The Validity Of Small Searchcoils

[Bob S.]

The other day I ventured into a not so hunted area of my permission. It is a steep hill on the backside of a cut stone foundation... No doubt an embankment where the inhabitants tossed their discards long ago. The incline is tough as is the ground. The ground there is like cement as large Locust trees help shield rain. The finds were not deep, possibly the deepest being 6", but the entire hill side is blanketed with small square lathe and framing nails. I generally don't use discrimination on my Apex and I hunt with wide open sensitivity. I listen for pitch level and watch display readings. My iron volume is set lower to "2" allowing me to hear the nail concentrations, but keep my sanity.

I have always liked Garrett's elliptical searchcoils starting back with the AT-PRO for their shape, quality of construction, and the ability to hunt closer to objects like rocks and trees. Today I was hunting with the elliptical stock coil "Viper", 6 x 11". When I first purchased the Apex, I did some air tests to see the extent of the coil's unfettered electromagnetic reach and I was surprised to get a small clear signal on my custom 14K gold wedding ring at a measured 14". Hunting the embankment was difficult. You lay the detector down, it wants to slide down the hill along with yourself and your digging tools, but the chances of finding targets here was fairly good. In one hour I found the targets in the first photo below. The targets were tough to discern mixed with the nails given the Apex has only one processing speed... But that speed affords good depth amongst target concentration.

Two days later I would saddle up Garrett's smaller elliptical "Ripper" coil (5 x 8") and head back to the embankment. It was a calculated purchase awhile ago, but I had yet to really give it a workout. As a side note, before I left I did the same same air test with my wedding band and was again surprised to find it had nearly the same reach as the Viper coil. But how would it do given the smaller footprint? As a test, I carefully hunted the exact same areas to see if I could define more targets amongst the chatter. As you can see in the photo below, I found twice what I found before! Signals were easier to confine and all were found at the same depths as the stock coil. The spoon was actually buried vertically with the bowl deepest in the ground. As I brushed the leaves away I could just see the handle's back edge at the surface.

Even though the Viper coil weighs about 1.0 lb., it is still nice to swing in high grass, but the little Ripper (0.8 lbs.) is an absolute crowd pleaser! Less resistance to grass and weeds and the depth is not too far from the Viper. What I came away with from those two days is the Ripper forced me to hunt with a slower swing speed given less ground coverage. Slower works well to give the Apex more processing time between crowded targets... Also, not as much depth loss as detectors with higher processing speeds. I would not want to hunt farm land with smaller coils because the matrix is not as crowded and you might miss those targets on the fringe of detection depth. Cellar hole grounds is where the little "Ripper" rips it up!

[kac]

Large coils don't usually offer that much depth and the larger footprints will make it difficult to pick out targets between trash. Last few years as wifi and cell signals get stronger I am finding the smaller coils generally outperform the larger and only at the cost of ground coverage. Buddy mine does extremely well with his Ripper on the Apex. Generally his main coil except when we hunt in open low trash fields or beach combing.

Really nice run, bet if you go over it you will pick out more targets.

[JCR]

Garrett has always made excellent quality coils. The 5X8 is one of their best for versatility and performance.  Understanding what to use when is key. 

[Doc Bach]

Great topic Bob and that looks like a fun and productive relic site.

I've never used any of the new Garrett lineup of coils but have been reading about and hearing good things from an old digging buddy in regards to the Viper and Ripper coils.

However I do have a 6.5 X 3.5 NEL SNAKE and a 9.5 x 5.5  CORS FORTUNE that I run on my A/T GOLD and MAX with the CORS being my favorite.

Your post prompted me to put fresh batteries in my AT/Gold for a dig on Sunday and give the Deus 2 a rest.It seems like everytime that I hit a tired old site with a diffirent machine and or coil the places comes back to life.

 

[Lodge Scent]

Nice work there Bob! You don't have to sell me on the effectiveness of a small coil. Way back in my Whites DFX days, the little 4X6 coil would always get a turn at the iron infested cellar hole sites and it would always sniff out some goodies that the larger coils couldn't hit.

[IBMe]

This is my #1 topic right now. On a fluke, I put the round 5-inch coil on an F75. All of a sudden, I’m hitting coins all over the place in areas I’ve been through with every detector including nox, orx, D1 and Legend.

But this causes a big problem. How can I go out with any other coil knowing I’m going to be missing targets?

[Lodge Scent]

8 hours ago, IBMe said:

This is my #1 topic right now. On a fluke, I put the round 5-inch coil on an F75. All of a sudden, I’m hitting coins all over the place in areas I’ve been through with every detector including nox, orx, D1 and Legend.

But this causes a big problem. How can I go out with any other coil knowing I’m going to be missing targets?

That is just a fact of life IBMe. Rest assured that you are missing targets with the 5-inch coil as well. No single coil will find everything.

[Bob S.]

Thanks everyone! Truthfully, I have always resisted small coils in my early days because the ground depths of my average targets have always been close to the diameter of the searchcoil. But today's quality of windings and potting seem to foster a more sensitive and stable transmission. Having spent only hours in this experiment to experience what I did puts me in a mind frame to use the small coil even more now.

I like to hunt usually from 4 to 8 hours when I can. The other attribute and reward of the smaller coil is you can do that hunt time with a less hurting shoulder afterwards. After 56 years of swinging heavy, I feel blessed that I still can... And a small coil really hits home in that regard. The Viper coil is my all-around favorite for good depth and maneuvering tight places in the woods, but the Ripper will definitely see more use in those same places... I can literally hunt all day with way less fatigue using the Ripper that is about a 1/4 pound lighter.

Yes, as Doc Bach says, switching to a different detector and coil can open ground to more finds! I experienced that recently using my Troy X2 and Super 7 coil. I also believe every time you re-hunt an area you should also put yourself in a different frame of mind, even if it is the same detector/coil setup. A lot that limits us is the "boredom factor" or the "I can hunt this acre in ten minutes" syndrome... No we can't. I have been hunting this particular permission now for 13 years because of its vast size. The law of diminishing returns is now starting to apply, but just having the discipline to know you can eek out one more coin or button and enjoy the outdoors on a crisp Fall day makes it all worthwhile.   

[EL NINO77]

we all know that in certain detection areas the ground is not prepared... and so the number of non-ferrous targets decreases with each detection... when we reach the point... when we no longer find any specific targets... with a detector on a standard,, or larger coil. ..

The detector on these coils has really good detection-separation parameters... but such large coils have their physical detection limits, especially if there is denser iron waste in the field, or a certain type of mineralization... and it is clear that some good targets are blocked by these coils ...

Now there are only 2 options left...
We will either use some other - better detector, which theoretically can detect better... or we will use our detector with a smaller coil... which can significantly better separate some targets between iron...

and a smaller coil can play a very important role in this type of detection.. of course, an adequate setting of the detector is also important in this situation..

The Monte performance nailboard test can be a good help...how to find out which detector setting and how quickly moving the coil can still well unmask the target between the iron in such a test...

Even according to my experience, I created an even more difficult iron test ... where the size of the coil plays an even more important role..

I admit that such a detector setting was worth using in detection more than once...