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Digging Deep Targets...

AirmetTango

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I'm still a rookie with exactly one year of detecting under my belt, so I'm definitely still learning some of the finer points of the hobby. Lately I've been thinking more and more about detection depth, and learning when to go after a potentially deep target.

The vast majority of coins (and targets in general) I've dug are at 6" or less, and the overwhelming percentage of those are less than 4". I've dug exactly 2 coins at 8" (both with my second, recently upgraded machine), and don't think I've ever dug a coin deeper than 8". For me as a noob, those 8 inchers were "deep" - the signals were scratchy and difficult to repeat, but each did still produce high tones among some jumpiness. But since the signals weren't great, I was pleased that I persevered to grab the finds while expanding my knowledge/boundaries as a detectorist at the same time.

Those two 8" targets were in an area that I know I've hunted with my previous detector - it's entirely possible my coil was over them before, but I walked past them because I only got a trashy grunt, or no signal at all. The upgraded machine perhaps gave me a little more depth to turn those trashy old signals into diggable, but scratchy high tones.

So all this long winded intro finally leads to my questions. I understand that for any detector operating in given soil conditions, a depth is reached that causes the detector to skew target readings more and more toward the iron side. Presumably, a silver quarter at say 10" might only read as a pull tab or worse, correct? At the same time, I've heard and read from several sources some variation of "deep targets should be dug by sound, not TID". By sound, are we just talking a somewhat solid and/or reasonably repeatable signal? Are more experienced guys really digging deep, scratchy mid-tones because they know it's a good target that drifted into the pull tab or other low conductor range? Or are they only digging if it shows at least some high tone?

Sorry for the very noob question, but I've been watching several YouTube vids showing folks testing various machines on deep targets in test gardens and after hearing the tones, they're saying "Yep, I'm definitely digging that"...and I'm thinking to myself "I guess I've got a lot to learn, 'cuz that sounds like junk all day long to me..." :?:

I'd do a test garden of my own, but for the last 6-8 months, my whole yard is suddenly pounded with EMI. One of the neighbors installed an invisible dog fence, and both my detectors are now completely worthless anywhere on my property :roll:
 
You might want to get one of the several sites that have Manufacturers specific forums. Asking there might provide a more definitive answer for you machine.

Different machines can give different audio clues to the presence of deep targets. But your use of the term "scratchy" is not usually associated with the tones of good target with the detectors I have used.

Tones and experience are where it's at for the deeper stuff no matter what the machine is. With some machines and places that may 4"; with others it may be 8" or more.
 
Alot will depend on your ground and how your machine reads the minerals in it.
I have one site where it's very soft on the top layer, so the targets have sunk and start around the 7 inch mark. Some machines i've tried there have found basically nothing, and others have excelled to easily 10 Inches.
On other well used sites we have, the top 6 inch has been mostly cleaned, i very rarely find a shallow target on them.
If the ground is mineralised then the deep silver/copper can climb further up your ID scale, and tip over as such into the ground/iron zone, so scratchy half hightone/iron tone signals are common.
On many machines the point where the end of the ID scale meets the ground zone is filtered, as this is where you get a lot of falsing and iron wrap, kind of like discing out the last few ID numbers so as your machine runs smooth, but this is where the deep silver reads, so avoid any disc at the top end.
Also choose your frequency/coil size to match your target, US coins are mostly high conductors.
 
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This is where a test garden comes in handy. I know what my 10 inch silver quarter sounds like and I come upon signals very similar from time to time and I dig them because I know that sound. The other way is just to dig sketchy signals as a habit and you will learn what deep coins sound like when you find them. When I swung the at pro I learned that an iron sound with a high blip every so often could be non ferrous. With the Deus running "hot" in full tones I learned a high squeak with a bit of an iron sound should be investigated. I had such a signal a few days ago, squeaky irony sound that turned out to be a 7 inch deep Washington silver with a few nails around it. Sometimes you just have to dig iffy signals on the chance it could be a great find. I should also say that I dug the same sounding signal in a field yesterday that was part of a horseshoe 20 inches deep. Yes I knew it was not a coin as I passed 12 inches but I had to know what it was being that deep.
 
You have to be very observant

and almost talk to yourself when you are just starting out to understand the unique conditions of your area and your machine and your dug targets.

After a while your observations will become almost "intuitive".

Your success is dependent on how well you can master this ability.
 
and almost talk to yourself when you are just starting out to understand the unique conditions of your area and your machine and your dug targets.

After a while your observations will become almost "intuitive".

Your success is dependent on how well you can master this ability.

I concur completely,well said. It’s the “intuition” that can’t be taught...must be learned with experience.
 
