 60+ number, worth checking out. Could be a clad coin on edge. With any new detector I will dig a lot of trash and coins etc. to educate my brain to the responses. The more of these targets you dig in a short period of time, it starts to imprint the brain as to what the target might be. Right now trying to guess the target below the coil.

Now just a word about the DD coils, have been using the small and 5x9 ovals. Target signature is a bit different audio wise, clad will give off a blended med-high tone compared to most pennies. Loons and Toons give off the same blended tone but, detection footprint is different. When you pinpoint and use the pull the coil back off the target DD method, the target length will be from almost the tip of the coil to the rear. You could almost guarantee its a Loon or Toon if the ID number falls within range. Those two coins just pop right out at you. If you also use the PP toggle and detune they will detune to a small coin size audio response fairly quickly, while junk will remain huge.

With the concentric coil, you need to overlap each sweep to hopefully get everything in an area. The DD coil is a bit more forgiving in this regard, you can cover an area faster. The Impact does not miss much depending on how its set up for a given depth. I like both the concentric 7" coil and the 5x9" DD coil for general purpose hunting. Going to give the edge to the 5x9 in the depth department. Currently have both coils mounted on their own lower rods for a quick swap.

Finding the Impact works great hunting for CA clad. Canadians should not overlook the Impact. My wife wants a freezer, looks like the Impact's finds will pay for one before seasons end. LOL

By the way, love finding silver coins, kind of scarce around here...you can buy more silver coins than you can find with the clad found. Always on the look out for that buried gold jewelry item as my main objective, will take all clad as a bonus.

 

[dfmike]

Thanks Sven for your detailed report.

I never thought about being attentive to different audio responses while pin pointing. I will try it out. It is clear to me by your input on the Impact that it ID's Canadian clad differently than the CoRe but I can say that the CoRe is the best detector I have found so far for getting the steel core nickel plated coins we have here (I have not used the Impact yet). On DI3, the audio alternates between mid and high conductor tones and the sound will break into a squawk and distort at the top or bottom edge of the coil. On pure metals, the sound will remain true and just disappear into silence on edge.

One thing I have noticed about this Nokta detector is that headphone selection in DI3 is critical. I can more clearly identify the differences and slight nuances in tones with 2 of my headphones, not the other most expensive one which I would almost always use with my Fishers.

 

[Sven]

I use a set of Killer b's that I modified with Turtle Beach x31 headphone speakers. Best speakers I have run across.
At one point I was able to buy used (store demos) wired x31 headsets for $5 each.
You can still pick up just the wireless headsets on ebay cheap if you just want the speakers.

The x41 has larger speakers.

 

[Monte]

headphone selection is going to be an individual thing based upon how well we hear, or don't hear for some of us. Sometimes the speaker impedance can make a difference, but it doesn't stop there. The electronic circuitry used in many headphones also can help, or hinder, the audio performance. My preferred wired headphones are the Killer B 'Hornet' which are more comfortable than the Killer B 'Wasp' or similar SunRay Pro Gold models they also make. They use the same 150 ohm speakers, but the 'Hornet' model uses the tank style ear cups that more fully cover the ears and don't press uncomfortable on them. They block out more nearby noise as well.

I can say that the CoRe is the best detector I have found so far for getting the steel core nickel plated coins we have here (I have not used the Impact yet). On DI3, the audio alternates between mid and high conductor tones and the sound will break into a squawk and distort at the top or bottom edge of the coil. On pure metals, the sound will remain true and just disappear into silence on edge.

Ferrous / magnetic metals can be a challenge for many detectors we use these days, or really over the past 30+ years, and even more of a challenge when using a Double-D coil. For peak efficiency and target detection we really need to sweep over a target with the center axis of a search coils, regardless of type [size=small](Double-D or Concentric)[/size], then learn the effects of ATC [size=small](Audio Target Classification)[/size] and the benefits we can gain from it by sweep technique.

What you are referring to here is one of two techniques I have been using and teaching since the early-to-mid '70s, and especially with motion-based Discriminators since the late '70s and very early '80s. The two techniques I coined the term for are 'Quick-Out' and 'EPR', an abbreviation for 'Edge-Pass Rejection.' With most Concentric coils the 'EPR' responsive area it usually at, or just inside, the outer 1" or so of the search coil from any direction. With a Double-D coil, the responsive area can vary from just inside the outer-edge of the coil to possibly 1" to 2" outside the outer edge of the search coil, front or rear/tip-or-tail of the coil.

