SEF 15x12- Are You Setting Your Machine Up Differently For It?

[Critterhunter]

I've a Sovereign GT user and thus far I love the 15x12. My only suspicion thus far is that I have yet to dig any coins deeper than I have with the stock 10" Tornado. Recently I figured out that maxing out sensitivity to the edge of stability on the GT does not mean best depth, regardless of coil used. I also noticed this with my prior Explorers. Even if the machine seemed stable or I was riding on the edge of stability with coin garden testing I found to my surprise that the coin might null or at least severly degrade in target quality. Often something much lower, like 1/3rd sensitivity will give best response and maximum depth.

Anyway, I'm hoping that now that I've discovered how to properly calibrate it for best depth I'll start to see greater coin depths than I've got with the 10" Tornado. Deepest coins I've dug with that coil have been about 11" or so. My concern is that most of my sites range from medium to high in mineral content. Although I know that in tests done on the web the 15x12 was deeper than the 12x10 on dime sized targets or larger, I'm concerned that this coil might be too large in that it's seeing too much ground matrix and thus washing out the target, equalling less depth. Not that this coil isn't stable. I can run sensitivity higher with it than the 10" at some sites, but as said I've found that with any coil on the FBS and BBS machines max stable sensitivity doesn't usually equal max depth. Something much lower often will.

So my question to you Explorer users is if there is any changes you have to do in setting up your machine versus using the stock 10" or 11" coils. I'm thinking perhaps gain or some other setting may allow this coil in high minerals to get deeper than stock but that it's not going to on my GT lacking that control and being in high minerals. Still haven't proven this one way or the other yet. It may be deeper than stock but I have yet to see it.

 

[Critterhunter]

So nobody has anything to say about whether they change anything in particular on their Explorer when using the 15x12. Again, I'm curious if you guys are adjusting anything besides sensitivity in at least medium to high minerals in order for this coil to achieve deeper depths. My main concern is that as of yet I have not dug any coins deeper with it than the stock 10" Tornado coil. With that coil I've dug a few coins at about 11" that sounded and ID'd great. I'm thinking that perhaps in my medium to high mineralized sites the 10" will achieve better depth because the 15x12 is just taking in too much ground matrix. I'm not talking about stability/max sensitivity here because I'm finding I can run the SEF coil at even higher sensitivity settings than the 10" at some of my sites. But, as also said, I've found that regardless of which coil I use maximum depth/best ID is often acheived with a sensitivity setting that is much lower than what max stability is. What I'm thinking is that if I don't sooner or later prove to myself that this coil is deeper then I may pick up the 12x10. Perhaps with that coil seeing less ground load it may show improvement over the stock 10" in terms of depth.

Not that I'm not very happy with the 15x12. It seems to separate and pinpoint better for me than the 10" and it also seems to like finding coins on edge. I'm also impressed with how many coins it's unmasked for me even in heavy trash. It's smooth as butter in operation and without the coil cover (which weighs 3.6oz) it's the same weight as the 10" Tornado with it's cover still on.Using the bottom of the "V" at the tip of the SEF coil it pinpoints like a laser as well. It's sensitivity to even tiny objects like shoe lace rivets at depths of 9" or more is also very impressive. For that reason alone I would expect this coil to get coins well past 11". So far the deepest "coin sized" object I've dug with it was a lead sinker at about 11" deep. It's diameter was less than that of a dime so once again that tells me it should have no problem hitting coins this deep and deeper.

In summary though, perhaps in my higher mineralized soils the target is just getting washed out too much with the large ground signal that the coil is seeing and thus it isn't getting as deep as the stock 10". If that's the case then the 12x10 and perhaps the S-12 might be the maximum size I can go while still getting deeper coin targets. If I find out from a few of your Explorer or Etrac users that you have to adjust something much differently on your machines when using this coil then that would indicate to me that there in lies the problem lacking that function. Regardless, even if this coil isn't as deep or deeper I still love it for many other reasons and for sure it's coverage has found me coins that I might otherwise have missed.

 

[JW]

n/t

 

[Derrelld]

I don't change a thing. Sometimes I will lower the sensitivity to adjust with interference. Just put the bad boy on and go detecting. The thing is a vacuum cleaner.. You don't miss much with it! I have the 10x12 and the 12x15.. Both coils are awesome.. I truly believe a coin you pick up with one, you will find with the other.. But you have to use your ears and go slow.. The 12x15 is a great tool in those open areas or ball field, and I will hardly take off my 10x12 in the park..
If you have the money.. Both are great tools to add to your collection!

