Depth issues...

[dewcon4414]

Ive got feelers out for a good water machine my self Steve(MS). Ive seen you over on Tom Ds site. Been chatting him and Clive up for advice. Its nice to have these GURUs out there.... but it is hard to make that first leap into another area like beach hunting. Ive still got several of the posts especially Milke Moutrays on the smartscreen. You never stop picking up smart tips for various sites that you can relate to any detector.

Dew

 

[sgoss66]

Just wanted to report that I had a hard hunt today...my machine was in a near CONSTANT null much of the time; I had to lower sensitivity, run semi-auto, etc. etc. trying to combat it. It was really tough hunting. The incessant nulling made it tough to accomplish much.

However, during the few times I WAS able to hunt normally, I did dig a wheat cent that gave a pretty solid ID and good signal -- at about 8". That was good.

I also was impressed with the machine at one point, in that I kept getting a penny signal but it was iffy and hard at times to repeat. I had nulling on either side of it, and when I pinpointed, it was having trouble locking on, and was giving me iron IDs. I could only get the penny tone by making 1-2" little "Minelab wiggle" type sweeps, and I eventually figured out that I had nails there. I was guessing that that "iffy" coin signal I could get was just falsing off the end of the nails, but it was just a bit too repeatable to pass up. So I started digging, and pulled a large rusty nail out of the hole. I figured that was it, but swept the hole to be sure and still could hear the penny tone in there. Stuck the pro-pointer back in, and found ANOTHER large rusty nail. I thought surely that was it. Swept the hole again, still had the penny tone; I finally was able to pinpoint the penny -- down about 4-5". It was only a memorial, but still -- those nails had to be shallower than, and in pretty close proximity to, that penny. I am impressed that it found it between those two iron hunks!

Thanks all,

Steve

 

[bbqman]

Enjoyed the class , thanks Steve and Bryce ! I think I`m going to give manual 26 a try at that old 1870 house tommorow. All my other settings are as per Bryce and I use the smartfind and only check numbers when in a close iron contact, just as another reason to dig.

 

[Steve(MS)]

As I have mentioned many times over the past, threshold loss with
the Explorers is different than with other detectors.
Just because the null is steady or even long, it doesn't mean
the detector can't give a good signal in the midst.
Bryce has written on this many times as well.
A problem arises when applying the principles
that work on single frq detectors and expect it to transfer
over to the Explorer.

Just because the Explorer goes into a null, it does not
necessarily follow that the sensitivity needs to be lowered.
I hardly ever lower sens. because of null or loss of threshold.
The only reason I lower sens. is if I notice the machine
is running unstable.

Null is by definition the loss of threshold.
Null happens when any measure of discrimination
is applied and the machine goes silent or nulls
when it encounters a metal and/or ground minerals
in the discrimination range.
If the area one is searching has a lot of shallow nails
close together then the main strategy for that is to
go to a smaller coil.
Most of the time I will go over such an area first with
the stock coil and then put on a smaller coil.

This is for any learning the Explorer,
put away while learning it any preconceived ideas associated
with past experiences relating to metal detectors.
Learn it for what it is because it is definitely
different from all other detectors.
When in doubt about its abilities. look at what folks
have been finding with it (even over many years).
HH

 

[sgoss66]

Hey Steve(MS),

Thanks for the info. I am going to ask a few questions, but please understand I'm not being "argumentative." I know you, Bryce, and others are basically "gurus" -- especially compared to me and my whole 2 months on the Explorer, so I'm not taking an "I'm right, you're wrong" tone here, I just want to understand a little better, and share my feelings.

I have never used a machine that gave a threshold tone in disc. mode, so I don't have any pre-conceived ideas about threshold and nulling and all. This is all new to me, and I feel I have a "clean slate" to work with, in terms of my impressions of "nulling of threshold."

