F75 LTD/SE MONOTONE VS ALL METAL ?

Tom,

I know you've stated in the past that the F75 LTD/SE in BP mode, with zero disc and monotone provides the optimal unmasking capabilities.

My question is, what is different about this setup vs hunting in BP all metal mode? Seems like either one will have you glued to the screen, and AM mode is in my experience more stable (provided you have EMI to deal with).

At remote relicy type sites I've been running 0 disc, 99 sensitivity, with 3-tones and BP mode and have been picking good targets out of the the infamous bed of nails type of environs. Am I going to increase my keepers if using monotone, or all metal mode?

Here are three coins I recently plucked out of thick iron:



This V nickel still has rust spots from the nail it was next to:



Can you shed some light on this? If I can increase my finds, then I'm all for monotone mode for relic hunting

Thanks,
Brian



Edited 1 time(s). Last edit at 03/19/2012 03:16PM by Cal_cobra.

All of your questions are answered in:

Rcpt Ack of F75 LTD prototype
COMPILATION #1
COMPILATION #2

(((You should ask this question in any one of the three mentioned threads..... as it is very specific to those specific threads)))


First............ it would be nearly impossible to run the F75 in Disc mode.............. with 1-tone. EVERY little fleck of rust or nail .... will audibly report. And with a Sens setting of 99........ there is no modulated audio. Every little fleck would be full volume. The only form of ID would be the VDI. And to keep you eyes 100% glued to the VDI faceplate (of which would be rapidly flashing volumes-and-volumes of numbers at you...... much faster than your brian can comprehend/analyze) ............ you will instantly realize how much we hunt by 'audio'............. and not any VDI. The VDI is a distant secondary input. In this configuration, you will fatigue in a matter of minutes...... ............ and render this type of control panel set-up as 'unusable'.

IF IF IF your intent is to remove absolutely every fleck of metal out of the ground.......... this would be one of the configurations/ways to perform this function; however, you would find the true auto-tune all-metal mode to be much better....... due to the modulated audio and better 'audio sizing' of targets. Said differently: If you are in ID mode with Disc 0 ............ it is hard to tell the size of the target in this mode......... and it is also hard to tell the depth of the item in this mode.

If you are wanting maximum unmasking abilities/capabilities in trashy areas............. and are NOT performing a pit-digging/site-excavation (removing every fleck of metal)............. stay in the ID mode. You should select 1-tone whilst in the ID mode......... but you MUST use discrimination....... JUST BARELY enough Discrimination in the ID mode.... so as to knock out MOST (but not all) of the iron. This is 'usually' a Disc setting of '6' with the F75/F70. (((Your specific site/conditions/decomposition-status of the iron may require a slightly different Disc setting))). Nails will snap/crackle/pop/click/tick............... but NOT give you any half-length or full-length audio report. They are ALMOST (but not completely) discriminated out. When a non-ferrous item is added to this carpet of nails and flecks of rust........... NOW........... the audio length in your headphones will be half-length...... or even longer....... audio report. This should be enough to lock up your brakes.... for further investigation. Do not expect the ID to be correct.......... as there are multiple targets under the coil. It will not "ONLY SEE THE NON-FERROUS TARGET" ........... rather............ it will see the composite of all of the targets (ferrous and non-ferrous) underneath the coil....................... and the 'composite' conductivity of all the items underneath the coil will be slightly higher than a discrimination setting of '6'............... causing 'some' audio length to be reported. You can THEN look at the ID............. but............. this will usually get you into trouble............ as most folks look for 'clean' ID numbers............. of which will NEVER happen.......... in carpets of nails.

If your intent is to archaeologically 'relic' hunt (digging absolutely everything out of the ground)............. then.......... the NON-ID mode....... which is the all-metal/auto-tune mode....... is the best choice. If you are pit digging with rare earth magnets.......... the auto-tune/all-metal mode is the best choice.

In terms of the detectors 'audio reports'........... THE BIGGEST DIFFERENCE between:

No discrimination (Disc '0') ID mode................... vs .................... auto-tune/all-metal mode is:

You are given artificial intelligence audio 'beeps' of a PRESET audio length/duration whilst in ID mode.........
whereas
the auto-tune/all-metal mode is unfiltered raw-data raw-audio.

I know I am re-repeating myself with this post........ but maybe I said something slightly differently...... causing a 'trigger'.

Good Finds Cal . . . 1801, the 1906 looks like it was in very dry dirt . . . what kind of depth did you get on these with the SE ?

