Depth and 6" Coil

[tiftaaft]

After much deliberation between the 17" and 6" coils for my CTX, including considering just staying with the stock 11"... I decided to order the 6" coil, which should arrive in the next day or two (just in time for the weekend, and a break I the rain/sleet/snow weather we have been seeing here).

I'm sure this topic has been covered in other threads, and I have tried to read as many of them as I could find, but I wanted to reach out to other 6" users to get some feedback on tips and tricks using this coil.

I have been hunting a variety of locations... from parks, to schools, to soccer fields, to residential (soon woods and beaches - at Champ Ferguson's urging (+1) ). As with many detectorists, I cut my teeth on clad, but that all changed with the first wheatie, then even more so with the first silver coin... so my intent is to be able to use the capabilities of the CTX to find older coins that other's may have missed in areas that have no doubt been hunted many times over the years.

Here is where I need some input... I know everyone is talking about going DEEP, and how to get more depth with the CTX (including me in several posts)... and many talk about getting to 10 and 12" depths (or more). But, my current thought is that I want to get great accuracy of response down to about 6", or 7"... (and iffy signals in the 8-9" range) and with the ability to sort and poinpoint between trash and iron better.. to find the desirable targets (silver, old copper, gold jewelry, etc). So rather than choosing the 17" coil, and getting an extra 2" of depth over my 11", or boosting the manual sens up to the point that it is falsing multiple times each swing... I opted for the 6" coil to limit the amount of information being transferred at any given time to my ears, and navigate through junk targets to hear the sweet tones. And even if that means boosting the manual sens up higher than I would on the 11 or 17, at least the ground it is trying to penetrate is a smaller radius, and should create less falsing/noise.

Ok guys... how far off base am I? 6" coil users... has this been your experience?

I know I am giving up ground coverage (especially in larger open fields) but I tend to find myself working smaller patches of grass, and spending a lot of time slow swinging in those areas. Another reason I wasn't afraid of the smaller coil.
Hoping to get some good feedback, as the comments on this site are always very informational and fascinating.

I will post pics of any "keepers" once I receive the coil and give it a good test!

Thanks everyone and HH,

Tim.

 

[crk2]

Tim,
A 6" coil will be a good asset to hunting trashy areas. I use a small coil in parks where there's a lot of summer activities and pull out keepers amongst the pull tabs, can slaw and other junk. Slow and patience is key.

 

[sube]

Your pretty spot on . I love this coil it has great depth in my soil mild to medium 6 to 7 inch very good signal and to 8 inches I have dug 6 to 7 coins each year at 9 inches don't happen very often but does hit here .

Ait test well show it will hit a dime at 10 to 11 not the best signal but it's there now you will loose in the dirt some depth but not as much as you think . It's the only coil I can run at 30 manual in my soil so you can get really close to what the stock coils depth is because you can run it hotter

As far as falsing still going to happen but easier to get rid of because you have less targets under the coil at one time making it easier to separate out the good from the bad . One thing about coil speed and the ctx the more disc you use the slower the sweep speed you have to let the machine keep up with the imfo it is processing . Now with the 6 in open screen your sweep speed will not affect your detector like in a disc pattern so normal sweep speed is fine . When using the 6 inch coil or any I like to move a inch a time on a sweep on deeper targets the machine will see it 1 to 2 more times than not overlapping this close .

As you know on shallow targets the curser builds on one sweep but on deeper targets you may have to sweep it several times to get that same curser intensity that you got on one sweep . The machine is building the target and sound as you sweep it the more sweeps the more info the machine can process which gives a better vdi of said target .( IMPORTANT)

Now I really don't run any patterns (disc patterns ) I generally run open with some disc in the bottom 32 to 35 and 47 to 50 right side of screen just to get rid of some iron I still get high tone falsing at 39 to 46 on the 12 line but don't have to listen to the high toning from 47 to 50 makes it a little easier.

The reason I don't run more disc is because I can see what all the target vdi are just by looking at the screen I only have 2 sounds to hear 1000hz and 75 hz kiss my bins are set to 1000hz at 10 to 15 and 29 to 50 and all the rest are set at 75 hz so all I have to do is listen for the 1000 hz . Now if yo have fatty Indians I will open for them 20 to 24 at a 1000hz .

I still think if most of the coins are at 4 to 7 inches in your area that the 6 will find more than the other coils it may take more time to detect but your doing it in one pass .Now there are coins deeper but if your coins are coming in at 4 to 7 on average there are far more still in that range mask or partial masked that the 6 will find that the other coils won't . With that said I would say 95 percent of the coins left will be in this depth range and 5 percent will be deeper so what do you won't to find the 95 percent or the 5 percent .