Having said that, it sure seems to me like there are times when a good target can signal through a "null," and times it can't. In other words, there are times when the "null" seems to be "weaker" or "less strong," and other times when it's VERY strong (for lack of a better word). To me, it seems like when the machine is "heavily nulling," it's hard to get a signal; when it's nulling more lightly, or just "going into" or "coming out of" a null, you are more likely to get the signal from a good target to "break through." It is really hard to put this into words, but my definite impression is that if you are in a very "solid" and "strong" null, it would take a very strong target to "break" that null.

I have concluded from this, (that some nulls seem "strong" and others "not so strong") is that the "strength" of the null can tell you "to what degree is the iron under the coil overwhelming the coil" -- i.e., how strong is the "iron masking potential?" If the iron is "big" and or "plentiful," the likelihood for iron masking is high, and likewise the "null" is strong. Meanwhile, if you have smaller and/or less numerous pieces of iron under the coil, the signal from a good target is more likely to "reveal itself" to the machine, and thus "break the null." My impression is that maybe when you are in "strong" nulling, that means there is likely too much iron under the coil and thus any signal from a good target would be "lost" in the iron signal (i.e. "masked," and thus will NOT be heard "through the null.") On the other hand, I think when you DO hear a target "through the null," it's a "weaker" null -- i.e. smaller and/or more sparse iron -- and therefore the "degree of masking" was lower thus allowing the target to be "seen" by the machine.

This is somewhat semantics though, as both you and Bryce have offered two pieces of advice to deal with nulling -- slow down (i.e. giving the machine a better chance of separating targets), and using a smaller coil (which would reduce, in some cases, the "amount" of iron being seen by the coil at any one time, and thus less likelihood of iron masking). These to strategies obviously help with the problem, irrelevant of all this conjecture on my part. I guess my only point is, it sure seems to me like there are times when you WILL NOT hear a target through the null -- when the null is particularly "strong," "heavy" nulling. Again though, it really doesn't matter; if my understanding is correct, it's not the nulling itself which is causing you to miss a target; the nulling is just a "symptom" or "manifestation" of the degree of "iron masking" under the coil at any one time. In other words, the "strength" of the nulling, if I am correct on this, is simply revealing to you the "strength" of the iron signal being received by the coil, and thus the likelihood that any good target is masked -- and thus invisible -- to the detector.

Not sure if this makes sense, as again -- it's somewhat subtleties/semantics that I'm discussing, but I'd be interested in any comments. I may be totally wrong, but I am not sure if it would be totally true to say "you CAN hear a good target through nulling." I'd say it may be more correct to say "you can AT TIMES hear a good target through nulling" -- i.e. maybe, maybe not -- it depends on how strong the "null" is (i.e. how much iron is under the coil at any one time, and thus to what degree can that iron "mask" a good target).

Steve

 

[MNCoinhunter]

Or it may be that "heavy nulling" as you call it, is the result of no other targets but iron being there in the first place ??

Like I needed to add to the confusion right? lol !

 

[ohio fred]

As with me i say on almost all machine the adjustments you make are after the signal is received not as it is going out,so iam saying the adjustment for nulling or hearing a coin is after it comes back into the box and to speaker or headphone,i believe the signal going out has a few adjustments we assume everything we do is to that signal but it is actually the signal being adjusted after it comes back from the object into the box.Now if that don't add to the confusion.

 

[Steve(MS)]

This is somewhat semantics though, as both you and Bryce have offered two pieces of advice to deal with nulling -- slow down (i.e. giving the machine a better chance of separating targets), and using a smaller coil (which would reduce, in some cases, the "amount" of iron being seen by the coil at any one time, and thus less likelihood of iron masking). These to strategies obviously help with the problem, irrelevant of all this conjecture on my part. I guess my only point is, it sure seems to me like there are times when you WILL NOT hear a target through the null -- when the null is particularly "strong," "heavy" nulling. Again though, it really doesn't matter; if my understanding is correct, it's not the nulling itself which is causing you to miss a target; the nulling is just a "symptom" or "manifestation" of the degree of "iron masking" under the coil at any one time. In other words, the "strength" of the nulling, if I am correct on this, is simply revealing to you the "strength" of the iron signal being received by the coil, and thus the likelihood that any good target is masked -- and thus invisible -- to the detector.

