KellyCo Now Carrying The New 13" Coil For MXT & M6. Asked About It For Sovereign.

[Critterhunter]

http://www.findmall.com/read.php?25,1674335

I shot JW at Kellyco a PM asking if they are going to request Detech make this coil for the Sovereign too. I would think that they'd want to because I would bet with the Sovereign being made for MANY years, with many different models of it coming out over that time span, that there are probably many more Sovereigns floating around out there than the M6 or MXT.

Bryce in the Explorer forum is supposed to post a field report soon comparing this coil to the 12x10 in terms of depth and other things. I would expect the 12x10 separates better because of it's unique design, while this 13" coil appears to have a more conventional (round) DD coil design that probably wouldn't compress the width of the detection line like an SEF does. But, I await anxiously to hear from Bryce if he is finding this coil is deeper than the 12x10. On the other hand, that probably depends on if his soil is more mild than mine. The 13" coil might be soaking in too much ground matrix (degrading the target signal) to show improved depth in moderate or heavy soil mineralization...While the 12x10 seems to ride on less ground for me (width wise) than even the 10" Tornado, and thus allows higher sensitivity settings, is more stable, and isn't as prone to washing out the target signals at depth like a bigger coil might in minerals.

I will report back when I hear from JW at Kellyco. I would suspect that KellyCo can request from Detech to have certain coils made for specific detectors based on what they think would be a good seller, and that amounts to how many people out there own that model. The Sovereign, having been made for years, would have to be worth making one for I would think.

 

[stumppass]

Ok, here is my take on the 13

 

[Critterhunter]

I'll buy into those theories....Or at least hope Minelab makes a new BBS machine with a Pro Coil or some other larger coil to push it's depths even further than the already excellent depths the 10" Tornado gets. I can see why you might think the Pro Coil was made by Detech, or at least designed for Minelab by them, because you're right that 13" coil sure does look a lot like the Pro Coil...And is very light like it as well.

We're probably both wrong, but it's fun to speculate, ain't it?

When you come to a point in detector technology that is so advanced, such as the Sovereign, it's hard to develop something that goes even deeper based on the limits of VLF (Minelab multifrequency is still based on the physics and limits of VLF technology...Although of course much improved and superior to the single-to-three frequency VLF machines made by other manufacturers). That's where you have to start to look for any other ways to improve depth, and about the easiest way to do that is to make a good quality larger coil.

I believe much of the improved unmasking abilities and depth of the Etrac or SE Pro over the older Explorers is mainly due to the Pro Coil. It's an excellent coil with good separation. I've read many old Explorer owners say that the Pro Coil or 12x10 on their older Explorers have made the performance just as good as a new machine. Don't you think it's curious that Minelab would even come out with an 11" Pro Coil on the SE or Etrac, when they already had the stock and production machines to build the 10" coil? Why go through all that extra expense if it didn't matter? They probably did because a slightly bigger coil equaled more depth, and as said it has better separation than the older 10" coils did.

There of course comes a point in size where a coil actually starts losing performance. Less separation ability (which can be got around and even improved over a smaller coil with something like the unique field dynamics of the SEF coil), taking in too much ground matrix and thus washing out or degrading target signals...Equalling less depth than a smaller coil (again, can be got around in some respects such as the tighter less "fuzzy" detection field of the SEF soaking in less ground stew), and then there's just the plain simple fact that when a coil gets too big it no longer has good sensitivity to coin sized targets.

For DD coils it appears that the limits in coil size while still retaining good coin sized target sensitivity appear to be around 14". You don't hear too many good things about the Detech 16 or 18" round coils for coin shooting, while you do about the 14" WOT. So I would guess 14" is probably about the limit.

For concentric coils I've always heard they don't retain as good of coin sized target sensitivity as they get bigger as well as a DD coil, and it appears the limit for a concentric is probably 10"...MAYBE 12" max. I've rarely heard any positive increases in depth about 12" concentric coils. Part of that is also due to a concentric riding on more ground matrix than a DD, so a 12" concentric would probably have to be used in some very mild soil in order to really show any improvement.