This is only my opinion but it works for me still love this coil sube

 

[Ben Town]

I just recently got a 17" and 6" coils for my CTX.
As it seems to still be winter here in the Midwest I have only been able to use them in the detector garden.
I have different silver coins and clad and trash at 6-7 " and the 6" coil struggles at best.
It will hit a few and miss a few.
I have changed settings and modes and sensitivity and nothing makes a real big difference .
I have some trashy spots that I want to try it in and I'm sure it will pull out some stuff.
I guess what Im saying is don't expect a lot of depth. I was a bit disappointed but like I say I have a real trashy area to try
Before the final verdict is in.
Buy the way the 17" is going to be killer " with a harness "
BT

 

[sube]

Ben Town test gardens are just that you will have to wait years for the soil to compact back to what it was before you dug the holes .

The loose soil is what is causing the depth loss even with my stock coil I have a hard time getting pass 8 inches on a dime in my test garden .so I think your going to be surprised when you start digging deeper in the wild .sube

 

[IDXMonster]

Tim...you seem to be spot on with your intentions and expectations. Different soil conditions will dictate what can be expected from the coil of choice,along with GAIN and Sensitivity settings. Sube has MUCH experience with this little coil and I intend to use it ALOT this season because of what you're thinking and his past posting on its usage...MOST of the coins are simply HIDING,but not necessarily out of reach of a small coil,especially with the settings properly adjusted. I think of how many old coins I've found really deep as opposed to the 5-8" coins and it's no contest,MOST have been 5-8". This is MY own experience,and I don't know why,unless you have miles and miles of old parks with loose black dirt,that it wouldn't be similar in your area. It is so much easier to use and differentiate what's under the coil it's ridiculous.

 

[tiftaaft]

Thanks for the comments everyone! I am glad to know I'm not out in left field on this (unless of course there are some nice silver targets in left field .

@CRK2 - I have to remind myself to slow down on occasion, and I'm learning patience... I think this coil should help me with both.

@Ben Town - I had some of the same experiences with my test garden, but I can vouch for Sube's comments, "in the wild" is a whole different ballgame.

@Sube - What a great and thoughtful response chock full of good information... THANK YOU! I have been running a moderate disc pattern, somewhere between Stock Coin and Andy S... but what you said makes sense, especially if I am trying to hear those nice conductive targets next to iron and such... I will definitely open the pattern up a bit more and let the machine talk to me. Also good comments on building the target in target trace. Thinking back at previous hunts, I was seeing that the machine needed to work a little bit (multiple passes) to build those deeper targets on the screen, but it didn't dawn on me that I needed to give the machine a chance to properly id the target with multiple passes... I was just taking multiple passes so I could build the target profile in my head (and I have found that the CTX is usually smarter than I am)... good stuff there! I will be re-reading your post over and over the next several days to make it stick in my head when I'm out hunting. So reading through your current settings on a mostly open pattern... it looks like you are running combined and letting the nickels and coins scream out. two follow up questions... where do you have your ferrous bin set? and since you are low toning the foil and pulltab ranges, you are also low toning some gold... have you had much luck with gold jewelry coming through at the 29+ in your hunts?

@IDXMoster - Also very informative post... thank you! Getting some verification on my idea that I don't need to GO DEEEEEEP to uncover the missed targets gives me some confidence heading out to my hunting grounds. I do have a question on your comment about gain. This has been a setting I haven't moved around much... what is your thought on the gain setting? I have had it pegged pretty high I believe (I'll have to check my settings again)... I was thinking that a higher gain would make the deeper targets stand out more, but maybe I only want the medium depth targets to stand out more... (which would eliminate some of those sweet sounding bent rusty nails at 9+inches). I'm with you... I want to find the hidden coins...not the ones that somehow found a way to since a foot or more (I would guess that theory might change on the beach, but that is another thread for another time).

Again, thank you all for the time you took to respond!

Tim.

 

[Ben Town]

Sube I'm going to trust your experience and knowledge.
I'll be out as soon as the weather cooperates, we got 4" of snow today, ugggg.
BT

 

[sube]

I do find gold once in a while mostly between 1 and 15 but generally I hunt sites that are not very gold worthy but if I wanted the gold I would open from 1 to 15 high tone . Most of the time I get a single low tone it stands out compared to a double or trashy signal I will look at the screen and if solid one tone will investigate . My ferrous line is set at 34 I have 32 to 35 disc out targets that are 32 to 35 are going to low tone anyway disc or no disc targets from 31 to 1 are going to high tone so if you get a 31.45 it well high tone but if your fe line is set at 25 you will hear only a low tone.