Not sure if this makes sense, as again -- it's somewhat subtleties/semantics that I'm discussing, but I'd be interested in any comments. I may be totally wrong, but I am not sure if it would be totally true to say "you CAN hear a good target through nulling." I'd say it may be more correct to say "you can AT TIMES hear a good target through nulling" -- i.e. maybe, maybe not -- it depends on how strong the "null" is (i.e. how much iron is under the coil at any one time, and thus to what degree can that iron "mask" a good target).

Steve

At this point we are entering the world of theory of when a good target is masked and when one is not.
The presence of the "null" could be done away with simply by using ferrous sounds and running a wide open screen.
Then the null is gone and replaced by a constant barrage of iron low tones if there is a lot of iron in the ground.
Masking can occur when there is too much iron under coil at a given time that can cause a non-report of a good target.
The orientation of nail(s) in relationship to the angle of sweep of a DD coil can cause a non-report of a good target.
This is true for any detector that uses a DD coil.
The strength of the "iron" signal can cause masking on a nearby good target.
This is true for any metal detector.

But that is all theory and you can bet it doesn't stop me or others of "wading" out in the trash and detecting
an area and many times pulling out good finds.
The idea to overcome is "it is nulling, therefore I will not find anything".
A good idea is to use your Explorer for say 6 months, give it the benefit of the doubt and use it under
many situations and then decide what you think about it.
Put in as much time as you can on it.
Way back there was a guy who couldn't get but 7" deep, we told him, "it will only go 7" but turn
it on, it will go deeper, haha.
The point being there is more to it (Explorer) than what can be acquired by casual observation.

 

[sgoss66]

Appreciate the insight, Steve(MS) and you raise very good points. I do obviously need alot more experience on the machine.

One question -- I have had times where I go into IM, open it up completely (set mask at 31), and STILL have dead nulling. How can that be possible? THAT, more than anything, has been the one thing that totally fries my brain...

Steve

 

[Steve(MS)]

Since I don't have the SE, I can't answer that question.
I assumed the SE will allow in the iron mask mode to fully clear the
screen thus having a sort of "all metal" effect.
Perhaps you can use program mode and hit clear screen and
see if you have the nulling effect.
If I open up the screen in iron mask on mine, it will signal on everything
and not go into a null.
Maybe somebody with a SE can verify whichever way it is....
Or you can get with someone else who has the SE and find out.
For sure you need to find out, it would be a real bummer if your detector
wasn't operating correctly.
Or maybe your definition of null is different from mine.
Null is a silence due to discrimination of a desired range.
Null implies the use of threshold...well at least I think so.
So you have some disc set and an audible threshold then while sweeping,
the audio goes silent----this is my understanding of null.
If no audible threshold then since the machine is quiet anyway, there is
no null, either the machine is quiet or it sounds off at the presence of
a metalic object within the accept perimeters of disc control (in an ideal world).

 

[BJ in Okla.]

The SE at IM 31 is not wide open,,,one more click to AM,,,All Metal is wide open....
BJ

 

[MNCoinhunter]

Instead of changing my preferred IM setting, I just use the menu > select > clear option. Is there a difference between that and using IM 31 ? You would'nt think so, but now I am going to try it first thing tomorrow in my iron-infested backyard.

