Hunting in all-metal

tnsharpshooter said:

When you are using discrimation side of detector and accepting all vdis ( ferrous and nonferrous) you are indeed allowing detector to use filtering-- which will limit depth moreso vs using true All Metal.

F75 is a good example one of the originals,,,,you can run in disc mode use 0 disc,,and you can run in all metal--- different setup altogether,,,,with AM being deeper overall.

An operator also using the F75 example as I have,,,take a 9" deep dime,,,what a user is likely to notice,,,coil position using discrimation mode,,,far more critical to get dime to sound off. Running true AM coil position more forgiving,,,meaning far easier to locate this target based on audio.

Not all detector feature true all metal.
At Pro don't
CTX
Etrac

At Gold does
Deus does,,hard to run though
White's V3i does

Juat to name a few.

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So the discrimination in the digital detectors, prevents the user from hearing it, it doesn't prevent the detector from seeing it. Hence hearing the threshold drop out on discriminated targets, you don't hear a specific tone, but your detector sees it. Discrimination does not change the transmit power on your detector on digital machines.

Here is one, I can find the other if you like,

http://www.metaldetectingworld.com/metal_detector_sensitivity_depth.shtml

Big Treble said:

So the discrimination in the digital detectors, prevents the user from hearing it, it doesn't prevent the detector from seeing it. Hence hearing the threshold drop out on discriminated targets, you don't hear a specific tone, but your detector sees it. Discrimination does not change the transmit power on your detector on digital machines.

Here is one, I can find the other if you like,

http://www.metaldetectingworld.com/metal_detector_sensitivity_depth.shtml

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Correct,,,using AM doesn't change transmit power,,,but does change how received signals are processed.

A wider gate so to speak,,,vs narrower using discrimination side.

You are a White's V3i user I think.


The mixed mode audio,,,,for open field hunting,,,what it will do for a person,,,is allow a user to hear more targets both shallower and deeper,,without super duper coil placement. Edge of coil is more reactive,,vs the center using just discrimination side of house.
And a user will notice,,,if target is actually not too deep to be detected ( on discrimination side),,,as target comes moreso under the center of coil,,,,tone is provided on the discrimination side,,,and then a person will know the target is nonferrous vs ferrous usually.

tnsharpshooter said:

Correct,,,using AM doesn't change transmit power,,,but does change how received signals are processed.

A wider gate so to speak,,,vs narrower using discrimination side.

You are a White's V3i user I think.


The mixed mode audio,,,,for open field hunting,,,what it will do for a person,,,is allow a user to hear more targets both shallower and deeper,,without super duper coil placement. Edge of coil is more reactive,,vs the center using just discrimination side of house.
And a user will notice,,,if target is actually not too deep to be detected ( on discrimination side),,,as target comes moreso under the center of coil,,,,tone is provided on the discrimination side,,,and then a person will know the target is nonferrous vs ferrous usually.

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Yep am a V3i user, I didn't want to try to cover the channels from the V3i perspective since I knew it the V3i was your first machine and you mentioned it challenged you. Here is a pic from the Advanced Users Guide explaining the difference in the channels, and this indicates it is purely audio. As a mater of fact the Mixed Mode you speak of is shortened from Mixed Mode Audio.

The two factors affecting the depth are Coil size and Tx Power. Changing an audio setting has no bearing BUT depth can change TID, and if TID is changed and could appear as something you machine thinks you want discrimated out, and doesn't report.

Their is an entire chapter devoted to this. I can provide you a link to download it. Or email it to you if you wish.

Big Treble said:

Yep am a V3i user, I didn't want to try to cover the channels from the V3i perspective since I knew it the V3i was your first machine and you mentioned it challenged you. Here is a pic from the Advanced Users Guide explaining the difference in the channels, and this indicates it is purely audio. As a mater of fact the Mixed Mode you speak of is shortened from Mixed Mode Audio.

The two factors affecting the depth are Coil size and Tx Power. Changing an audio setting has no bearing BUT depth can change TID, and if TID is changed and could appear as something you machine thinks you want discrimated out, and doesn't report.

Their is an entire chapter devoted to this. I can provide you a link to download it. Or email it to you if you wish.

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The V3i didn't challenge me,,,just didn't act and do as well for me vs some others.
Ergonomics didn't help either.

Some additional thoughts.

When you are running in disc mode,,,,a detector needs more info for it to make a decision between the differing nonferrous,,,as well as be able to distinguish ferrous from nonferrous.

Now it is possible for a detector to register a nonferrous object as a ferrous object.