Yes way to go Cal, I saw that list you posted on Finds of what you've found w the SE.
Where'd you find that gold (dirt, beach?) especially the crucifix? And how did it register?
Thanks

Thank you Tom. I recall you posting about the barber dime you found in the bed of nails, and you reported that you were using monotone, with (IIRC) 0 disc, 99 sensitivity, and BP mode, and the dimes TID was something like 21 or 22. As long as my machine is stable and I don't have EMI to deal with, I've actually been enjoying running 0 disc, 99 sensitivity, 3-tones in BP mode. Even though these old trading post/stage stop/ghost town type sites are loaded with iron (machine gun sounds on every swing) after a while the iron tones to my ears become like a threshold hum, and when it changes, I investigate it.

Next trip I'll try your suggestion to use disc in conjunction with monotone. 90% of the iron was reading '8'. I take it this is the disc setting I should use vs '6' ?

Coincidently 21/22 TID is a good one for a US $1 gold piece, unfortunately it's also a good one for some 22 shells. If limited on time, I have to skip these TID, and I know I run the risk of passing up a gold coin or other keeper.

Thanks,
Brian

mcgov51 Wrote:
-------------------------------------------------------
> Good Finds Cal . . . 1801, the 1906 looks like it
> was in very dry dirt . . . what kind of depth did
> you get on these with the SE ?

These were only about 6" deep, but mixed in with heavy iron.

Aaron Wrote:
-------------------------------------------------------
> Yes way to go Cal, I saw that list you posted on
> Finds of what you've found w the SE.
> Where'd you find that gold (dirt, beach?)
> especially the crucifix? And how did it register?
> Thanks

Aaron it's been a while since finding the gold, so to be honest I can't recall what it came in as. The crucifix was in a tot lot. None was from the beach.

Brian

Brian............... No. If the nails give a VDI reading of '8'........... you may be able to get away with a Disc setting of '5' ...... or maybe even '4'...... in order to discriminate out the iron. The VDI readings vs the Disc settings are divorced. (Not much correlation between the two).

Dig up a single nail. Set it on top of the ground. See what the F75 will ID the nail as. Then..... see how much Disc it takes to disc-out the nail. You will learn ...... the VDI and Disc setting are NOT the same. This is a VERY important thing to know.............. utilize correctly............. and unmask targets with better precise accuracy.

Tom thanks for sharing that, very interesting food for thought!

NASA-Tom,

I still have that testing to do with the Gold Bug Pro and 5" coil...

Having said that...as I read this, it sounds to me like (except for depth capability considerations), I could very effectively accomplish this very same strategy with the Gold Bug Pro in an iron-nail-filled site -- i.e., dig a few of the nails, then start cranking up disc until they are barely discriminated, and then dig all "non discriminated" targets. Since the Gold Bug Pro's audio "break point" is set at the disc level, I would effectively have a "single tone VCO audio" report for any target above the "nail disc." setting. This should, I would think, be very similar to running 1-tone and 6 disc. on an F70/F75, no?

Put another way, I could imagine the possibility -- if targets are NOT as deep as they tend to be in your dirt, but instead fall within the depth range of the Gold Bug Pro -- that it might do just as well as the F70/F75? ASIDE from the depth considerations, is the Gold Bug Pro -- within its depth capabilities -- pretty close to the F70/75, in terms of effectiveness, in this type of scenario (as an "unmasking" machine)?

To take this a bit further, could the Gold Bug Pro even be slightly SUPERIOR in this application (again, within its depth range) -- since in disc mode, the audio (above the disc. point) is modulated, VCO audio (with presumably more intelligence contained therein)? (Plus, not to mention, you'd still get to hear "iron grunts" on the "discriminated" nails, as a possible side benefit, keeping you very "in tune" with the number of targets under the coil)? ASIDE from the depth, is the Gold Bug Pro pretty close to, or could it perhaps even offer some advantages over, the F70/75, in terms of effectiveness, in this type of scenario (as an "unmasking" machine)?

In any case, whether it is "as good as" the F70/75 or not, I assume the concept still applies, that if the nails at a particular site are barely discriminated at, say, "15" on the GB Pro, then, with disc set at 15, anything that gives the higher, VCO audio tone (vs. an iron grunt) would be a target to dig -- even a 16 or 17 ID (which could be a non-ferrous target co-located with a nail)?

Steve

Steve............ that is absolutely correct. I need to add one additional condition/thought. The GB-Pro/G2 run a higher frequency........... so........... they are more hyper-sensitive to iron and lower conductors. Just beware! Also........ their internal clockspeed is the same as the F70/F75/T2..... and the 'same size coils' produce the same footprint. The adjustable tone-break is far superior to any other tone option(s) for this type of hunting scenario (relic hunting in iron infested areas).