 

[Steve(MS)]

Ok, decided to add the following.
There may be times of null without metal objects present.
Especially with high sensitivity settings sometimes ground
minerals can cause a null, perhaps this is what you are
experiencing....but even then, the "ground signal" should give
a high pitched tone if you are using conduct sounds or
a very low pitched tone if you are using ferrous sounds.
Personally, I don't pay much attention to nulls, that is
if my detector nulls, it doesn't bother me in the least.
I generally know there is iron in the ground because of the
chirps--that is what I listen for to know I am in nails.
Since I detect trashy areas to start with, I am generally looking
for nail infested areas.
So I know there is stuff almost always under my coil.
If you want to know how deep the nails where you are detecting
watch you depth meter, it will give an indication in real time.
If your depth gage is pegging the meter at lot, you will likely need
to check over that same area with a smaller coil.

Finally it sounds to me you would likely benefit joining one of
your friends who has the SE.
Ask him some questions that concern you, let him try yours out
for a little to see if it is working correctly.
These machines are great at what they do and I would hate to
see you give up on it, at least till you get to know it well enough
to make up your mind about what it can or can't do.

 

[ohio fred]

The null i thought is when using or listening to threshold in background it go silent only for this reason it is iron or object you have discriminated out,you can turn threshold off but most prefer to hear just a little to, hear it go silent so they know there is a object under coil,some machine when you listen to threshold and it is a deep object lets say whites mxt and you are hunting in threshold for deep targets depending on were you have set the discrimination it will go silent over that target but on good target to deep to register on screen the threshold will raise slightly like going over a speed bump in parking lot.I have not noticed that on the explorer II but don't have a lot of time in on it but i do know going to a very hot sight were there is constant nulling even using manual 8 or 9 power at best it will still tell you if a coin is there don't know if it misses any have know way of knowing.But iam still under the belief that the power signal gos out and when the signal returns this is what you are hearing the adjustments you are making to a machine is after the signal returns.So all the programs and stuff people use is only adjusting return signal to hear it better or more to define it.Like adjusting gain to hare deeper signal i believe it works but i believe that signal is there on the return no matter what you set it at but you are adjusting it to hear it after it returns and go through the box to speaker or headphones.,it is not finding deeper targets on the signal going into the ground,it is clarifying them on the return signal after it comes into the box.

 

[sgoss66]

Couple things --

BJ -- you are right -- and I know that. Hopefully I was not SO dumb as to actually put it in 31 (as I said I did)! I HOPE I ran it one more click, past 31, and into AM, though maybe I didn't. Because you are right -- 31 is NOT wide open, it's one click away from wide open. I will re-check, as this could be the issue. HOPEFULLY I didn't have a "brain fart," but I'm thinking I did. Since that's how I described it in my post, that very well may have been what I did -- ran it to 31, and didn't run it one more click to "AM" -- which WOULD have been wide-open. I'll verify.

ohio fred -- I think you are correct that on SOME machines, any adjustments you make only affect the return signal -- i.e., the way the machine processes a signal it has already received. Awhile back, I verified with NASA Tom Dankowski that, on my F70 and Gold Bug Pro, that when adjusting gain and/or sensitivity on those machines, all you were doing was "amplifying" or "de-amplifying" weak signals. HOWEVER, reading Andy Sabisch's "Explorer and E-Trac Handbook," (which I am doing right now), it suggests that adjusting sensitivity on these FBS machines actually adjusts the transmit power of the machine. I'd like to have this verified, but this does match my experience. It did not seem like you were "sending out more power" with those Fisher units when you raised sensitivity. Just allowing the machine to audibly report a smaller "size" or "strength" of signal through the speaker/headphones. You know that threshold "speed bump" you mentioned? THAT is what I understood that the Fisher machines would allow you to hear in higher sensitivity settings. Since in disc. mode there is no threshold on the Fisher machines (and thus no "threshold speed bump" for you to listen for), raising sensitivity was equivalent to letting you hear those little "bumps" in the threshold -- it amplified that little signal, that could be a deep, weak target -- and in that way, in a "sort of" way, can kind of "increase your depth ability". But, not in a direct "more power" type of way. HOWEVER, when I run up sensitivity on my SE Pro, it DOES seem like you are raising the "transmit power." There IS a NOTICEABLE loss of depth in lower sensitivity settings with these machines, and vice-versa. When you find a deeper target in clean ground, running high manual sensitivity, and then progressively lower the sensitivity, you will reach a point where you "lose" the target. It is MUCH different behavior, when adjusting sensitivity on this machine, that it is when adjusting sensitivity on my Fisher machines. GAIN, on the other hand, on the Explorers, IS simply an adjustment in "volume" of weaker signals -- it is DEFINITELY an "after the signal is received by the machine" adjustment.