I'm still a rookie with exactly one year of detecting under my belt, so I'm definitely still learning some of the finer points of the hobby. Lately I've been thinking more and more about detection depth, and learning when to go after a potentially deep target.

The vast majority of coins (and targets in general) I've dug are at 6" or less, and the overwhelming percentage of those are less than 4". I've dug exactly 2 coins at 8" (both with my second, recently upgraded machine), and don't think I've ever dug a coin deeper than 8". For me as a noob, those 8 inchers were "deep" - the signals were scratchy and difficult to repeat, but each did still produce high tones among some jumpiness. But since the signals weren't great, I was pleased that I persevered to grab the finds while expanding my knowledge/boundaries as a detectorist at the same time.

Those two 8" targets were in an area that I know I've hunted with my previous detector - it's entirely possible my coil was over them before, but I walked past them because I only got a trashy grunt, or no signal at all. The upgraded machine perhaps gave me a little more depth to turn those trashy old signals into diggable, but scratchy high tones.

So all this long winded intro finally leads to my questions. I understand that for any detector operating in given soil conditions, a depth is reached that causes the detector to skew target readings more and more toward the iron side. Presumably, a silver quarter at say 10" might only read as a pull tab or worse, correct? At the same time, I've heard and read from several sources some variation of "deep targets should be dug by sound, not TID". By sound, are we just talking a somewhat solid and/or reasonably repeatable signal? Are more experienced guys really digging deep, scratchy mid-tones because they know it's a good target that drifted into the pull tab or other low conductor range? Or are they only digging if it shows at least some high tone?

Sorry for the very noob question, but I've been watching several YouTube vids showing folks testing various machines on deep targets in test gardens and after hearing the tones, they're saying "Yep, I'm definitely digging that"...and I'm thinking to myself "I guess I've got a lot to learn, 'cuz that sounds like junk all day long to me..." :?:

I'd do a test garden of my own, but for the last 6-8 months, my whole yard is suddenly pounded with EMI. One of the neighbors installed an invisible dog fence, and both my detectors are now completely worthless anywhere on my property :roll:

Good post with some good questions.

Will depend on detector model used, coil size, and ground minerals.
Detectors like Etrac and CTX in mild to medium mineralized ground generally will quit detecting a nonferrous find rather that allow a deeper find be reported as ferrous. This assumes no ferrous as part of the detecting scenario of a nonferrous deeper target.
 
Great question. I am a new guy too with an ATP and have been wondering if I am missing deep targets that I pass on since they sound iffy. I've been trying to dig repeatable signals. I've dug quite a few iffy signals that sounded good swinging one way, and bad swinging at 90 degrees to only find very deep iron so far. In contrast, I have dug some coins that had iffy signals that turned out to have nails next to them. I hunt the woods, and sometimes just kicking off the leaf layer can drastically change the way a signal sounds. Sometimes better, sometimes worse.
 
Good post with some good questions.

Will depend on detector model used, coil size, and ground minerals.
Detectors like Etrac and CTX in mild to medium mineralized ground generally will quit detecting a nonferrous find rather that allow a deeper find be reported as ferrous. This assumes no ferrous as part of the detecting scenario of a nonferrous deeper target.

I have absolutely found the same to be true,at least with the CTX. The “drop off” is very steep,it goes from detecting a non-ferrous item to not detecting it at all with almost no “drop” toward the iron range. This effect is really noticeable to me in Auto sensitivity settings,as opposed to Manual sensitivity.
 
For one thing most coins are at 6 inches or less so that's what you are mostly going to dig.

When I had the AT Pro 5-6 inches deep seemed to be it's limit in the soil in my area. I can't remember digging deeper than that. I went to the Etrac and was very surprised at how deep it could go. 5-6+ inches is easy for the Etrac. It has found many coins at over 8 inches.
 
For one thing most coins are at 6 inches or less so that's what you are mostly going to dig.

When I had the AT Pro 5-6 inches deep seemed to be it's limit in the soil in my area. I can't remember digging deeper than that. I went to the Etrac and was very surprised at how deep it could go. 5-6+ inches is easy for the Etrac. It has found many coins at over 8 inches.

I've noticed the same thing switching from an AT Pro to a CTX here as well.
 
The reason it's not dropping towards the iron zone may be because that part is filtered out by the programming, it's there, you just don't hear it.
My Signum doesn't have that filtering at the top end of the scale, but it does allow you to program it in yourself gradually if you wish, and it can help you catch the deep one's but you can also dig a bit more iron, sometimes it's worth it though.

I have absolutely found the same to be true,at least with the CTX. The “drop off” is very steep,it goes from detecting a non-ferrous item to not detecting it at all with almost no “drop” toward the iron range. This effect is really noticeable to me in Auto sensitivity settings,as opposed to Manual sensitivity.
 
