Interesting hunt

Fred and I went to an old plantation today and I can honestly say I've got a bad case of the puzzles.
Fred hunted with the Manticore as usual and I took both the F75 with the 5" DD coil and the Equinox with the Coiltek 10x5. I started hunting with the F75 and within 30 minutes I had dug not one but two wheat pennies, a 1918 and a 1954. I was using the 5" coil, 3 tones, sens at 88, discrimination at 0. Both of these pennies gave a very good 4 way audio. Really couldn't believe it because both the Equinox and Manticore had hunted tirelessly in this area and I was sure it was hunted out. Well anyway, as a test I decided to bury a clad dime in the same area where one of the pennies was at. Nice area at 8" deep and compacted to dirt good and tried the F75 and no issues as long as the coil was directly over the dime, but.
Neither the Manticore or Equinox would give a good enough audio to prompt us to dig. The ID on both detectors had been pulled down well over half of what a dime should indicate. Fred was doubting that a dime was there so we dug it up and then reburied it at 6.5" deep and still the F75 had no problem but both other detectors failed miserably. Spent a lot of time after this pondering the occurrence. I know what is going on but also understand the 5" coil is the ticket to successfully recover at this location. The ground at this site comes alive with low volume iron grunts. One more thing I would like to add is that turning up the sensitivity at this site degrades the audio to an extent almost nothing can be found.
In addition to this the coil needs to be scrubbing the ground. The only other site that exhibits the same type anomalies is one of the old schools where the waste, from coal burning furnaces have been discarded on the school grounds for decades. Not me but Tom, "you don't know what you're missing if you don't know it's there" Well or something like that

Mark,

What a really, really strange occurrence. I wonder if the EQX & Manticore would have done MUCH better with the smaller coil?...... because it sounds like your location is heavily covered with nails (and possibly mineralization). I would have instantly tried several other/differing settings.... until resolve. Yes....... you can revert back to F75 performance/Operating-System... with EQX & Manticore...... by switching to Single Frequency. (( Either 10-KHz or 15-KHz would be first choice )). , . , . , . , . yet; I do not think that reverting to a Single Frequency would be the answer.......,,,,,,,but would use it as a last resort. For EQX & Manticore to NOT be able to detect a 6.5" deep Dime.............. would instantly prompt investigation and probable cause!!!

In my opinion, it can be iron and maybe plus conductive terrain.../where the ID of the coin drops/and where the small coil can play a very important role....it is very similar to the mechanism of the 2D separation test of the Monte performance nailboard Test-, or My "iron carpet" test, where the small coil always gives better results because it sees a significantly smaller part of such extra difficult terrain...
[www.youtube.com]

Alternatively, I would try to change the programs that will work better in conductive terrain with Equinox and Manticore

Only a really small coil in a certain terrain can achieve reasonably good results.



Edited 2 time(s). Last edit at 02/07/2024 02:03PM by EL NINO.

Yes....... Mark may have 'cleaned out' all of the coins that are Stock Coil (11" coil) detectable.
Then..... there will be a group of coins that will ONLY be detectable to ONLY a different configuration/size coil.

((( This is also to say: The EQX and Manticore 11" coils WILL detect some coins....that the F75 5" coil will NOT detect. )))

I might add a little more information to my original post. Most of the holes I dig at this site will cause my F-Pulse pin pointer to continuously give a response at the bottom of the hole, which leads me to believe there is or possibly might be a large amount of rusted "decayed" nails in the area. I have dug several square nails that are 1/2 way decayed which would cause the decayed rust particles to leach out into the surrounding soil. Any rust particles will cause all kinds of issues with my detectors.
Now I will say, Fred has traded his CTX 3030 for a new Deus2 which will be here Saturday. We'll see how the comparisons go forth.

Okay! HIGH iron-oxide volume ..... is the cause!

Yes...... the Deus-2 will see (yet) ANOTHER batch of targets that other units have missed! (((Plus......by virtue of digging "iffy" targets....... you will inevitably find a few more 'keepers' )))!!!!

I have an opportunity to trade my Equinox 800 in for a new detector. Very fair trade in value I believe. Well, anyway I was considering the Equinox 900 since I also have the 10x5 that works on the 800 and can use on the 900. What advantages will I have with the 900 over the 800 or should I think about upgrading to a more expensive machine. The Equinox 900 package comes with the 11" stock coil and the 6" DD coil too.

I would still recommend the Manticore........ with M11 & M8 coils.
BUT...... if your dirt is hot.,.,.,.,., then still the Tarsacci.

NASA-Tom Wrote:
-------------------------------------------------------
> Okay! HIGH iron-oxide volume ..... is the cause!
>
> Yes...... the Deus-2 will see (yet) ANOTHER batch
> of targets that other units have missed!
> (((Plus......by virtue of digging "iffy"
> targets....... you will inevitably find a few more
> 'keepers' )))!!!!

Thanks Tom, that was the exact answer I was looking for. I believe there is an older layer below where we have been finding stuff, since there has only been 2 items found that would come close to dating the location. Maybe just 4-5" deeper where the iron-oxide layers are. At the present time the F75 with the 5" coil might be my best option.