McDave -- not familiar with this "clear" function; need to read up on that, as that would be an easy way to quickly switch your machine into a "wide open" mode...

Steve(MS) -- yes, we are both using the word "null" in the same way. I mean the same thing you do -- a temporary silencing of the background threshold tone. I need to make sure that I DID go all the way to AM in my iron mask, and not just to 31 as BJ pointed out. But, further, I have a really hard time when my threshold "nulls," and it is because I don't know what the machine is actually doing. If it was simply as easy as "null" can just be thought of as "your machine is detecting iron," then that's fine. And listening to you and Bryce, that is simply all it means. Thus -- you should slow down, move your coil slow to give it time to maybe see a good target adjacent to all that iron, but also know that you might want to switch to a smaller coil -- as all that iron you are hearing as a "null" IS masking some good stuff -- and thus a smaller coil can help. However, I think losing the null is implying to my "brain" that the machine is "dead" or "turned off" while in the null -- and I think others get this impression, too. It may likely be a WRONG impression, but still -- I think maybe that's why these machines get a rap for being "slow recovery" units. When that "null" lasts for five or ten or more seconds, people say "hey, why has my machine not recovered from that iron signal yet..." when in reality, maybe it's because there are a WHOLE BUNCH of iron pieces and your machine never sees a spot of clean ground (which, if that clean spot of ground existed, would have allowed your threshold to return). I do know this -- when NOT nulling, but running over a bunch of not-discriminated targets, my machine is capable of rapid-fire tone responses, so I don't think it is a "slow" machine; it's just that the "null" -- especially when extended over a long period of time -- it implies to my brain that the machine is "dead" or "unable to detect." I need to eliminate that, I think, because I think the truth is that if there is a good target there, and it is NOT TOTALLY masked by the iron -- i.e., it's visible to the machine AT ALL, the machine will see it -- "through the null." I just have a mental block that when my machine is in constant, sustained nulling, I need to "get the heck out of there" and find some clean ground. That's why, Steve, it amazes me that you say you actually LOOK FOR those iron heaps, and purposely hunt there. You must LOVE guys like me -- we run away from the iron trash, leaving all the goodies for you!

I am going to work on changing my thinking -- that "nulling" simply means "your machine is detecting iron," and that the "null" is the equivalent to running an open screen and hearing a bunch of "low tones." It's nothing more than that.

Thanks for all this discussion, guys. It is helping me to change my thinking about "nulling." Brief nulls don't bother me. My brain says "I just ran the coil over a nail." It's those long, sustained, "I haven't heard a threshold tone in the last five minutes" type of nulls that freak me out! You pull goodies from ground giving you that type of nulling, Steve/Bryce? Really? I'd love to see that first-hand; it would help me completely eradicate this "mental block" I'm struggling with...

Steve

P.S. Oh, and by the way, Steve(MS), I have NO INTENTION of giving up on this machine. It's too good of a machine; I simply need to learn how to use it in an expert way. I thought I had it figured out fairly well, for a beginner; however, recently, I've been hitting road blocks in the learning process...

