6" vs stock vs 17" coils

[KinTN]

Maybe I'm missing something, but it seems to me that if you have several targets under any of those coils in a sweep, the CTX will tell you about them, displaying them in Target/Pinpoint Trace (assuming all other CTX settings are the same for each coil) as they should be. You'd have to sweep the 17"er slower than the others due to the greater volume it is processing, but slow your sweep down enough and the 17" screen should look just like the 6"/stock coil screen (with perhaps more targets due to a deeper look).

Yes, when there's lots of say nails in the ground, there's more of them under the 17" proportionally, but I've never read anyone say that those nails will overwhelm the CTX and miss a good target. Actually it's just the opposite, the boards are full of tests of coins actually touching rusty nails in various orientations in everything from loam to sand and the CTX sees/displays both targets.

So is using a small coil in heavy trash just a matter of convenience so that a person's hunting style doesn't need to be altered (or the brain taxed too much from more targets with a 17"er)?


((pls no one take offense. I am not thinking of anyone specifically. just pointing out what seems to be a logic fart here))

 

[Jason in Enid]

Your logic is flawed and incorrect.

 

[KinTN]

I'm sorry I took so much of your time, great master. And even sorrier that you felt the need to spend so much time replying.

 

[sube]

The thing about the 6 inch coil is it well see between the nails and find the coin where as the stock coil well have the nails and coin under it at the same time . Put it this way the stock coil is seeing 8 gallons of dirt where as the 6 inch is seeing a gallon and a half , that means the stock coil is seeing more mineralization plus the targets and the 6 is seeing less mineralization and the target.
The more nails and mineralization the machine sees the less accurate the vid .
Take the 17 inch coil for example it's I think 13 inches wide with a nail every 6 inches it's seeing 2 nails where the 6 inch is seeing none that's why you want a smaller coil in target rich areas
Now if there are 2 nails under the coil with a coin by the nail the 17 will miss this coin because it is looking at the nails and coin at the same time where as the 6 inch coil well be able to separate the nail from the coin because the nail well not be under the coil at the same time as the coin and if it sees bought at once the id well be better than seeing several nails and coin at the same time .
The ctx well see those targets with the 17 inch coil with target trace but lots of those targets well not give you and audio dig me signal it well be more garbled than the 6 or stock coil and some may not give any audio being correlated with iron .sube

 

[GKMan]

Don't mind Jason.. I believe he has a problem with his sensitivity set in manual mode a bit too low...

Subes response sounds good to me.

 

[ChicagoJohn]

My friend got 17 inch coil but return for money back! Too big and too heavy! Not good for very high trash in Chicago Park! Even 11 inch coil is not easy! Metal all over park! I think that 17 inch would be great for farm field to find old coins in wild open field!

 

[KinTN]

Yeah GKM, youre right. People that parrot conventional wisdom without any thought sometimes get to me. Gotta rise above that. I forget that some folks' stuff don't stink.

sube, Thank You for your reply. I agree with everything you say, but when testing my 17" in an infested area, I still see the good targets show up in the Trace if I sweep long/slow enough. I get that theres exponentially more volume and thus more mineralization and trash to handle, but my growing belief is that the CTX processor can handle it. Especially in Pinpoint Trace hunting (all metal) where the response will build up with successive sweeps. That's wheres its seen the easiest.

I have been testing a 20yr old unhunted school; first with the stock then hunting the same ground with the 17'. It is in the top 4 trashiest sites I have ever hunted. Infested is a better word for it. Like a dozen+ pieces of trash under the stock coil at all times. Found a lot of clad per sq foot with the stock, then rehunted the same patch with the 17 the next day and didn't find much more. Most of day 2 was probably stuff I had gotten too lazy to dig later in the day 1 hunt (like can slaw around a dime). That got me to thinking about the physics/math of the thing, which led to my question.

I don't have a 6" coil, but being the person I am, would buy one in a heartbeat if I could convince myself that it will do what conventional wisdom says it will do. Right now, it just seems that a powerful processor can overcome the limitations of larger coils if swung properly.

 

[filo]

I had great luck with the 17" in an open farm field where I had a lot of territory to cover in a short space of time. I don't use it in parks or other areas with a lot more targets to distinguish.

 

[sube]

I have been testing a 20yr old unhunted school; first with the stock then hunting the same ground with the 17'. It is in the top 4 trashiest sites I have ever hunted. Infested is a better word for it. Like a dozen+ pieces of trash under the stock coil at all times. Found a lot of clad per sq foot with the stock, then rehunted the same patch with the 17 the next day and didn't find much more. Most of day 2 was probably stuff I had gotten too lazy to dig later in the day 1 hunt (like can slaw around a dime). That got me to thinking about the physics/math of the thing, which led to my question.

