Randy, I have been a bit busy with some travels the past month to make the
'5th Welcome-to-Hunt Outing' in Nevada and a the
6th WTHO just concluded here in Eastern Oregon yesterday. While I used both my Nokta FORS CoRe and FORS Relic a lot, because I know them and can depend upon their in-the-field performance in very dense iron contaminated sites, it also gave me some opportunities to work my Impact in both side-by-side comparisons with similar-sized coils and operating frequencies.
Then I also worked it in the very dense iron nail infested places with my two smaller-size coils to even better confirm the results I got earlier on a very challenging
Nail Board Performance Test as well as hunting with it in a ghost town, CCC Encampment and at a WW-II POW camp.
RANDY CONNELL said:
THE IMPACT ON THE PRO PACKAGE CAME WITH A SMALL FOOT BALL SHAPED COIL, ...
Yes, that is the 4X7½" DD coil which I like ...
for a lot of urban Coin & Jewelry Hunting uses where it is a bit trashy. I used it initially in some regularly-worked ghost towns and other old-use locations that have a lot of iron nails, often in a very close relationship. I also worked it in some old areas that have a dense amount of rusty tin, from can-size to hunks of bans, to small and very small bits of that annoying rusty ferrous trash.
In-field comparisons with other detectors in my Regular-Use Detector Team, the Impact did passably OK with that small elliptical coil when the trash and non-ferrous targets were located sufficiently apart, and when the non-ferrous targets were not smaller than a US 1¢ small-variety coin. In a side-by-side comparison with my Tesoro models and Nokta FORS CoRe and FORS Relic using their smaller-size search coils for hunting dense iron nail contaminated sites, the Impact w/4X7½" DD got 8-out-of-8 on the
NBPT when using a modern Zinc 1¢ or older Indian Head 1¢.
However, in a very challenging scenario, using my
NB and a very small and thin 1836 Capped Bust Half-Dime, the FORS CoRe w/
'OOR' DD coil did the best, and the FORS Relic came close w/7-out-of-8 and an 'iffy 8th response. The Impact w/4X7½ DD failed to get the minimum 6-of-8 to pass the test. Matter-of-fact, on that particular challenge scenario, it only managed 4-out-of-8. The reasons? Mainly due to the internal wire winding sizes and shapes of the Tx and overlapping Rx coils, and perhaps a bit in the Impact's circuitry design.
Do most folks encounter the really nasty, very dense/close relationship scatterings of iron nails? No, I don't think so. Do such ugly conditions really exist enough to be concerned about? Yes, most definitely, and if you haven't had to endure such terrible conditions of nails, accompanied by more piece of rusty tin than you could imagine, just get a hold of me and I'll take you to several old sites I hunt to day, and some I have hunted since 1969, that can shock many metal detecting hobbyists with such a tough challenge.
Anyway, the new small elliptical coil is a very good coil, don't get me wrong, and I have used it with success in low-to-modest trash environments, and it is my favorite small coil to use for typical urban Coin & Jewelry Hunting. My 'Test' Impact is now my dedicated Coin & Jewelry Hunting detector, sporting the 4X7½ DD when working typical urban Coin Hunting sites, and dealing with a lot of modern non-ferrous junk such as foil, tabs, etc.
I plan to have a production Impact as well to have a pair of Impacts, just as I do with my two CoRe's and two Relics, keeping different search coils mounted full-time for their primary use and ready to grab-and-hunt. When I get it I will mount the 4X7½ DD on it as my primary-use Coin & Jewelry Hunting unit for most urban sites, sports fields, and beach work, mainly on freshwater beaches in the areas where I live and travel the most. There will be some work on very salty beaches, and for my beach hunting and working low-to-modest littered sites I will likely use the 5X9½ DD open-frame coil when it is in production.