Now any gold that reads 29 or higher is going to be some big stuff class ring and so on and no I have not hit any yet but that's just my sites .As for sweet sounding bent nails look at the bottom curser it will tell you .

My gain is set at 30 I want to hear it all I never could figure out why people would run less just to hear less ?

Ben Town give that 6 a good workout it will show you what your missing and I still have a foot and a half of snow CABINE FEVER and waiting . sube

 

[flysar]

sube -
I don't use my 6" coil much because I find there are other machines I've used from Makro, Nokta, and Tesoro that seem to separate better if I find my stock coil is nulling (rejected iron) constantly. My soil is highly mineralized, A+3 sensitivity is often as low as 8, sometimes as high as 18-19. Am I selling the 6" short?

 

[IDXMonster]

Tim...while I am NO authority on any metal detector,my thought on GAIN is bordering on what you said about those sweet sweet nails! I don't like pegging GAIN because of iron falsing. It'll still false,don't get me wrong,but it'll be more in the background and not as pronounced as a true coin hit. I think sometimes we over-analyze because we are HOPING there are more coins left in our sites,when in reality, we just don't know. This leads us to investigate every little tiny peep. Watch this video and listen to how OBVIOUS these targets are. Granted,he's using an EX2 looking for low conductors,but the point is,even in a lot of iron,the good targets will be found by just trusting the machine,whatever it is,to find them. Not finding targets? Move on! Just my take on https://youtu.be/Gs9y5JQAvHE

 

[Daniel Tn]

I didn't really like the 6 inch coil. In my soil it didn't do so great in depth or separating; not as good as other machines with 5 inch coils attached to them. So I didn't really see any need in keeping mine. I realize that different soil conditions will make it perk up though. I just happened to find that another machine I have with a smaller coil went deeper and worked better in thick iron, so that was a win/win. Rumorville is that another CTX coil may be coming very soon but I haven't been able to squeak out any details on it.

 

[sube]

sube -
I don't use my 6" coil much because I find there are other machines I've used from Makro, Nokta, and Tesoro that seem to separate better if I find my stock coil is nulling (rejected iron) constantly. My soil is highly mineralized, A+3 sensitivity is often as low as 8, sometimes as high as 18-19. Am I selling the 6" short?

Well I don't envy your ground glad I don't hunt in bad dirt .

I don't have much experience in running in bad dirt but minelab says go to ground coin I have run gb in some areas that my sensitivity has gone down to 12 with ground coin I have noticed if running in gb that it takes longer more passes to build targets ground coin tends to place all iron hard in the right corner of the screen . If you get a coin with iron it will peg it right in the corner now with muti passes in pinpoint sizing that little arc trace coming off the side of the curser that stuck hard in the corner will come out and leave a path to where it hits on the screen. You have to watch that lower curser to see if there is something else with the iron if you don't you will never know because you won't get a high tone from this . Unlike ferrous coin that trys to put it on the 12 line which is superior in iron with coin mixed with iron .

Bad dirt is bad dirt have you tried pinpoint sizing all metal and what are your depths 6 inch coil to stock because the 6 can be run hotter than the stock but am wondering if your trying to punch threw that much mineralization using more sence that it actually is limiting your depth . You know just as headlights in the fog

All I can say is you have your dirt and can do several test that I can't if you did all the test and still can't get depth then I would say the ctx is not for bad dirt .

I'm sure there are others on here that have bad dirt and can answer your ? better than I can .

Anybody else have bad dirt that can answer his ? sube

 

[tiftaaft]

sube -
I don't use my 6" coil much because I find there are other machines I've used from Makro, Nokta, and Tesoro that seem to separate better if I find my stock coil is nulling (rejected iron) constantly. My soil is highly mineralized, A+3 sensitivity is often as low as 8, sometimes as high as 18-19. Am I selling the 6" short?

Well I don't envy your ground glad I don't hunt in bad dirt .

Sadly, I live just down the road from Flysar.... I think "bad dirt" has been on of my challenges as well. I have been running in ground/coin some, usually with an open screen. My disc'd pattern is ferrous coin. I get the same range of auto sens readings and range as flysar... which is why I have been trying to find a medium manual setting to boost the machines ability to get past the surface and mineralization, but not too high that it starts barking at me (I have been using 19-21 manual sens). I read a post on another forum that talks about the comparison between auto and manual as far as air tests, and it was very interesting... I will see if I can dig up the table and repost here.