But these phase shifts have to be examined by engineered circuitry.

In All Metal (true),,, a phase shift is also detected,,,but not as much info is needed,,,and so on deeper targets,,,less info is usually the case,,,but the detector works with this info,,,and give user the signal.

This being able to recognize the difference between deeper targets,,, as being ferrous or nonferrous,,,is one of the many challenges,,,and to add being able to actually ID even different nonferrous targets at deeper depths another challenge.

tnsharpshooter said:

The V3i didn't challenge me,,,just didn't act and do as well for me vs some others.
Ergonomics didn't help either.

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Ok sorry for the poor reading comprehension.

Big Treble said:

Here is a pic from the Advanced Users Guide explaining the difference in the channels, and this indicates it is purely audio. As a mater of fact the Mixed Mode you speak of is shortened from Mixed Mode Audio.

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It is not correct to term it an audio mode. You set the audio to determine which data channel you are listening to. You can listen to the DISC channel (the motion detection channel), you can listen to the All metal channel (which is the non-motion detection channel), or you can listen to both. The V3i uses both motion and non-motion in its detection. If you hunt listening to only the All Metal Channel, the target data is still being processed by the DISC circuits. It won't output any DISC channel audio, but it does provide VDI and other target information. All Metal "goes deeper" because it does not do any filtering to the target signal. DISC channel processing has to deal with the motion (which generates noise) and any level of discrimination you apply (like discriminating from -95 to 0, or whatever). When you start filtering the signal, you lose information. Because All Metal doesn't do any of this filtering, it doesn't lose the same information the DISC channel does.

The two factors affecting the depth are Coil size and Tx Power. Changing an audio setting has no bearing BUT depth can change TID, and if TID is changed and could appear as something you machine thinks you want discrimated out, and doesn't report.
.

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Coil size has more of an effect than Tx power. A bigger coil can project a bigger field. On the V3i, you can turn on Tx Boost. This will increase the Tx voltage from 10v to 30v. That is 3x the voltage. However, this will provide a depth increase of 1, maybe 2 inches. Increasing TX amplitude has rapidly diminishing returns because the depth gain does not compensate for the quick drain on the battery.

How deep you see is based upon how sensitive your receive coil is and how good your processing circuitry/software is. A sensitive Rx coil will be able to pick up on faint return signals. Good processing circuitry/software will be able to pull those faint signals out of the background noise. Another big factor on depth is how accurately your coil is nulled. Our detectors are in most cases "induction balanced" units. If the Tx and Rx coils do not perfectly null each other out, you will get noise. Extra noise hides deep, faint signals. That extra noise is amplified by the pre-processing gain amplifier. (in V3i terms, the Rx gain)

On the V3i, changing audio DOES have a bearing, because it determines what data channel you are listening to. If you are listening to just the DISC channel, you will NEVER hear a coin on edge. However, if you are listening to the AM channel, you will get a slight increase in threshold. If you use the AM audio channel you will find your deepest targets by listening for slight bumps in the AM threshold that the DISC channel will not hear.

There are a lot of factors that contribute to depth. Coil size is just one of them. If power trade offs were not so severe, that also would be a factor. A stronger transmit field will produce a stronger induced field at the target. However, since the strength of the induced field decreased proportionally with the inverse of the depth cubed, you don't get much bang for that buck.

tnsharpshooter said:

Using the term "all metal".,, can be a bit misleading.

For example,,,fbs/fbs2 machines ,,,,running open screen,,,is not technically all metal,,,meaning don't expect additional depth capabilities with tone provided.

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Agreed. My CTX does not have an all metal feature. Open screen is not all metal. I can't imagine how deep that machine would be if it did though

Now my CZ21 and Excal have all metal.

I beg to differ about the ctx not having all metal mode.

(Quote ( Randy Horton) ak digger he was one of the testers for the ctx.

Note that coin mode 2 has fe line 35 rejected ,relic mode pattern 2 has all targets accepted ( all metal) if the iron you were trying to get a solid signal on was bouncing around the fe line in pattern 2 of your relic mode, it would be nulling out any audio tone on the fe line 35 targets when using pattern 2 in the coin mode .

So if you want to hear everything you have to be in relic mode or pinpoint sizing.)

If you move your coil slower you will not miss much just give the ctx time to analyze the targets go to fast and you will miss some targets that are tight with iron .

You may also find adding disc is not a bad thing say 31 to 35 line disc out let's you cover more ground because your not constantly checking iron all the time .
sube

sube said:

I beg to differ about the ctx not having all metal mode.