 

[Critterhunter]

Thanks for the info on the fact that you aren't changing anything other than setting sensitivity of course on your Explorer. Yes, the 15x12 is an awesome coil. In every respect on my Sovereign GT I think it's better than the 10" Tornado, which is also one of the best coils I've used on any machine. But the SEF feels like it separates better despite it's size, it pinpoints better, it seems even more sensitive to tiny objects like shoe lace grommets, and it even seems more stable in iron or rough ground. Of course the coverage is great, and with the coil cover off (I use spray on bed liner) this coil weighs exactly the same as the 10" Tornado with it's cover still on...so weight isn't an issue either. This coil also seems to get coins on edge and unmask some in trash better in certain respects than your convention concentric or DD designs.

My only concern is will it get deeper in my mainly medium to high mineralized soils than the 10". Thus far the 10" has got me coins at around 11" deep with perfect audio/ID. The max thus far I've dug coins with the 15x12 has been roughly about 8 to 9" or so, also with good ID/audio. Most of my experience using this coil (and the GT in general using either coil) has been setting it up like most machines to achieve maximum depth. That being the tradition adjustment of sensitivity right on the verge on instability. Just enough falsing to deal with in the hopes of punching as deep as possible. What I've found out through coin garden testing and such, however, is the same thing I used to find on my Explorers concerning sensitivity adjustment. That being that riding the edge of stability (at least in my soil) does NOT provide maximum depth. It will degrade or even null the coin out if you push sensitivity. unlike what is traditionally the norm on most traditional VLF detectors (maxing it out to the edge).

What I'm saying is that since it's only been a few months since I've re-learned this lesson that applied to my Explorers and found it to also be true for the GT, I don't have much field time yet on properly calibrating sensitivity. For that reason I still have high hopes that this coil will show improved depth over the 10", not that the 10" on the GT isn't already impressive in that respect. I mainly am just hoping that along with the all around great advantages to this SEF coil that I can add improved depth to that list.

I have dug shoe lace holes at 8 to 10" with it and even a sinker smaller in diameter than a dime at 11", along with several other tiny bits of metal at depths of about 11" or so. They hit hard and for the most part ID'd like they should have for what they were, so that tells me that if this coil can hit little targets at those kinds of depths then it's only a matter of time for me to start seeing coins that deep and beyond. Of course you've got to hunt a site where the soil conditions allow for deeper targets and that further limits my experience with this coil since I have hit those sites even less thus far with my new "best" method of sensitivity calibration.

If after a proper amount of field use at deeper coin sites I don't see deeper coins than I've dug with the 10" then I will be forced to conclude that at least in my soil the 15x12 is beyond the point of diminishing returns in terms of size and increased depth. If that's the case I'd at least still expect it to get deeper in my low mineral sites. Regardless of how the depth issue pans out this coil is still deep (even if it turns out not to be as deep as the 10"), and I've very happy with it in all other respects. It's coverage and what looks to be better ability to hit old coins on edge where other coils and machines weren't able to more than makes it a perfect 9.5 on a scale of 10 in my book. If I see deeper targets with it than the 10" then it will bet that perfect 10. Coverage in large areas like the beach or open fields has got me coins I probably would have missed, and as said it seems to unmask coins in trash or iron better or at least being better at differently masked targets than most conventional coil designs. If you in the camp of maxing out sensitivity when I was doing that I found that often this coil would allow higher sensitivity settings than the 10" at the same sites. It's that smooth and well designed.

Bottom line is if I find out this coil *in my soil* isn't going deeper than the 10" (it's at least very close in depth thus far but hasn't pulled ahead...yet) then you can bet I'll be picking up the 12x10. Perhaps that slightly smaller coil seeing less ground will increase depth over the 10" without going past the point of diminishing returns in terms of seeing too much ground matrix. Remember I'm talking in my soil here. Most of my sites are medium to high in minerals, but I do have some low mineral locations as well. Everything I've read about the 12x10 from most people says it's just as good in all respects as the 15x12 so I'm confident I'll be happy with that coil as well.

As a sidenote about the sensitivity calibration (which might be of interest to Explorer owners because I found it to be true on those machines as well when I owned them), I'm finding that at little as 1/3rd or 1/4th max sensitivity provides the best depth and target IDs in my tests. I've taken to calibrating the machine at fringe depth on targets at each new site I hunt and often find about 1/4th sensitivity (about 2PM on the Sovereign dial...which goes counter clockwise) ends up being the best setting. This is WELL below what anybody would consider to be a stable machine in terms of threshold.

Anyway, with you Explorer owners telling me that you aren't using any special setting for this coil compared to your other coils then that tells me the potential is there for the depth. I was concerned there might be a certain adjustment to take best advantage of these coils that the GT doesn't offer. Looks like only time and field use will answer the question of it's depth. Thanks again.