It takes a lot of hours and practice and experimenting to learn what the fringe targets respond like. It also requires that you pay very close attention to details of the responses to learn what it good and what is bad.

Here is a video of a target that most CTX users would walk away from but it has telltale marks that show it is very likely a good, deep target.


https://www.youtube.com/watch?v=QCcRX5QG-eQ

BTW, "deep" is subject. The soil minerals, composition, density, moisture and target orientation all play a part in how well any detector can "see" a coin. I can hit a 10 inch, flat dime but an hour down the road it might be maxed out to see it at 6.
 
The reason it's not dropping towards the iron zone may be because that part is filtered out by the programming, it's there, you just don't hear it.
My Signum doesn't have that filtering at the top end of the scale, but it does allow you to program it in yourself gradually if you wish, and it can help you catch the deep one's but you can also dig a bit more iron, sometimes it's worth it though.

Don't know for sure.
But in Fisher F75 detecfor 5 bars indicated ground, CTX and Etrac will yield nonferrous at shallower depths and report as ferrous.

And this would be with the exact same settings used in milder or medium mineralized ground where neither unit tend to give iron reading on nonferrous.

Now, deeper target that don't tonally report can be heard by threshold sometimes depending on depth. Just that op doesn't know for sure if what casing threshold to break is nonferrous or ferrous.
Did know one gent that dug a reaaaaaal deep half dime using se pro by listening threshold behavior.
 
I'd mostly agree there,
At shallow depths in bad soil, the Etrac has no problem telling you a target is there, it gets a strong signal from the coin, but the software can't cope with the ground, and iron it is.
Yet in milder soil it doesn't call a deep weak coin signal as ferrous because the software isn't overwhelmed and works as it should.
There's probably a cutoff point where when the signal strength falls below a certain level, the software kicks in and doesn't report it as ferrous.

The ground is the key, you don't get the Etrac calling a coin as ferrous at it's max depth in an air test, so ground software filtering is defo going on, but at what mineral level does it overload and stop working??

Again this is just me thinking out loud, i'm probably miles off course lol

Just an edit to add, if i run my Signum with no ground filter, it will call coins as iron at a certain depth, when i start to add ground filters, it reduces the ground effect and the coin comes back over the border into the non-ferrous side, so there's a level of ground filtering needed in mineralised soil, just how much varies, but if this setting is fixed into your detectors software, you just have to go with what it's set too, and you won't know what you ever missed because it may have sounded as iron.
Now, if we had Calabash's soil we could all but forget about this problem lol


Don't know for sure.
But in Fisher F75 detecfor 5 bars indicated ground, CTX and Etrac will yield nonferrous at shallower depths and report as ferrous.

And this would be with the exact same settings used in milder or medium mineralized ground where neither unit tend to give iron reading on nonferrous.

Now, deeper target that don't tonally report can be heard by threshold sometimes depending on depth. Just that op doesn't know for sure if what casing threshold to break is nonferrous or ferrous.
Did know one gent that dug a reaaaaaal deep half dime using se pro by listening threshold behavior.
 
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Thanks for all of the great responses, guys. I really appreciate all of the thoughts and info - gives me plenty to think about and try. The bottom line is certainly that nothing will beat just getting more swing time and experience with my machine in my area’s conditions - no real surprise there!

You might want to get one of the several sites that have Manufacturers specific forums. Asking there might provide a more definitive answer for you machine.

What?? Go to a different forum?? Blasphemy! :lol: Seriously, that’s a good thought - I’ll check some manufacturer specific spots. There’s a user group for the machine right here on FMDF, it just doesn’t get visited very often - but I’ll post there, too. Plenty of users here I can PM as well.

Different machines can give different audio clues to the presence of deep targets. But your use of the term "scratchy" is not usually associated with the tones of good target with the detectors I have used.

My inexperience might be showing with my use of terms...I called the signals for the 8” coins in my original post “scratchy” because the high tone was fainter, hard to isolate and repeat, with occasional swings giving a mid tone. Because there was some iron around, there were also quick iron pops to deal with, which to my ear makes the target sound “scratchy”. Overall, there was enough there to entice me to dig, but honestly I wouldn’t have been at all surprised if junk came out of the hole instead of silver.

Tones and experience are where it's at for the deeper stuff no matter what the machine is. With some machines and places that may 4"; with others it may be 8" or more.

No doubt experience is the key - I certainly will remember how those two 8” silvers sounded!

Alot will depend on your ground and how your machine reads the minerals in it.
.....
Also choose your frequency/coil size to match your target, US coins are mostly high conductors.

Lots of good info, thanks ghound!