At that time my 'Test' Impact will be my dedicated Relic Hunting Impact for ghost towns, homesteads, pioneer and military encampments, gold mining and logging camps, and other out-of-the-way places where I most frequently encounter a lot of dense, closely-located nails, rusty tin, and other discarded / decayed ferrous debris. It will also be the Impact that I grab when working urban settings with a lot of nails and other very iron littered junk, such as sidewalk renovations, building tear-down sites, etc. This Impact will keep the small, round 5+" DD mounted full-time, like I have been using on the last two
WTHO's where iron abounds in very unkind amounts.
RANDY CONNELL said:
... IS THERE A BETTER SMALL COIL FOR IT OR IS THERE A NEW ONE COMING OUT? I WANT IT FOR IRON INFESTED AREAS.
Yes, there is. At least there is at the present time mounted on the end of my 'Test' Impact's rod.
After reading the results of the "
Monte's Challenge .... and surprising results" posted by Oregon Gregg on the AHRPS General Metal Detecting Forum on 3/7/'17 [size=small]
(which was not intended to be a Forum Post but just a friendly get-together between Gregg & me to show him a very tough challenge)[/size] it generated an almost immediate contact from Dilek at Nokta / Makro Detectors.
We discussed the results of that difficult challenge and the reasons I felt the Impact struggled on that test. While some detectors can have a little difficulty due to the circuitry design and programming, a lot of the issues that arise in very dense iron contaminated sites with closely-located desired targets that are masked or partially masked are more search coil related. In this case, I attributed the main problem to be the inner Tx and RX windings, their size, shape, and amount of overlapping that was used, combined with the Impact's circuitry design.
Among other things we talked about, we discussed a coil size and type that might provide improved performance from the Impact in a really difficult close-nail condition. The Nokta engineering team went to work and on the Forum Dilek posted the following message on April 5th:
"Hello Monte!! Regarding this subject - A small round coil for the Impact has been developed for your nailboard testing and it will be on its way to you soon."
They made one for me to work with to evaluate performance and kept another specimen in-house. My report back to Dilek was very positive as it vastly improved the Impact's results on the
NBPT using the dinky-sized silver Half-Dime, as well as working it afield in two very nail infested ghost towns that date to 1863-1870. That was followed by an e-mail from Dilek who gave the 'OK' for me to mention this 5+" diameter DD coil, and also announce the following:
"OK Monte, based on your suggestion I will announce this as an optional coil BUT we are still backordered on the Impacts and other coils so I will wait for a while.
You can post your results though – please make sure that you mention that we developed this coil upon your request and for your nail board test …and now that the results are positive we are thinking of adding it to the lineup but you do not know about the date.
Dilek"
With this coil and using the Impact's Frequency selection, I can work at the default 14 kHz and get performance on comparable tests similar to what can be achieved with the 14 kHz Makro Racer or Racer II or the 15 kHz Nokta FORS CoRe. I can also opt for the 20 kHz frequency and get very comparable results as I get from my 19 kHz Nokta FORS Relic.
[size=small]
NOTE: As a rule I do not post personal e-mails I share with any manufacturer, with an exception like this where I had the Okay from Dilek to share the results of this prototype 5¼" DD search coil.
Also note that Dilek said it will be a while because they have to get Impacts and other search coils in-the-works, and they are thinking of adding this coil and will announce the date on the Forums.[/size]
RANDY CONNELL said:
AND IS IT REALY WORTH THE EXTRA COST VERSES THE FOOT BALL SMAL COIL?
In my opinion, absolutely YES! As I stated earlier, the small 4X7½ elliptical DD is a very good coil for a lot of detecting applications, and it is a small coil that has worked well for me in a lot of 'traditional' Coin Hunting types of sites when dealing with typical modern trash. But if we are talking about sites that abound in iron nails and other closely-associated ferrous targets especially, the round 5+" DD coil improves the unmasking capability of the Impact. Owning such a versatile detector means a dedicated avid detectorist would also want to own search coils that complement that level of versatility, if needed.
Monte
)[/size]