As I said earlier, I don't necessarily want to push the machine down to the 9"+ range, I just want to find a nice stable 5-7" setup in my ground conditions. I was hoping that the 6" coil would help me with that... One thing I am trying is running the seawater setting on to see if that helps with the ground mineralization... since it was designed for just that at beaches. In my few tests, it did seem to stabilize the tones a bit, and quiet down some of the falsing...

 

[tiftaaft]

This is copied from "the other forum" and I want to give credit to the user for this post... his user id is Jackalope.. Anyway, this was really a eye opener for me... how the auto sens vs. manual sens overlaps... This is why I decided to stare trying a medium manual sens... to get a little more depth than the auto setting, and it doesn't move around based on the ground conditions like auto does. (I may be hurting myself with this approach, so please challenge my thought process...)

[size=small]There are many different pattern and tonal mode combinations. Really depends on the desire targets. Gold rings are often low conductors - but so is foil. Nickels are in the same zone as some bottle caps and pull-tabs.

But, generally, you use an open screen (or nearly so) as Pattern1. The more disc the less sensitivity to low conductors - the effect with even a little disc can be dramatic (meaning - with disc the detector can become gold dead. The CTX is already struggling with low conductors, lose more sensitivity and woman's rings are gone. It's main transmit power is at 3.125kHz, which isn't going to excite low conductors to respond much, i.e., drive eddies. That's great in reducing reaction from iron, but not good with jewelry. The harmonic at 25kHz has much less xmit power. Those are the two xmit freqs the CTX uses - so small gold will be missed if it is a bit deeper).

By the way, noise channel11 will raise the xmit freq by about 10% (and channel01 lowers it by 10%. Channel06 is uncorrected). On the one hand it may help to have Ch11 set to improve low conductor reaction, might help with jewelry - but on the other, the offset is meant to avoid interfering freqs from the surroundings (may not be an issue in the woods, ghost towns, or farmlands, or in the morning before people start using EMI producing machines). The risk of not using auto noise cancel (and setting it manually) is that the signal-to-noise ratio can drop and radio interference will cause erratic operations. Otherwise, it may be worth a try (some people think so anyway - but it is a very minor freq shift. Gold detectors, where gold is a very weak conductor use > 40kHz freq, even one at 71kHz (GB2) and 82kHz Gemini3). But most general detectors use 7.2 -19kHz range. So, a 2.78kHz increase should have minimal effect - but worth investigating).

Pattern2 is normally selected to include more disc to eliminate nails and/or trash items expected at the hunting site. The heavy disc patterns you see are for cherry picking high conductors. The more restricted the open areas become the more likely you'll be walking past deeper high conductors (which tend to be below (higher FE values) the expected 12Fe line). Those disc'd areas produce no audio, so use it judicially. For those looking for low conductors too (like rings & jewelry) the best pattern will need to allow trash too (open < 15Co - that's where rings hide) and also be limited in overall disc usage (to maintain detector sensitivity - though in trashy sites you have to maintain sanity too).

The tones are set for personal preference - but generally the desired target gets the high tone bin (usually narrowed around its common Fe-Co values).

Many choose two-tone ferrous (2TF). Set where everything with low Fe values (such as < 25Fe) will produce a high tone (you'll get high tones on most good targets plus trash items too).

Some parks and relic hunting involves tones of nails strewn about. 2TF in nails can have problems. The iron can cause high conductors like coins to respond with high Fe values, similar to the nail. It was found that in 2TC/4TC, or Multi-conductive (MTC), the med-high to high conductors, like coins (not nickels), will respond with a high tone where 2TF will not respond. If you use the conductive modes, any low-conductive rings should be double checked (e.g. set 4TC for high tone in the low conductive zone where thin rings hide).

Ferrous-coin mode is best used in non-mineralized soils or nail-free soils. Ferrous-coin is prone to audio nulls in nail beds and mineralized soils. Suggest using Ground-coin instead in those circumstances.

Use Auto+3 sensitivity for hunting recent drops and coins within the top 4-6". If you are serious about getting the deeper coins (6-12") and low conductors (even near the surface), switch to manual sensitivity. Generally, the CTX becomes more sensitive than Auto+3 when Manual Sensitivity > 15. Manual is quirky/sparky as it is more unstable, introducing more noise (lower sig/noise ratio), but it is much deeper. On the beach where coins are near-surface Auto+3 is fine (and quiet). If small jewelry is included at the beach, it might improve your chances using Manual. If you have the time, grid-hunt in Auto+3 and then re-search in Man+30 to pick-out anything missed.