This is where a test garden comes in handy. I know what my 10 inch silver quarter sounds like and I come upon signals very similar from time to time and I dig them because I know that sound. The other way is just to dig sketchy signals as a habit and you will learn what deep coins sound like when you find them. When I swung the at pro I learned that an iron sound with a high blip every so often could be non ferrous. With the Deus running "hot" in full tones I learned a high squeak with a bit of an iron sound should be investigated. I had such a signal a few days ago, squeaky irony sound that turned out to be a 7 inch deep Washington silver with a few nails around it. Sometimes you just have to dig iffy signals on the chance it could be a great find. I should also say that I dug the same sounding signal in a field yesterday that was part of a horseshoe 20 inches deep. Yes I knew it was not a coin as I passed 12 inches but I had to know what it was being that deep.

Great info, remmy, thanks! I’m learning similar for my machine. Cross referencing the depth meter/proportional audio with the “high blip” among an irony tone is what helped me get those 8” silvers from my original post - my only two “deep” coins. Since I’m still learning the machine, I’ve since chased similar sounding signals only to find trash - but the depth meter indicated 4 or 6” depth, so I should’ve known better. Unless the site is particularly trashy, I’m finding that coins aren’t “sketchy” at all at “shallow” depths with the machine.

and almost talk to yourself when you are just starting out to understand the unique conditions of your area and your machine and your dug targets.

After a while your observations will become almost "intuitive".

Your success is dependent on how well you can master this ability.

I definitely do this - I talk/think my way through a signal as I’m swinging over it to help process what the machine is trying to tell me...I’m also trying to guess what I might have before I dig!

Good post with some good questions.

Will depend on detector model used, coil size, and ground minerals.
Detectors like Etrac and CTX in mild to medium mineralized ground generally will quit detecting a nonferrous find rather that allow a deeper find be reported as ferrous. This assumes no ferrous as part of the detecting scenario of a nonferrous deeper target.

Interesting to hear how various detectors behave with fringe targets - I often wonder how some folks are able to keep several drastically different machines in their arsenal and still use them efficiently as they jump from one to the other! Seems like it would be a challenge to keep each machine’s idiosyncrasies straight - but like all things, I’m sure it all comes with experience.

It takes a lot of hours and practice and experimenting to learn what the fringe targets respond like. It also requires that you pay very close attention to details of the responses to learn what it good and what is bad.
.....

BTW, "deep" is subject. The soil minerals, composition, density, moisture and target orientation all play a part in how well any detector can "see" a coin. I can hit a 10 inch, flat dime but an hour down the road it might be maxed out to see it at 6.

Thanks, Jason...all good thoughts.
 
I'd mostly agree there,
At shallow depths in bad soil, the Etrac has no problem telling you a target is there, it gets a strong signal from the coin, but the software can't cope with the ground, and iron it is.
Yet in milder soil it doesn't call a deep weak coin signal as ferrous because the software isn't overwhelmed and works as it should.
There's probably a cutoff point where when the signal strength falls below a certain level, the software kicks in and doesn't report it as ferrous.

The ground is the key, you don't get the Etrac calling a coin as ferrous at it's max depth in an air test, so ground software filtering is defo going on, but at what mineral level does it overload and stop working??

Again this is just me thinking out loud, i'm probably miles off course lol

Just an edit to add, if i run my Signum with no ground filter, it will call coins as iron at a certain depth, when i start to add ground filters, it reduces the ground effect and the coin comes back over the border into the non-ferrous side, so there's a level of ground filtering needed in mineralised soil, just how much varies, but if this setting is fixed into your detectors software, you just have to go with what it's set too, and you won't know what you ever missed because it may have sounded as iron.
Now, if we had Calabash's soil we could all but forget about this problem lol


With FBS in mineralized soil, it also depends if you are using auto or manual sensitivity. Some people ONLY use manual sensitivity. In tough soil that can be a mistake. On the Etrac (maybe CTX, not sure), manual and auto sensitivity are handled differently. FBS scans the return signal on 3 separate channels, high, medium and low. In auto sens., the 3 channels are individually set to different levels in order to overcome high mineralization, hot rocks, etc, In manual sens., all 3 channels are set to the same level and aren't able to cut through tough soil as well as auto sens. Manual may go deeper in clean soil, but will suffer in bad soil.

So keep this in mind when reading of some Etrac users struggling in tough soil more than other Etrac users do.
 
With the AT Pro I have noticed that deeper targets seem to give a a higher signal before you dig them. After it is out of the hole it goes to the real signal.
 
if you want deep you gotta go all metal and listen to the thresh hold. Some of the deep silver i've dug didn't even give a vdi. What you have to do is start digging all the super faint thresh hold signals, and learn what they sound like. Just like when you were learning your detector, except no vdi to help.
 
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