(Quote ( Randy Horton) ak digger he was one of the testers for the ctx.

Note that coin mode 2 has fe line 35 rejected ,relic mode pattern 2 has all targets accepted ( all metal) if the iron you were trying to get a solid signal on was bouncing around the fe line in pattern 2 of your relic mode, it would be nulling out any audio tone on the fe line 35 targets when using pattern 2 in the coin mode .

So if you want to hear everything you have to be in relic mode or pinpoint sizing.)

If you move your coil slower you will not miss much just give the ctx time to analyze the targets go to fast and you will miss some targets that are tight with iron .

You may also find adding disc is not a bad thing say 31 to 35 line disc out let's you cover more ground because your not constantly checking iron all the time .
sube

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Don't think CTX or any fbs detector has true all metal,,,,neither does this gent.
http://www.dankowskidetectors.com/discussions/read.php?2,110177,110268,quote=1

tnsharpshooter said:

Don't think CTX or any fbs detector has true all metal,,,,neither does this gent.
http://www.dankowskidetectors.com/discussions/read.php?2,110177,110268,quote=1

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The poster said he hunts in all metal . Your talking about true all metal.

The ctx well hit deeper in relic mode and pinpoint sizing . All other modes will not be as deep because the 35 line is disc out .

So when people say there hunting in open screen they really are not because the 35 line is disc out which makes these modes not all metal.

I only am pointing out that the ctx well find all metal in these 2 modes because nothing is disc out .

Is it as deep as true all metal no but it is deeper than the other modes.

Is the ctx a true all metal no.
But it is as close as you can get using the ctx .sube

Since were talking all metal here ,here's a little tip on the ctx if you run relic mode or pinpoint sizing and all other modes .

Target trace kind of peters out at 7 to 8 inches at 23 manual ,now if your running in pinpoint sizing or any other mode if you crank your ctx to 30 manual you will go deeper with target trace that means it well build targets deeper .

However being in a motion mode such as relic can get quite noisy but in pinpoint sizing since it's not a motion mode you can crank it all the way and have very little falsing compared to relic mode or the other search modes .

At 30 manual it well build the best target you can get out of the machine that's because target trace is tied to sensitivity , the higher the sensitivity the deeper trace well build . The two are separate circuits but work together as one .

As far as true all metal my ears have finally forgiven me when I used it on other machine in the past . I really like how the all metal is set up on the minelab machines very quite compared to past true all metal machines .

The ctx is not a true all metal machine but is a improvement over past machines . As far as true all metal not good for parks fairgrounds and social places .

In the woods with few targets it would be great but not where I hunt . sube

By the responses to my posts one can't help but wonder if some postsers replying have ever hunted in threshold all- metal
Not being picky but I cut my teeth on analog and almost never use disc !
I understand the physics of true all metal which anyone whom can read can decipher
I was seeking real world users and comments
Thanks

Re all metal

The all metal setting is not the same on different machines. For example, my Tesoro Tejon has a true threshold based all metal mode, it's an analog machine and will go crazy deep in this setting. The trigger forward second discriminator is a discrimination mode, I use it to check targets but will often find that the target is beyond the range of the discriminator. On my F75, and all other digital machines that I know of, the all metal setting is a computer generated simulation of a threshold based all metal setting, it gives you the "feel" of all metal, but is no deeper than any other discriminate mode.

I ALWAYS hunt in all metal. When I get a signal then I start switching to disc. patterns for better identification.

Thank you for teaching me something. I now own a White’s DFX, but am not totally familiar with it. I haven’t hunted in 24 years, and when I did, it was with a detector that always hunted in all metal mode with no discrimination. The only way I could analyze a target was that the pitch would be higher and brighter if target was a nonferrous metal. I enjoyed those days and i think I,Will run my detector with very little discrimination and dig most everything.
Thanks

I run both at the same time. Aka RT channel sounds on all targets while ST channel can discriminate targets from responding through the ST channel.

Unless the ground is very clean, AM means a lot of digging. To me, it is not an efficient way to hunt. But I can understand it's use in limited locations. I am not a beep and dig kinda guy. I like discrimination and being able to build patterns to maximize my hunting time.

As for the CTX, the tones are better with some discrimination. Blocking out the bottom knocks out a lot of iron. Blocking out the right side knocks out unwanted ground noises. Blocking out top left knocks out wrap-around. Blocking out some of the left side also knocks out ground noise. This helps clean up the processing and makes the tones better in the open parts of the screen. Even with a lot of discrimination, the CTX will still produce clean full tones.