Still Need Input- Deepest Of Larger Coils For Coins?

[Critterhunter]

I realize I've beaten this to death over the last few months but I'm still looking for opinions on which of the larger coils anybody feels is the deepst on coins without losing sensitivity to coins the size of a dime or penny. I'm interested in the S-12, WOT, SEF 10x12 or 12x15, Excelerator 12.5" or 14". The only solid information that I have been able to dig up for the 12x15 in it's "official" field test is that it is past the point of deminishing returns for sensitivity on smaller coins and so gets less depth on those than the 10x12. But, that was tested on the Explorer so others might feel different.

Bottom line is I need something to work the very clean large sites I have were coins are easily 9" or deeper. The WOT and 12x15 are pretty close in weight and the heaviest, and I suspect the 14" Excelerator is close to them in that respect. If say the S-12, 10x12, or 12.5" Excelerator are just as deep or at least very close in depth to the bigger coils (like say within half an inch or less) I'd be willing to settle for one of those because they are so much lighter, even some being lighter than the 10" Tornado on the GT.

All I need is a little input on which people thought was the deepest compared to some other and what the depth difference seemed to be to you. If you're uncomfortable at making such claims in public then shoot me a PM. I want to pick up a larger coil before spring hits here.

 

[arihadj]

I have the 12x15 SEF coil for my Sov Elite which I love, I would say its slightly more sensitive than my standard Tornado coil and its about as big as I would want to carry. Only down sides are, needs a clean site otherwise detector will be more prone to nulling and pinpointing is more tricky. Link below is a review I have seen.

http://video.minivideos.co.uk/ja/sefcoils.pdf

 

[Critterhunter]

Thanks for the input. Yea, I read that review a while back. That's were they say the 10x12 got 6" and the 12x15 only 5.5" on a cut quarter penny. Come to think of it both those depths stink, so I'm guessing a cut quarter penny is something pretty tiny? If that's the case then of course the 12x15 would get a little less depth, and who cares. Somebody clue me in on how big one of those coins is because I'm not familiar with most of these foreign coins.

EDIT: Just googled a picture of one. No wonder they are only getting that depth on that thing. Now I guess I'll have to believe Kared about the 12x15 being deeper than the 10x12 on coins unless somebody can argue otherwise.

 

[kered]

Ive sold my 10x12, that should tell you something, left with 15x12 and 18x15, for smaller i have the 11"(although i'm talking etrac here) if needed

The cut quarter is in the middle

 

[Critterhunter]

Very good info, thanks. Did you think the 10x12 was any deeper than the 10" Tornado, or how much deeper was the 12x15 than the 10x12 to you? I've got a line on a 10x12 and I'm ready to bite but now you've got me wondering if I should go to the 12x15 or some other larger coil. Thanks for making me have serious doubts...

 

[Critterhunter]

This is a re-post from this thread thread talking about the merits of the 12x15 versus the 10x12...

http://www.findmall.com/read.php?21,1151875

Sorry for that but it seems more fitting information here...

Sound theory and good point! If it wasn't for all the above latest messages I might have just bought a used 10x12 in a PM that somebody offered at a decent price. Now I'm going to go back to the "Coil Stats & Opinions" thread (or whatever it was called) several weeks back and look over the weights I listed for the various coils. That's about the only thing that can draw me back to the 10x12 now, because I'm starting to think the 12x15 is going to be the same depth on pennies/dimes and probably deeper on larger coins.

I don't care about how heavy it is since I plan to just use it for special deep target sites. Only advantage about say the S-12 or maybe the 10x12 in size and weight would be I might be able to get away with making them my every day coil instead of the 10", since I think they are both lighter. I've read of several guys who started with a stock 8" coil on a Sovereign and opted to go to the S-12 instead of the 10". If you think about it, that makes perfect sense since it's lighter than the 10 and you'd probably see more difference going from an 8 to a 12 than you would from an 8 to a 10. For the same logic it might be better to go from my 10" to the 12x15 instead of sort'a duplicating the 10 with the 10x12.

Heres a link to that thread

http://www.findmall.com/read.php?21,1120643

Heres all the coil weights listed in ounces, from lightest to heaviest, along with prices. Note that a * means somebody actualy weighed it. The Kellyco coils (Excelerators/SEFs) were weighed for me by a Kellyco sales person, so consider that if you see the listed weight on their site is higher, like in the case of the 14. Which is right?