((( Note: In general...... higher frequencies are attenuated to greater extent..... especially in mineralized soil ))).

In reference to metal detectors that have adjustable iron discrimination: If you set the iron Disc setting to JUST BARELY discriminate out the 'local conditions' iron...........then............. any audio response that is produced from the metal detector is 'suspect' of a possible non-ferrous co-locate in/amongst the iron............... EVEN IF the ID is still within the iron range! You may have a silver coin that ........ under textbook perfect conditions..... ID's in the 80's or 90's.......... yet, will ID in the high end of the iron range if a nail or two are in close proximity. Just the nails (without the coin) will ID in the --mid or low-- iron ID range............. but ............ with the coin 'in the mix'............ it will now ID in the high end of the iron range.

NASA-Tom

Thanks much for the response; I know of a few locations to try this very thing -- one being an old (1800) church back home in PA that burned, and was re-built. When the original church burned, it appears they scraped the foundation, with nails strewn into the "front yard" of the church resulting in a carpet of square nails.

Your comment about the higher frequency, and thus "hyper sensitivity" to low conductors is duly noted...

I will attempt to use this "unmasking" knowledge to my advantage, and I thank you for the "education" regarding this concept!

Steve

Saving you time............ making you more 'efficient' is grounds for creating:

more fun
more finds
more time
more happiness
more 'awareness'
more discoveries
accelerated learning-curve
higher educational plateau

etc............

Sometimes it takes several readings and deep concentration (with no distractions) to come to a full understanding of what Tom is trying to get across.... at least for me.

Speaking of the Monotone Method with Nails Disced Out (f-70/f-75), most detectorists don't know this method of unmasking. For one, it's a slow swing slow going hunt. If you leave out one step in the procedure, you won't get the results intended.

The digital bells and do-dad units get us focused on a dozen other things other than the audio tool. I have noticed when using the cz (or any other audio unit), it helps me to be more of a tone/sound hunter. So, when going back to my f-75, those learned skills go along. This helps me with this method of unmasking, as the cz kind of weans me from relying on the VDI numbers.

One mistake I was guilty of, was hearing the tone (mono), and if the VDI numbers weren't up in the coin range, I passed it up. That right there will blow it. That alone took awhile to sink in....finally,, it clicked.

This method that Tom has discovered, is like not having the right tool for the job, but figuring out a way to do it with the tools available. The end results are the same and I applaud that ingenuity.

ozzie -- I agree...he puts so much info in so few words, that there are multiple little nuggets in there that you have to really think about.

NASA-Tom --

From a practical perspective...I have been pondering this since this morning, this "unmasking," and my Gold Bug Pro. This all sounds easy, from a "laboratory" perspective, but, of course, it's not. In the field, the nails are obviously not "homogenous;" many are bent, all different sizes, etc. etc., each giving a different ID number (and thus requiring different levels of disc. to eliminate). Along those lines, I can imagine where if I chose to disc. out the HIGHER reading (larger, or bent) nails, I may STILL miss some non-ferrous targets juxtaposed with lower-reading nails (whose composite ID, then, might still fall below the "bent nail" disc. level, and thus be disced out); consequently, if I disc out only the lower reading nails, I'm going to dig a boatload of higher-reading ones (unless I can really learn to "coax" more info out of the audio or something). So, practically speaking, if you were hitting a site like I described above (old church yard, with a bed of square nails in the front yard due to a previous fire), would you disc. out the HIGHER reading nails, the LOWER reading nails, or something in between? This is assuming you can't work the site to death, but only have one or two hunts to try and pick out a few keepers...

Are there actually cases where a coin/nail together would actually ID just two or three points above the "just nail" ID? Or, would such a target juxtaposition normally ID several digits, or even tens of digits, higher (though still way, way below coin range)? Having said all this, I suspect one should not focus on the digital ID at all; I presume you are listening to the TYPE of tone, for the dig/no dig decision? You were talking about "crackles," "half tones" and "full tones" above, which suggests to me that ANY target which reports gets your interest when using this method, and that you then are listening to the AUDIO to get your clue to dig or not. I assume, then, especially with the GB Pro's modulated VCO audio, that one eventually could/would learn to pick up even MORE clues in the audio as to making a dig/no dig decision?

Steve

steveg Wrote:
-------------------------------------------------------
>This all sounds
> easy, from a "laboratory" perspective, but, of
> course, it's not. In the field, the nails are
> obviously not "homogenous;" many are bent, all
> different sizes, etc. etc., each giving a
> different ID number (and thus requiring different
> levels of disc. to eliminate).