Recall the sensitivity arrangement: left value is highest sensitivity available (out of 2 freqs used plus ground, called channels) or if in manual the left value is the sensitivity you've set. The right value is the suggested sensitivity (an average of all channels) from the detector's algorithm.

When the soil is mineralized/iron-strewn, expect the suggested sensitivity to be low (use it as your guide). The greater the difference between the manual set value (left) and suggested (right), the more likely noise will be a problem. If it is too sparky in manual, drop the manual sens value down until it is more stable.

One note on manual vs. auto choices. Iron has a permeability > 1, and will drive the magnetic lines of flux (from the coil) through it's length. With nails in a preferred horizontal resting position the coil's field will be spread wide but gain little depth. The same thing goes for magnetite layers (horizontal bars). Depth will be greatly reduced. Increasing the sensitivity has little to no effect on increasing depth in that case (may only increase unwanted response from nails, especially when wet). So, sometimes it is best to take it easy and back down the sensitivity - a more stable detector is easier to locate true audio responses from those conductive tones.

You can see the difference with sensitivity between Auto and Man from the diagram below (all things being equal)[/size]

 

[flysar]

sube, the CTX works the best in my bad soil for depth and accuracy of ID of the many detectors I've owned... until the CTX is in a heavy ferrous site and my experience is the 6" coil didn't improve the situation; I normally default to another machine.
Playing around one day, I tossed a size 6 10k gold promise ring on the grass in my yard to learn the numbers and all I got was nulling when I ran my CTX over it. I opened up the screen and heard only iron grunts. I installed the 6" coil and nothing changed. I grabbed my Tesoro Outlaw and Nokta Fors CoRe and both got the ring clearly with iron discriminated; the Nokta registered a good gold/foil ID. I dug the area and relatively shallow was misc small nails and a small gear. I figure if I don't here it I'm not going to investigate with target trace.
I run Ground-Coin or High Trash exclusively since Andy's book suggests that for high mineralization and A+3 to avoid the fog in headlight situation.
Ive owned two CTXs but I'm not nearly as well versed in the machine as you and others. I sold my first before warranty expired since I'm a water hunter too and bought a new one. I'll probably always have one in my arsenal! The
Thank you for your insight and great videos.

sube -
I don't use my 6" coil much because I find there are other machines I've used from Makro, Nokta, and Tesoro that seem to separate better if I find my stock coil is nulling (rejected iron) constantly. My soil is highly mineralized, A+3 sensitivity is often as low as 8, sometimes as high as 18-19. Am I selling the 6" short?

Well I don't envy your ground glad I don't hunt in bad dirt .

I don't have much experience in running in bad dirt but minelab says go to ground coin I have run gb in some areas that my sensitivity has gone down to 12 with ground coin I have noticed if running in gb that it takes longer more passes to build targets ground coin tends to place all iron hard in the right corner of the screen . If you get a coin with iron it will peg it right in the corner now with muti passes in pinpoint sizing that little arc trace coming off the side of the curser that stuck hard in the corner will come out and leave a path to where it hits on the screen. You have to watch that lower curser to see if there is something else with the iron if you don't you will never know because you won't get a high tone from this . Unlike ferrous coin that trys to put it on the 12 line which is superior in iron with coin mixed with iron .

Bad dirt is bad dirt have you tried pinpoint sizing all metal and what are your depths 6 inch coil to stock because the 6 can be run hotter than the stock but am wondering if your trying to punch threw that much mineralization using more sence that it actually is limiting your depth . You know just as headlights in the fog

All I can say is you have your dirt and can do several test that I can't if you did all the test and still can't get depth then I would say the ctx is not for bad dirt .

I'm sure there are others on here that have bad dirt and can answer your ? better than I can .

Anybody else have bad dirt that can answer his ? sube

 

[tiftaaft]

Now I really don't run any patterns (disc patterns ) I generally run open with some disc in the bottom 32 to 35 and 47 to 50 right side of screen just to get rid of some iron

@Sube - just re-reading your posts... so you disc out 47-50? What mode are you running? Would you be disc-ing out quarters with that setting? as well as halves and dollars?

 

[sube]

Ferrous coin I run if you run ground coin you will have to accept 47 because quarters hit here . Now in my soil halfs and dollars come in at 12.43 to 45 and quarters come in at 12.45 to 12.46 . You will have to test to see where your coins come in .

Read trojors post he has bad soil and has his methods sube

 

[IDXMonster]

To add....I've personally witnessed my Explorer throw very high numbers on MULTIPLE coins in a hole for some reason. Absolutely NEVER have a dug a good target with the HIGHEST Conductive number being reliably displayed on either CTX or EX2.(31 on EX2 or 50 on CTX)