Sunray S-5 (5.5) 16* $189 (free shipping)
Excelerator 5 (Size?) $119 (plus shipping)
Sunray 12.5 22.7* $219 (free shipping)
Excelerator 12.5 23.2* $199 (plus shipping)
SEF 10X12 24.32* $169 (plus shipping)
Tornado 10 25.23*
Excelerator 14 26.4* $209 (plus shipping) Listed weight is 30.08. Which is right?
SEF 12x15 29.76* $189 (plus shipping)
BBS 10 29.9*
WOT 15 32 $228 (shipping?)

Obviously the WOT, BBS 10" and 12x15 coils are really hefty, so consider that if you don't want to be swinging all that weight. After using Whites the weight of the shaft/coil even with the control box hipmounted is still more of a work out on my shoulder than the Whites after hunting 6 or 7 hours. It's good to know that several larger coil size options exist for it at a lessor weight. I can see why some like to use the S-12 all the time when you consider it's the lightest of all the larger coils, the Excelerator being a close second. I sure would love to see a head to head comparison of these two coils, along with the 14" and 10x12. I'll tell you what, somebody donate them all to me and I promise to do a complete comparison of all of them.

EDIT: Just found a coil weight for the 10x12 on the Explorer/Etrac version from a field test and it was 22.8575 ounces, so the above one at 24.32 might be in error unless the windings are that much different between the FBS and BBS coils of that size.

 

[Critterhunter]

Also, the 12x15 would be sort'a a cross between an S-12 being 12" and a WOT being 15" for the two 12x15 dimensions if you think about it.

 

[kered]

The 10x12 is deeper than the 10" on the explorer(not used the 10" on the etrac as it came with the 11"), previous to the explorer, on the sovereign i went from the 10" to the Wot 15" then 15x12. In my opinion the depth gain is more due to less noise/falsing at the same sensibility setting therefore you can turn it up a bit and hence gain depth. Maybe its just me but what i have seen and also read the oval, elliptical or butterfly shape DD coils seems to run quieter than the round coils at the same settings, on other makes too, whites Eclipse, F75 fishbone, the ovals on the XP.

 

[Critterhunter]

Yea, ovals are said to lower noise, but depth should also be better just by virtue of the larger coil diameter....to a point. Larger coil size losing sensitivity to smaller targets is more of a problem with concentrics and not double Ds. 11 or 12" coil diameter is probably pushing it with a concentric for small coins.

I've got a hardly used 12x15 on the way thanks to what you've said and a few other things I've read. At first I was thrown off by the field test saying it got half an inch less depth than the 10x12 on one coin but only just realized just how small a cut quarter penny is. That explains that. I was still sort'a up in the air and leaning towards the 10x12 prior to this but then thought since I already have a 10" round I don't want something too similar like a 10x12. Same reason why it makes more sense for a guy with an 8" coil to buy the S-12 instead of the 10", 8 and 10 being too similar.

Another thing to consider is how these SEF coils are shaped. It appears from the pictures that they have more width across the entire coil length because they are sort'a rectangular in shape. If you think about it a 12" round coil is only 12" at the very center and gets smaller from there real fast, while these SEFs kind'a hold their distance apart from top to bottom of the coil, so to me that means they are really larger coils over more of their surface area, but I might be wrong with this way of thinking about it.

I've never heard a good explaination of why ovals seem to have better seperation. I'm going to guess that the more narrow width squeezes the width of the signal, yet the longer length from tip to toe gives them the depth of a coil in that larger diameter. Meaning seperation of a 12" with the depth of a 15" in this case. What are your thoughts on that?

I plan to do some testing of the 10" versus the 12x15 and will post a thread down the road on that. At 29 ounces it's still lighter than the old 10" BBS coil and about 3 ounces lighter than the WOT. It's about 4 ounces heavier than the 10" Tornado, but I've already dropped that much weight and more with my custom light shaft to make up for that. When I'm done the machine will be much lighter overall with the 12x15 than the 10" on a stock machine. It's not going to matter if the weight of this coil allows me to only hunt comfortably for a few hours at a time. I wanted it for some deep coin/light trash areas I hunt and I'm willing to only use it for those special occasions if need be. I'll just bring a small coil along and throw that on when I get worn out.