I was thinking the same thing after reading Tom's post. I do notice when hunting these iron infested sites, that, for me at least, the iron tends to average about 8 on the TID. I twill be interesting to dig some of these signals, and see what the disc # is to silence them. I hope that I can keep it under the 6 so as to keep the extra sensitivity

Brian

Brian = VERY good........... and very correct in your thought process.

Steve = You are also very correct in your thought process. Where you set your Disc is a judgement call. Local site conditions, allowed/authorized hunting time available for that specific site.............. and ................ your skill-set (including fatigue factor) will dictate what collective capabilities will allow you to do.

You are correct in your thinking that there may be a plethora of different 'types' of iron in the ground......... subsequently..... each one having a different iron ID. So............ where do you set Disc? Interestingly........... you will find the bulk of the various iron targets in the ground will Disc out at a setting of '6'.......... in nearly all cases. If you start hunting a specific property.......... one of the ways to 'efficientize' your efforts is to start with a Disc setting of '6'............ and see how quiet or how noisy the detector responds. Then...... bounce this performance with: 'can I handle this with productive success'. If the detector is too quiet........ you can drop Disc to '5'............. and check out your fatigue factor again. And........ just as Brian brought up........... if the detector is still quite quiet...... you can drop Disc to '4' (which is also a Sensitivity boost point)......... and see if you can handle the detectors audio.... with the local site conditions. There IS a learning curve to this! Yes......... nearly all hunting is performed by audio responses......... with nearly nothing going into VDI readings. Once a target of 'question' is found............ then rotating your body around the target to find its best acquisition point........ THEN maybe you can look at the VDI reading as a distant secondary input.......... AFTER you have already decided to dig/no-dig.

A couple of weeks ago...... I hunted a site whereby..... there were primarily only one-type/one-conductivity of iron targets in the ground. A very old homesite where the house either burned down (suspected..... as some charred wood was infrequently being recovered)....... or the house was bulldozed down decades ago. Over 99% of the iron targets in the ground were one type of nail. I was capable of getting away with a Disc setting of '2'........... causing nearly all of the iron nails/targets to be discriminated out (just barely). Yes.... a lower Disc setting (if conditions allow) presents for even greater iron see-thru. Yes, (to answer another question of yours)......... there were plenty of non-ferrous targets that were so badly masked by the iron.......... that a slightly higher Disc setting would NOT have allowed a audio report to eminate on these badly masked non-ferrous targets.

How badly masked a non-ferrous target is............ is dictated by:

1) How close the non-ferrous target is to iron
2) How big is the ferrous/masking culpret
3) Is the non-ferrous target 'beneath' the ferrous item (3-dimensional 'Z' coordinate)
4) Is there more than one ferrous target that is masking the non-ferrous target
........... and a few other determining factors.

This thread should have been posted/included in the Rcpt Ack of F75 LTD prototype thread........ so as to keep it all together.



Edited 1 time(s). Last edit at 03/21/2012 10:57AM by NASA-Tom.

NASA-Tom -- thanks for the thorough, thoughtful, most-informative answer. Makes complete sense, and answers all my thoughts/questions.

Now, I simply need to learn that disc. point as it pertains to the GB Pro -- that is roughly equivalent to that "6" level on the F-75...some testing is in order...

Steve

On the T2SE, is this unit and the F75SE close enough in likeness to do the same type of unmasking technique with it? I am about to make a ne thread on the T2SE asking for corresponding numbers with the F75SE.

Tom, could we make the Rcpt Ack of F75 LTD prototype threads a sticky to stay at the top of the forum ?

Something I've always been impressed with on the F75 LTD, is that I dig darn near zero iron, unless I'm digging the really deep, iffy, fringe stuff, and then I know I'm rolling the dice (to be honest, this has NEVER paid off for me, yet at target sparse sites, desperation pushes this behavior

Another iron releated impression I've noted - The F75 is so good in iron, that when I dig a hole in an iron infested site, it's not uncommon to initially recover a nail or two, and initially jump to the conclusion that the F75 falsed on the nails, and you got fooled. BUT, most of the time, if I keep checking the hole, almost without fail there's a non-ferrous target in the hole just as the detector reported.

Kevin.............. yes, the same principle-of-physics (in reference to unmasking) applies to the T2; however......... the Disc settings are a bit different.

Brian.............. No, Yes, YES.

For now.......... web-master desires not to make sticky's....... out of a few threads. (Yet).