 

[ohio fred]

n/t

 

[Steve(MS)]

[b"]However, I think losing the null is implying to my "brain" that the machine is "dead" or "turned off" while in the null -- and I think others get this impression, too. It may likely be a WRONG impression, but still -- I think maybe that's why these machines get a rap for being "slow recovery" units. When that "null" lasts for five or ten or more seconds, people say "hey, why has my machine not recovered from that iron signal yet..."[/b]

Steve, I had a feeling this was where all this was headed early on.
The internet can be a wonderful tool but at the same time there can be as
I will say a biased comentary, among other things.
Generally I could care less and stay silent since the Explorer's track record
speaks for itself regardless of what I may say or anyone else.
But I am hoping in your case that I can steer you toward keeping an open
mind.
Get to know this detector inside and outside then put it up against whatever
other detector(s) you wish to.
You do realize if what you think you are experiencing so far with your Explorer
.....6"depth and a null that renders it useless.........then you would be better
off with an Ace 250.
Haha, I hope not.....since I haven't tried out the 250 yet.

.

 

[sgoss66]

Steve(MS) -- maybe I HAVE read too much! I don't know for sure, though, why I have this "mental block" with the null -- maybe that's it (too much reading on the 'net), maybe not. Like I said, nulling for a couple of seconds over a nail or whatever causes me no concern. But when I go for a good, long time with no threshold...it "creeps me out" for some reason! Don't know for sure why, I'm trying to figure that out. Being a scientist, the only way I know how to deal with things like this is to think, and study, and dig into the details. That approach exasperates some folks who are trying to help me, I know. But it's the only way I know of to work through things, in my mind (yeah, I know, it's quirky... ) Thinking is one thing I rely on, but at the same time, it can be a hindrance at times, too -- in that when I don't understand something, and can't figure it out, I remain uncomfortable with it and thus tend to avoid it (like the thick iron trash -- don't understand what my detector will do with it, so I avoid those areas!)

The other issue I have is, every time I have tried to "sort through the trash," and dig tones that are "iffy," amongst nulling, they have almost always turned out to be just nails or other iron junk. Once or twice I have pulled a good target (clad coin) that was an iffy signal, with nulling nearby, but for the most part, this is the toughest, most challenging issue for me -- and probably still too "advanced" of a skill for me to try to use. I would gladly avoid these more difficult signals -- and focus on the clearer/cleaner ones; problem is though that most sites I have ever hunted are HAMMERED sites, and if I focues only on the "good" silver signals, I'd never dig a target! In other words, I realize that to make the good finds, they will either be deep, and/or partially masked by trash, in most cases, where I hunt. But, I don't have enough experience finding silver in the FIRST place, as the "easy" silvers are by and large gone where I hunt. And, without a good deal of experience finding silver under my belt, it then makes it that much more difficult to be able to find the TOUGHER silver targets. See my dilemma? I WANT to go into the trashy areas where the remaining silvers might be, but I lack experience with the machine on the EASY silver targets, let alone on the "difficult" targets. That's why I'm here on the classroom forum, trying to shorten the learning curve, and get a "crash course" in terms of experience that you all have gained through years of finding the good stuff amongst the trash. While I appreciate all of your help, I know I'm exasperating you at the same time. I would LOVE to dive into a trash pile alongside someone who really excels at sniffing out the hidden goodies with these machines -- and then run my machine over a few of their located targets, to begin to understand what to look for. To me, a nail false and a good target would seem like the same thing...though I'm sure that's not the case to someone with experience.

Anyway -- no Ace 250 for me! I do want an open mind, and intend to keep it open as best as I can. The problem I fight is that my mind, like it or not, constantly analyzes data. It just does, whether I intend to or not. And I simply don't have enough "good" data (finding good targets, picking the good stuff from trash, etc.) to offset the "bad data" acquired from frustrating experiences of dealing with hunted-out parks filled with all manner of trash. When I spend hours and hours, on dozens of days, hunting a 120-year old park that has seen TONS of traffic over that period of time, and yet have never pulled ONE SINGLE silver coin from it, it's a challenge for me and my analytical-type brain NOT to start drawing incorrect conclusions -- about how to find old coins, about how well the machine I am using is suited for the task, etc.! That's the challenge for me. When I have these types of experiences, my brain keeps asking "why," and searching for the explanation. And I don't have a good answer to that "why" question, yet -- aside from overall inexperience -- and in particular, inexperience with Explorers. For now, I'll focus on the fact that NULLING, in and of itself, is not a hindrance, but rather is just an indication of iron, and the masking issues that go along with iron. Slowing down, and switching to a smaller coil, may be answers to the issue, but fleeing the trash is apparently NOT the answer!