What's your opinion on the depth of the WOT versus the 12x15 and any other things one is better over the other at. You may have covered this in the past so I'll probably do a search through some old threads as well. Thanks again for all the input.

 

[kered]

To put numbers on things i would say between 1" and 3" depending on the location, the main thing i found was that the smaller items like ear ring backings, press studs and the like size wise were loud and clear at the greater depths than with the Wot .Pinpointing is also easier as the lugs are in the centre and the sweet point is right there, if you use the backward wiggle, its in the front V where the two halves come together.

Just as a thought, with you making your own shaft, if you make provision to set the box clip just a tad further back than normal it will compensate for the extra weight of the SEF coil, it makes a hell of a difference on the excalibur having the electronics slightly behind the elbow.

 

[Critterhunter]

1 to 3" difference between which coils, WOT and 12x15?

Very good info, thanks. I really like the tip about moving the box further back. Never really thought about that. I have the box normaly mounted to where it's face plate is flush with the end of the shaft, but I can see why moving it back even further would make for less stress on the arm. Normaly I have my arm all the way down into the cup to where my elbow is just inside it. Doing that and also adjusting the hand grip so that with your arm and wrist perfectly straight your palm sits flat against the grip without having to bend your wrist any. I've seen people have their machines adjusted to where either the arm cup is further down the arm than it should, or their wrist is bent to adjust the length to the grip, or with both problems. That makes for a sore arm and getting tired faster.

Using your suggestion of moving the box back even further on the shaft would leverage the weight of the coil at the other end of the shaft better. Sort'a like grabbing a pole dead center giving you more ease at twirling it in your hand than it would if you were holding it closer to one end or the other. Thanks for pointing that out. Never occured to me. If I'm thinking right you wouldn't want to move the arm cup further back, because now you're making the machine longer and chasing your tail by moving the box back? Instead, the proper thing to do would be to just slide the mounting clip for the box back further inside the arm cup mounting bracket so only the box is being moved back. Am I thinking about this the right way here or would there be any advantage to moving the cup back further too? Then again, a friend of mine hunts with his arm cup between the elbow and shoulder. Anybody do that and think it's even less stressful?

I've been digging through some older threads on the 15x12 and finding a lot of good opinions on it. Mainly, besides you I've read several people say that they also thought it was deeper than the WOT, had better seperation, pinpointed better, and was more stabil allowing them to run sensitivity higher. One guy even had the 14" Excelerator, S-12, WOT, 10x12, and I think one or two others and thought the 15x12 was the best and deepest coil he's ever used on the Sovereign. I mostly had disregarded and skimmed over any remarks about this coil before when I was reading any and all threads on larger coils because I had already formed an opinion on it based on that quarter penny testing I refered to above.

After reading your support for this coil having used the WOT and 10x12, along with further digging, I started to question that field test. That's when I realized just how small a quarter penny is. I would suspect any smaller coil to get better depth on something that tiny. Since I'm interested in penny/dime targets and bigger I'm very confident now that what others are saying about this coil being the deepest to be true. I could see the better seperation and pinpointing over the WOT but had my doubts if it was going to beat the WOT in depth. After further digging I'm very confident now.

While I've got you here, since I think you said your a beach hunter, have you ever heard of people sanding down the bottom of these coils to drop a lot of weight? I could have swore I saw a guy in the beach forum say he had his 12x15 down to 16 ounces by doing that but I can't find the thread now. I would assume that so long as the windings are near the top of the coil and nothing else is near the bottom that might very well be possible.

I'm planning on digging up a bunch of quotes from older threads on this coil versus others and will condense them down to post in this thread. Along with Kared that information really helped me firm up my decision.

 

[Critterhunter]

By the way, the theory behind moving the box back might also prove a good reason to keep your coil cable windings as up near the box end as possible as well...more weight at that box end to help counter the coil at the other.

 

[Critterhunter]

Hey Kared, one more thing. I think I read somewhere back where you said the SEF 15x12 was a bit heavier than the WOT? If that wasn't you then somebody else was saying that. According to what I've dug up in the above chart the WOT should be about 2 to 3 ounces heavier than the 15x12 and the old 10" BBS coil is also a bit heavier as well. Did you ever weigh the WOT & SEF to be sure? Of course weights my differ on the FBS and BBS versions.