It would be interesting if you would hunt a older site with deeper coins and see what your results would be.
I know that the ctx well display all targets on trace but not all by audio I don't have a 17 but I'm wondering if it would show deeper coins in a target rich area that are adjacent to iron I can only imagine what the screen would look like with that many targets under the coil .
This is the main reason I use a small coil. sube

 

[EbbTide]

I know what you mean filo! I tried out the 17" on the beach and was just overwhelmed with the trash signals. Yesterday I picked up a 6" coil and can't wait to try it out!
Best of Luck!

 

[KinTN]

sube, I rehunted a turn of the century burned down operahouse when I got the 17"er. I was definitely getting more depth out of it than I got from the stock coil. It was the first (and so far only) time I have ever taken a shovel onto a schoolyard (too many 9-12" targets for my wrist even tho the soil was predominately loamy). However, the site wasn't as trashy as one would expect. The grounds have been well hunted + a local college archeology dept has done their thing on the site as well. I suspect that all of those folks cleaned up most of the old trash there. Don't get me wrong- there was still plenty of trash, esp canslaw (its a school now), but not nearly as many nails as you would expect from a burned 2 story wood building. fwiw, I got ~12 Ag dimes and a silver ring from an area about the size of a baseball diamond infield. after getting only 1 Ag dime with the stock coil.


In it's glory days before the 1918 fire:

Folks, I really wasn't looking for just opinions or anecdotal evidence (tho I thoroughly enjoy the latter). I was kinda hoping that some of the former Minelabbers or beta-types might weigh in with some math/electronics/physics. I am coming to believe that the CTX processor is more capable than we are giving it credit for and its gonna take Math to dissuade me of that idea.

 

[trojdor]

I got ~12 Ag dimes and a silver ring from an area about the size of a baseball diamond infield. after getting only 1 Ag dime with the stock coil.

KinTN,
Nicely done!

mike

 

[sube]

I know the processor is good in the ctx but if you have trash above a target it well mast what is below even if it's 3 inches to the side of the target .But if it is at the same level or below all is good That's why the 6 is deadly in target rich areas you are really looking between the trash having a clear shot at the coin .
The area you hunted you said loamy soil was it black dirt if so there are a lot of coins that well be deeper here but before you hunted here there were lots of shallower coins that people found just as old as the ones you found there with the 17 .
I would hunt that with the 6 inch coil and see what turns up I have a feeling there well be mask coins there that nobody found yet .
That's a beautiful place to hunt I like it .
I would like to see a pic of the dimes and what depth you found them at .awesome hunt . sube

 

[KinTN]

Actually it took several hunts to recover all the treasure I found from that site. Its one of those places that you KNOW has held good stuff and therefore go extremely slow and do it from multiple directions. I'll probably hit it again after I go to Andy Sabich's CTX Boot Camp and try out what I learn. After the ground gets saturated of course (our dirt right now is Dry. hurts to dig with a trowel its so hard). sidenote: my hunt buddy and I found upwards of $60 in clad at that site (about 2x baseball diamonds total including school yard) at fairly shallow depths. obviously it hadn't been hunted properly in a while.

sube, I have never found any key date coins tho I have casually collected coins since I was a kid. After I clean a silver find (water and toothbrush), I stick it in a coin tube with similar dates. So theres no way I could tell which ones I have found where. iirc, they were typical silver you pull out of the ground in various stages of circulation. Yes, very rich and very deep soil. Light enough that I would LOVE to peel off a foot of it and find a few hundred old dates. I know theyre there.

Given the right geometry and sizes, I can see how a large Fe object could throw a shadow and I am not disputing that at all. But its never (ime anyway) a complete plane of Fe- theres lots of room between those trash items. That's how a 6" can get thru, if you will. I'm just saying that if anything can get thru and create a response, then any coil that can throw sufficient depth should be able to induce those same eddys. At that point, its a matter of if the detector's processor can handle all the info that's its receiving to find the good target among the trash or will it be overwhelmed by all the returning signals.


Another anecdotal story: Hunting in a pounded Oak Ridge, TN park with a Safari, I dug a merc at a very high angle that was touching(on top off) an entire aluminum can that was almost flat. Depth was just a few inches. I KNOW others have swung over it due to its location and just saw the can with their detectors. There was no mistaking the Safari silver sound tho the TID did wobble a bit. But that's just an isolated story and everyone has some of those with every machine.

 

[Digger]

I've never found a "limit" to the number of targets I can see with any sized CTX coil. Understanding them and deciphering all them (mentally) can be a challenge in some locations.

Here are a couple early posts, and an article posted on Minelab's website, regarding being able to see multiple targets simultaneously.

http://www.findmall.com/read.php?86,1710032,1711481#msg-1711481

http://www.findmall.com/read.php?86,1713736,1717131#msg-1717131

http://www.minelab.com/usa/treasure-talk/ctx-3030-target-trace-pinpoint-trace-smartfind-2-visually-identifying-multiple-targets

HH Randy

 

[KinTN]

Thanks, Randy; I'll check those out.
And thanks again sube for the PM tip.