Thanks Steve for your help.

Steve

 

[MNCoinhunter]

Sounds like what you (or we) are after can only be gained by putting in some time in the field. Like someone else mentioned...if my Explorer goes into a long null, I consider it a nice quiet break from the ever-present threshold tone. And I will actually slow down and scan the area to see if anything squeaks through the silence. And the only way you can really be certain that you are not missing a good target is to dig absolutely everything. But who wants to do that? I sure don't. So if there is nothing but silence through the null, I tend to lean towards nothing good being there anyways. Might I miss something occasionally by detecting that way? Possibly. But I'm not going to lose any sleep over it. If there is one thing that I have noticed with the Explorer, is that coins have a signature response all their own. And aside from the sporadic rusty nail, it is almost always what I believe it is. I had a signal today that was telling me it was either a penny or a dime, as it was bouncing between the two. Turned out to be a 1914 wheatie. The only thing I knew for sure was that it WAS a coin in some form.

 

[Steve(MS)]

No, you are not reading too much.
As you know reading will increase our knowledge.
If however I bought a Garrett and read info about it among say Whites users,
I would likely have an incomplete amount of knowledge about my detector.
I think you see the meaning in this.

Those hammered old trashy parks, of course you are dealing with many possibilities
as I am sure you have already analyzed many different ways.
At this point, I will not insult your intelligence with any easy quick answers.
I know what I would do but my ways may not fit your preferences.
I do agree it is getting tougher all the time trying to find places or areas that haven't
been hunted to death.
One way you might be able to bridge the gap between hunting hard hit areas and
only doing casual clad hunts is to find a few house places to detect, if that is within
the realm of possibility for you.
If you have family or friends that would allow you to detect and dig some, that would
be great.
Obviously it is important to build on your learning experience.
Go for solid signals then after that you can experiment with the iffies.
Try to put the iffy signals in categories.
When you get an iffy, see if it repeats when you turn 90 degrees and resweep.
Consult your depth meter while checking out an iffy.
See if when you pinpoint that the spot is the same as where the iffy shows
up while in disc mode.
Try your best to mentally remember just how this iffy sounded and after you
dig it up, reflect on results, whether negative or positve.
Try to remember how the cursor was reacting while sweeping over the iffy.
Then try to put all this together to try to understand what your detector is telling you.

Really the main problem you should have learning this detector is the diff between
a deep high conductive deep coin, such as a dime, copper penny and quarter and
a falsing nail.
Those signals or sounds below the top of the screen are easier to discern
what they are. In other words, you should be able to tell diff between
ferrous and non-ferrous on those signals.

You will know when you are going for the "correct" iffies if what you are digging
are bent nails or nails with globs or perhaps get fooled by a thin piece of iron wire.
Never assume you are not learning anything just because you dig a rusty nail or
whatever.
Use your keen analytical mind to "figure out" just what the heck is going on.
If for some reason you hit a learning brick wall, experiment with the settings
to see if you like another set of settings better.
Among those is the option of conduct sounds or ferrous sounds.
Normal or audio 1.
The use of a degree of iron mask or a "wide open" screen.
If you have Andy's books, look at the settings some use and see if any of them
fit you better.
Get out in your yard or park and change some of those settings and see what you think.
Warning! The one not to mess with much is the threshold tone, for that one, find a setting you
like and then leave it there.

One more thing about the trashy park, a smaller coil may give you an edge in the heavier
trashy areas and at the same time, give you some good learning experiences.
Hope this has been of some help.
HH