I did read somewhere where somebody was weighing these coils with and without the coil cable and I think they said the 10" Tornado was 17 ounces and the 12x15 was down to like 22 ounces. Crunching the numbers that tells me the entire coil cable averages about 8 ounces in weight, which gives me more motivation to shorten my cables. I'm guessing I might be able to cut about 3 to 4 ounces of some of my coils. That could put the 15x12 at about the eight of the 10" Tornado coil with stock cable length. I know...more outter mass away from the shaft is where a lot of the weight is felt but just the same. I've already dropped more than the weight of the SEF coil in my lighter detector shaft/grip and have plans to drop more with other mods. If all goes well with a few things I'm doing I might very well drop about a pound to a pound and a half off what a stock GT weighs....maybe even more as things add up.

I don't find this machine heavy at all with the 10" for a normal hunt, but on those days I'm out 8 or 9 hours climbing up and down ravines and valleys in the woods it sure feels like a pig compared to a Whites. Hoping to change that. I know hip mounting helps a lot but I prefer not to do that if I can drop enough weight.

 

[plugger]

And, reversing the control box will also provide more protection for the knobs and switches. With the box behind you, it is all too easy to "back" into something and damage the controls.

Plugger

 

[kered]

I did that with the Excalibur on your rod, a lot less pull on the headphone cable and the pinpoint switch is closer at hand too

@CH personally i wouldn't dream of sanding the coil down as you can't tell how close the windings are, although you could take off the cover and spray with bed liner to save a few grams

I still have a Wot 15" on the xs2apro(sold the sef with the Elite and can't afford another sef to be collecting cobwebs) it weighs 29.2oz without cover, the sef 15x12(etrac) weighs 26.85oz without cover, (maybe it has a shorter cable than the sov version) the SEF cover weighs 3.65oz, can't weigh the Wot cover as i don't have one, Just went and weighed them this minute, when i take the 18x15 of the etrac I'll weigh that too for your table.

Looking at you other weight table it just goes to show that there is not that much difference to the stock tornado and lighter than the old BBS, so much for the critics that say its far too heavy(wimps )

PS its kered not kared (derek writen in reverse)

 

[Tony]

I'm running the Sovereign GT with the 15" WOT and Shaun's Amp.

I found the 15" x 12" SEF coil (sold it a few months ago) very unstable with the Amp, however, the WOT coil seems to enjoy working with the Amp.

I did extensive tests with the stock 10" coil and 15x12 SEF coil.......I really couldn't see any measurable depth difference between these 2 coils. The WOT coil is about 10% deeper than the stock but I've purchased it for coverage mainly.

The bottom line is to use what works for you in your hunting environment and as we all know this will be different for different people and their locations.

Many detector designers will acknowledge that coils in the range of about 10" to 11" are an optimum size for COIN and RING sized targets.

The best thing any of us can do is to satisfy ourselves....ourselves. Test "X" and reviewer "Y" just won't cut it for me personally.

Good luck guys with your GT's.........they are good aren't they !

Tony.

 

[Critterhunter]

And, reversing the control box will also provide more protection for the knobs and switches. With the box behind you, it is all too easy to "back" into something and damage the controls.

Plugger

Good idea. Unfortunately when I wired my remote pinpoint switch through the shaft I didn't leave any extra length as I cut it just long enough to route for the way I normaly have the box mounted. I won't even be able to slide the box back further than normal without re-wiring that, or the easy way would be to plug in a stereo cord extension to the GT and plug. I think I'll just keep it as normal and if down the road I feel I need a hair more less stress on my arm I'll re-wire it. Like you said, that would be a great way to protect the switches and, like Kered said, it would also put less stress on the coil connector at the box. Very good ideas there.

 

[Critterhunter]

I did that with the Excalibur on your rod, a lot less pull on the headphone cable and the pinpoint switch is closer at hand too

@CH personally i wouldn't dream of sanding the coil down as you can't tell how close the windings are, although you could take off the cover and spray with bed liner to save a few grams

I still have a Wot 15" on the xs2apro(sold the sef with the Elite and can't afford another sef to be collecting cobwebs) it weighs 29.2oz without cover, the sef 15x12(etrac) weighs 26.85oz without cover, (maybe it has a shorter cable than the sov version) the SEF cover weighs 3.65oz, can't weigh the Wot cover as i don't have one, Just went and weighed them this minute, when i take the 18x15 of the etrac I'll weigh that too for your table.

