I admit I don't use my Sun Ray 5.5" coil (actual size) as much as I should since I bought it. I've strapped it on maybe 4 or 5 times and didn't even hunt all day with it. But in that time I did dig a silver rosie about 7" deep that was right in between two shallow pull tabs. I was pleased because this particular old park is super trashy and hit so hard by everybody for years that it's been a couple years since I pulled a silver out of it, although I had only hunted it maybe 4 or 5 times in those prior few years to be fair.
The rosie banged so hard that I think it could have easily been 9" or maybe more deeper and I would still have got a good hit on it. That's impressive, because in that particular soil the best of my prior non-Minelab machines could only muster about 7.5" max on a silver dime in that soil using an 8 to 10" coil, so it appears that tiny little Sun Ray is getting deeper.
I'm so hooked on the left/right super separation abilities of the 12x10 and it's depth that I can't seem to force myself to break away from it, as I've been impressed at how well it will separate stuff left/right wise and so don't feel I'm missing too much. Of course I know that the Sun Ray will find more in heavy trash just alone due to it's shorter DD line from tip to tail though.
These little coils have their place for heavy iron or trash. At sites where I know silver can't sink past say 7 to perhaps 9" and are heavy in trash or iron I need to start forcing myself to strap on the Sun Ray because that is where it should shine above all other coils. No sense in looking for super deep silver at some sites where coins can't sink past say 7 or 8", as that is well within the range of some non-Minelabs in my soil. It's the sites that stuff can sink deeper when I should be wasting my time looking for coins out of the reach of other detectors, and the fact that the 12x10 pushes things even deeper is why it should be used at such sites. At those kinds of sites there the stuff is shallower if I am using my 12x10, I logically there aren't deeper coins out of the reach of a few other non-Minelabs, so if I am using a bigger coil at such a site I should be spending my time digging more iffy or one way coin signals as those are all that is left that most people won't dig.
But for the shallower coin sites with heavier amounts of iron or trash logic dictates the Sun Ray would be the perfect coil. Coins well within it's reach, and the potential to find the worst masked of coins that a larger coil might not be able to.
For a large coil I like the SEF's shape because it's shape is an attempt to increase depth while at the same time increasing left/right separation. But for a trash coil my thinking is the reverse of that. For a tiny trash coil my primary motivation is max separation, so I personally don't want a coil that is longer than it is wide. I know that's an attempt to increase depth while maintaining excellent separation, and I know the 8x6 excells in that respect and is a fantastic coil, but for me personally when I want a trash coil that means the smallest round coil I can find for max separation ability. The Sun Ray sure is tiny at 5.5" in diameter so I'm well pleased with that. However, The Excelerator 5" coil is actually a bit smaller than 5", so if somebody wanted the smallest diameter coil possible they might want to look into that coil. I don't know how it compares depth and stability wise to the Sun Ray though, but I do hear good things about it and would like to try one.
If I were to want a odd shaped trash coil, I saw somebody mention this once and it really intrigued me. How about a 2" wide by about 4 or 5" long trash coil for extreme separation (2" wide) while attempting to maintain pretty good depth? I think that might be a real good seller for somebody on these Minelabs. In that case I'd be willing to "trade off" a little separation ability with the longer length, because that length is still as small as anything out there, but the 2" width might take separation a bit further than when even thought it could get. That said, I don't see how it can get much better than the Sun Ray.
I found out the Sun Ray is a true 5.5" coil as it's filled with epoxy, so the windings don't need padding at the edges to protect it from shock when bumped into something. Some solid coils that aren't filled with epoxy are padded around the outside, so they aren't the true physical size of that coil. An 8" coil, for example, can be 7 & X amount of inches in true size because the windings are what really matters in that respect and aren't going all the way to the edge of the coil.
I wonder if the 5" Excelerator (which measures a bit smaller than 5" on one side of the coil anyway) is filled with epoxy and has it's windings going all the way to the edge, or whether it's not and so the windings are padded against shock and so even smaller than it's actual size. Usually epoxy filled coils are rated waterproof while ones not are rated water resistant. Does anybody know which the Excelerator is rated at? Another way one might tell is to mush the coil with your finger on top and see if it's solid or gives a good bit.
PS- One other tip for a little trash coil. They aren't just useful for heavy trash. At sites with tones of tiny hot rocks or black sand pockets causing off and on nulling a smaller coil like this can "see" between" those null spots and pull better IDs out of coins that might otherwise either null on you or be a very bad signal that you might pass on. I had used the Sun Ray at one such spot, near a gravel road where the gravel sprayed into the nearby grass was causing my machine to null out here and there. The Sun Ray was able to work that area without that annoying nulling that my larger coil was experiencing due to the stray gravel in the area. A smaller coil can also improve ID at depth on targets in some of the worst ground where even a Minelab has trouble handling it. By using a small coil you are taking in less ground "stew" and it is less prone to wash out a target's quality at depth. For that reason there are sites where a smaller coil will get deeper in reality, even if the site isn't loaded with iron or other trash but simply has a bunch of bad minerals in the matrix.