And Tom, I sent you a message

I had such high hopes for the Tarsacci, but EMI all but completely shutdown the detector. I actually planned on selling my White's TDI to buy the Tarsacci if it performed equal to or better than the TDI.

Some of my areas are on the extreme side of ground conditions. Between the small coke waste to iron-oxide, most detectors are completely crippled below 4" deep.
Oh well.

Tom, I believe your analysis of my anomalies is spot on.
The F75 is the way to go at this site for sure, unless we can figure out the upper and lower ferrous limits on the Manticore.

Having the ability to adjust Ferrous Limits = Upper & Lower..... allows/authorizes you to adjust to exacting conditions of a specific site. . . . . . ultimately allowing for much better unmasking. There may be multiple DIFFERENT TYPES of 'ferrous offenders' at a specific site. Adjusting Upper and Lower to compensate for the differing offenders (at a level that is intelligible to you)........ is KEY to success.....,,,,,,,.......and.......... after a bit of practice.,.,.,., can become a fairly easy/learned skillset.

As of the moment....... right now.......,,,,,,,,, it sounds like the (almost) 13-KHZ single frequency of the F75........coupled with the small coil......(so far).......is the best performer.

Does adjusting the upper and lower limits also affect the all metal mode or just the discrimination mode?

Gosh. Let me premise with this: If I do NOT explain this to a good level of understanding......LET ME KNOW!!!
(((Here goes))) =

On a TRUE All Metal Mode........ ANY piece of metal....... makes the metal detector go: "BEEP". On 'some' detectors......... the VDI still works.......giving ONLY a 'visual' ID of the target......,,,,,,,,........ in a true All Metal Mode; yet, you still get a ZERO VARYING TONES ((no 'tone' ID)): "beep". Absolutely zero items (targets) are discriminated/notched out.... in a true All Metal Mode.

On Manticore.,.,.,.,., if you are in a Park Mode, a Beach Mode......a Field Mode.......,,,,,,,,,,,...............,,,,,,,,,,,,,,,,,................. these are all ID Modes. NOT to be confused with "All Metal" Mode.......by definition. Yes...... in these Modes..... you can "bring in" all metals. , . , . , . , and all metal targets will be assigned a 'tone' for ID purposes. , . , . , . but/yet....... this does not constitute "ALL METAL" Mode........ by definition. They are still: ID Modes.

So. What does this have to do with: Ferrous Limits = Upper. And: Ferrous Limits = Lower?
On Manticore...... you MUST be in a ID Mode.....in order to employ Upper & Lower Ferrous Limits.

First......... let's talk about 'iron'.
Different iron items WILL have different ID's. JUST LIKE NON-FERROUS!!! A silver coin...... has a dramatically different conductivity then compared to a Nickel. , . , . , . , . , . , . , . and .... you will get a different ID for a silver coin...... as compared to the Nickel.
SAME WITH IRON! A rusty nail will have a certain ID. A piece of barbed-wire fence....will have a DIFFERENT ID as compared to a rusty nail. A steel fish hook will have yet ANOTHER different ID ...... as compared to a rusty nail. A iron boot-tack has IT'S own differing ID. A rusty bobby-pin has a certain unique ID. All iron implements have different ID's.

Adjustable iron Discrimination can do WONDERS....... in the world of unmasking.
If you are hunting a nail-infested site with Manticore.........................where there are tons of nails; yet,.......... there are no steel fish hooks, no steel bobby-pins...... no rusty barbed-wire fence pieces . , . , . , . , . , . , . , . , . , . , . , . , . it may be VERY advantageous to 'push-the-limits' deeper into the iron Discrimination via Upper & Lower Ferrous Limits.

There is a huge write-up/explanation in the old (huge) Fisher F75 thread ...on this forum.........about hair-splitting iron Discrimination uses.,.,.,.,. to include High Resolution Iron Discrimination.

Let me give just one example:
Let's say...... the site you are hunting.,.,.,., most of the iron (rusty nails) ID in the ID range of -47 to -38. (Read = Negative 47 to Negative 38). Remember..... iron/ferrous ID's in the Negative numbers range.
Now let's say you have a silver dime at 8" deep....... and a rusty nail over top of the silver dime ...at 7" deep. (((Nail and Dime on top of each other.,.,.,.,., one at 7" deep......and the other at 8" deep))). The Manticore may ID this composite nail+coin combination as -17.
You say: WAIT!!!! Almost all nails ID around -45... at this site. What could possibly ID as high as -17??? Hmmmmmmmmmmm.
So..................... you adjust Ferrous Limits = Upper (on your Manticore) from a factory conservative 'safe' setting of 9........ down to 4....(which is aggressive as perdition!).
NOW targets that ID (say) -30 (read = Negative 30)....... and above .....,,,,,,...... will NOW ID somewhere in the non-ferrous tone range!
And now.............. you just recovered a silver Barber Dime .....underneath a nail !!!
Was the audio signal: a nice textbook-perfect "coin tone"? Nope!!!! Not at all. BUT....... you just unmasked a non-ferrous target....... in a carpet of nails...................that.....................never in the history of mankind.................has been performed before.
NASA-Tom

Out-of-time!

Hmmmmmmmmmm. Can someone cut/paste this to the Manticore thread? It belongs there also.