Looking at you other weight table it just goes to show that there is not that much difference to the stock tornado and lighter than the old BBS, so much for the critics that say its far too heavy(wimps )

PS its kered not kared (derek writen in reverse)

Thanks for that info. Yea, I wouldn't think of sanding it down either unless I can find somebody who's already done it on the same coil. I'm going to see if I can dig that message up in the beach forum and will post it if I can find the thing.

I'm suprised the coil cover weighs that much...3.65oz. Now that's going to make me re-think using one. I never did use a cover on the 9.5" on my Whites. Got sick of cleaning it before every hunt. A friend never uses a cover on his 9.5" and he's beat that machine to death over many years of intense hunting. I would figure by the time you wear out a coil years down the road you've probably got your money's worth out of it anyway. I've found that a cover doesn't really prevent scratches because water/dirt/sand/grit trapped in there will move around and put some scratches on the bottom of the coil, though I'm sure it helps prevent deep scratches. I just wonder if these SEF coils or even the 10" Minelab can stand up to a lot of use without a cover? Any thoughts on that? I would guess it wouldn't be as important to use one on land compared to hunting over sand on the beach all the time? After reading about those weights I'm tempted to keep the one off my 10" as well.

Your weights comparing the SEF without a cover and the weight of the cover match up for the most part with the weight in the chart above for the unit with it's cover on. 26.85oz for the 15x12 without the cover is just about an ounce heavier than the stock 10" Tornado with cover. More good news. Now I just have to find out if that coil will wear out fast without the cover on. Anybody use the 10" or an SEF without a cover and had no wear problems?

Sorry about spelling your name wrong. That's my ADD kicking in, and I was never a very good speller.

 

[Critterhunter]

I'm running the Sovereign GT with the 15" WOT and Shaun's Amp.

I found the 15" x 12" SEF coil (sold it a few months ago) very unstable with the Amp, however, the WOT coil seems to enjoy working with the Amp.

I did extensive tests with the stock 10" coil and 15x12 SEF coil.......I really couldn't see any measurable depth difference between these 2 coils. The WOT coil is about 10% deeper than the stock but I've purchased it for coverage mainly.

The bottom line is to use what works for you in your hunting environment and as we all know this will be different for different people and their locations.

Many detector designers will acknowledge that coils in the range of about 10" to 11" are an optimum size for COIN and RING sized targets.

The best thing any of us can do is to satisfy ourselves....ourselves. Test "X" and reviewer "Y" just won't cut it for me personally.

Good luck guys with your GT's.........they are good aren't they !

Tony.

Yes, I've read a few people say they thought the WOT was deeper than the 15x12 but I'd say the vast majority thought the SEF was deeper, more sensitive to small targets, pinpoints and seperates better, and was more stabil allowing higher sensitivity settings. Like you said, though, variables such as ground conditions could favor one over the over for people. I know testing isn't the final say but it at least gives people a baseline of what potential certain coils might have. I've heard for years that somewhere in the 10 to 12" range was about the maximum size while still keeping sensitivity to coin sized targets, but most of where that old rule of thumb came from was back in the day when concentrics were about the only coils available for machines. From what research I've done on the subject many say double D designs can get a bit larger than that and still retain good small target sensitivity with increased depth, but again that's a general rule of thumb too.

 

[Critterhunter]

Just weighed the 10" Tornado's coil cover and it's 2.5 ounces. I'm kind'a shocked these things weigh that much. If you do the math without the coil cover it's at 22.73, about the exact weight of the 12" Sunray S-12. I don't know if those coils even use a cover or if that weight was without one. If anybody has used any Minelab coils or the SEFs without a coil cover for a long time without any problems I'd like to hear about it. That epoxy looks fairly brittle on the bottom of the coil. I've read in the beach forum a lot of guys take of the coil cover and then put on spray on bedliner to drop some weight and still protect the coil. Do you guys feel you'd have to do this if you weren't going to use the coil cover?