An iron object [size=small](or other ferrous-based or magnetic metal)[/size] might give off a mixed audio and visual read-out when swept across with the center-axis of the search coil, often fooling the detector operator with an up-scale an d errant read-out. Especially with a DD coil and a target such as a bottle cap that might 'read' as if a US cent or dime or quarter. Using the 'EPR' technique, ferrous objects will produce a 'proper' negative or proper low-town or Iron ID visual response. That's one of the challenges when searching locations with coins that are not made of a noble metal, such as the steel, iron, and nickel metal coins found in some foreign countries, such as most found in Canada.

One thing I have noticed about this Nokta detector is that headphone selection in DI3 is critical. I can more clearly identify the differences and slight nuances in tones with 2 of my headphones, not the other most expensive one which I would almost always use with my Fishers.

The Di3, or Three-Tone, search mode is one of the best for use in iron infested sites as it can provide a very good audio 'signature' on targets of mixed metal or ferrous based metal make-up. For Relic Hunting around rusty tin it is my favorite search mode for that very reason.

And as I stated, I prefer my corded Killer B 'Hornet' headphones, or in this heat and hunting in dense brush, I use the 2.4 Gig. wireless Nokta headphones with my Impact models.

Monte

 

[dfmike]

Thanks Monte and Sven.

 

[Tom Slick]

Monte - I have to agree that the Killer B Hornet is an excellent set. They are my favorite when conditions allow me to use them, but here in AZ that happens only a few days a year. With the heat, I'm usually using headphones that are quite a bit cooler and The Makro Wireless fit the bill for me.

 

[Monte]

Monte - I have to agree that the Killer B Hornet is an excellent set. They are my favorite when conditions allow me to use them, but here in AZ that happens only a few days a year. With the heat, I'm usually using headphones that are quite a bit cooler and The Makro Wireless fit the bill for me.

We have had a very long, and very hot summer here in Eastern Oregon, but I'll agree that your Arizona life has seen it even hotter far more regularly. That's why I am planning my week or two 'vacation' your direction for November or later.

But I have done a lot of hot summer hunting after the sun is gone for the night, here in Oregon as well as many of my summertime hunting I have done in Utah, Nevada and Arizona in the past couple of decades. Most of my night hunting I wear the corded headphones with most detectors, preferring the Killer B 'Hornet' model. I'm going to get another set of 'Hornets' to have along as back-up, which is what I have with my Nokta 2.4 Gig. wireless headphones for the Impact. One regular-use set and one as back-up that I keep fully charged and ready. On these hot summer days they are such a comfortable option and work well.

I often use a different detector for competition hunts, but our club potluck and competition hunt in Utah is a week from tomorrow and considering the heat we're dealing with, I'll likely be using the wireless headphones to complement the excellent performance of the new 7" Concentric coil on the Nokta Impact. A great combination of performance and comfort.

 

[BrianGaston]

Hello! I know this forum is a little old and I am not sure if this question is appropriate for this forum, I apologize if is not.
I was thinking of getting the nokta anfibio multi and was wondering if it would be a good md for hunting modern parks with modern type trash like bottlecaps and pull tabs, is the audio response enough totell the difference between a good target and trash, ofcourse with some experience?

Thanks in advance, Brian...

 

[BrianGaston]

Hello! I know this forum is a little old and I am not sure if this question is appropriate for this forum, I apologize if is not.
I was thinking of getting the nokta anfibio multi and was wondering if it would be a good md for hunting modern parks with modern type trash like bottlecaps and pull tabs, is the audio response enough to tell the difference between a good target and trash, ofcourse with some experience?

Thanks in advance, Brian...

 

[Sven]

Those are my usual hunting grounds. Perfect detector for those situations. But, like any other detector, its not foolproof. Learn how to operate it, listen to the tones and watch the target ID numbers and you will be digging less trash. The new 11" DD search coil does very well, better than expected in the trashy hunt sites. But, I prefer the 7" concentric.
You will not be disappointed with the Anfibio-Multi if you choose to buy one. There are many posts and videos to read and view that show off its performance.

 

[u2robert]

What kind of depth are you getting with the 7" coil?