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ON THE HORIZON = MDT-8000

Posted by NASA-Tom 
JCR
Re: ON THE HORIZON = MDT-8000
March 17, 2022 02:38PM
I think this shows Dimitar is working on suggested improvements for the next itineration of MDT. The tones needing more separation was one of the things I had spoken to him about. I also think the next generation will allow for updates & optimizing for individual hunting conditions.

Chris
Re: ON THE HORIZON = MDT-8000
March 17, 2022 11:12PM
NASA-Tom -- understood; yes, it "is what it is!" You are just the messenger, and I appreciate you getting the information.

Chris -- I would sure hope that the tones would be "adjustable" on future units. User-selectable frequencies, and the ability to change the "bins" into which various ID numbers are assigned to which tones, would be a great improvement in that aspect. The ergonomic improvements that I feel are necessary, would be the other thing that I'd most like to have changed...

Steve
Re: ON THE HORIZON = MDT-8000
March 18, 2022 01:23AM
More data/analysis:

The 11" x 8" coil presents approx 17% greater adjacent target separation (in the real World)....... over the round 12" DD coil. This is formidable. Example: If you dug 100 coins in a fairly trashy area with the 12" coil....... you could expect to find 17 more coins with the 11" x 8" coil.
By way of comparison: the Equinox ascertains approx 11% greater adjacent target separation with the 6" DD coil........ over the standard/stock 11" DD coil.
This may seem non-linear/disproportionate; yet, remember..... the electronics (Operating System) is a major player in this determinant.

Another interesting observation: On two of my targets today..... (both turned out to be copper coins...... both early Wheats).....as I speculated BEFORE digging ((hence: "WHY" I choose to do a head-to-head on these two specific targets))............. I observed the following:
F75 LTD presented a VERY washed-out high-tone..... about 70% of the time on the 5" deep penny (remainder 30% of time...... ID was: Iron)......,,,,,,,........and 30% of the time on the 6.5" deep penny....with 70% Iron ID's). A definite: NO DIG.
The Tarsacci presented a very sharp/distinct non-ferrous tone.....with zero indication of 'iron washout' audio.
Reason: MANY blood-spots///rust-flakes between coil and coin. The Tarsacci 'timed-out' the rust flakes and gave a clear signal; while....the F75 took ALL of the metallic implements into the algebraic algorithms........and 'averaged' the composite.
JCR
Re: ON THE HORIZON = MDT-8000
March 18, 2022 01:39AM
NASA Tom What Salt Balance & frequency were you running on the Tarsacci when you made this comparison?

Chris
Re: ON THE HORIZON = MDT-8000
March 18, 2022 11:34AM
6.4-KHz (which is the least sensitive to iron).
Salt Balance: 48
Ground Balance: 993
Black Sand: OFF
JCR
Re: ON THE HORIZON = MDT-8000
March 18, 2022 01:02PM
Thanks.
Is this on your same site across the road from the church? I see you have increased your GB # from your experimenting @ 750-800.

Chris
Re: ON THE HORIZON = MDT-8000
March 18, 2022 02:18PM
Yes. Same site.

I'm experimenting with Ground Balance a bit.,.,.,.,.,. attempting two things:
1. Less iron falsing
2. Slightly better iron see-thru.
JCR
Re: ON THE HORIZON = MDT-8000
March 18, 2022 02:44PM
Are you seeing a correlation between relative GB & SB settings? In my high mineral sites, the higher the GB the lower the required SB. You can run Salt up with no obvious ill effects in you choose to. If you re-GB with the higher Salt setting you will get a lower GB # than initially. I am still trying to find the optimal range. Add iron/nails & it is even more interesting. Mild mineral sites seem to be more forgiving.

Chris
Re: ON THE HORIZON = MDT-8000
March 19, 2022 02:09AM
JCR -- yes, agree, mild sites must be more forgiving. If I ran ground balance "away from" the optimal settings, my dirt causes a ton of ground noise on the MDT...

Very interesting stuff, NASA-Tom...

Steve
Re: ON THE HORIZON = MDT-8000
March 19, 2022 03:03AM
Because I have low/no minerals in my dirt......... I merely use the Ground Balance for mitigating iron falses. Certainly NOT for mineralization!
High Salt Balance numbers will desensitize the unit to small chewing gum foil..... and small pieces of aluminum can slaw.

I use Salt Balance & Ground Balance in unconventional (and unsuspecting) ways........ whilst dirt hunting.
JCR
Re: ON THE HORIZON = MDT-8000
March 19, 2022 07:11AM
So is rust & small disintegrating iron desensitized at lower Salt balance settings than foil & small AL? I don't think the SB is linier like a Disc control.

Chris
Re: ON THE HORIZON = MDT-8000
March 19, 2022 12:40PM
Chris......... THAT one I don't have an answer to. These things I'm still on the 'discovery' phase.

There's also quite a few other setup/config combinations that I want/need to experiment with......... in a controlled environment/test(s).
Re: ON THE HORIZON = MDT-8000
March 19, 2022 02:12PM
So how do you determine your best GB...... turn SB OFF then set it first? Is it like raw gold hunting where you hunt just below GB.... which means you hear more minerals as well? Ive not dirt hunted in years since i moved to Fl.
JCR
Re: ON THE HORIZON = MDT-8000
March 19, 2022 07:41PM
For now, on my high mineral sites without a lot of small iron, I GB with Salt off or on a low number, then set my Salt balance, then do a final re- GB with that SB setting. This allows me to monitor the ground feedback in Mixed mode & re GB if needed. Most of my sites are or were forested in the past & the ground seems to change some as you hunt, just enough to notice. I suspect the old decayed root balls are the reason.
On my high mineral sites With a lot of small Iron I will go ahead and activate the SB @ a high number(45-50) and Ground balance from there. I need to further experiment with mid range(25-35) numbers in the Iron polluted sites.
On Low mineral sites I have had success with NASA Tom's GB 800-850, SB 45-50 in & out of Iron trash.

Chris
Re: ON THE HORIZON = MDT-8000
April 10, 2022 01:43PM
More data for the record:

Although there is a formidable loss in depth on high-conductors whilst on 18-KHz with the Tarsacci......... there are employable attributes. 18-KHz presents more rapid (clocking) enhanced adjacent target separation characteristics. Very beneficial for heavy-trashy areas. If you are unable to go much deeper than (say) 5" - 7" anyway....... due to high trash content..............than 18-KHz can be a major attribute. If trash content is low........then the extra depth gained from using 6.4-KHz would be the better choice.....for high-conductors.
Also....... in the World of physics..... higher freq's mean: greater sensitivity to smaller targets, greater sensitivity to lower-conductor targets, higher sensitivity to small rust flakes/flecks.........and greater signal/energy attenuation......especially in mineralized dirt. Unlike VLF and SMF platforms........ the Tarsacci is much less susceptible to signal/energy attenuation in bad dirt.......... and (again, unlike VLF or SMF units)........ the Tarsacci retains the ability to NOT see (they're timed-out) small rust flecks/flakes whilst on 18-KHz. If you are in a heavily trashed-out area........ you can put this to good use.
Wisely use the Salt Mode (and the separate Ground Balance Mode) to your advantage.........(yes; in an unconventional way).
Re: ON THE HORIZON = MDT-8000
April 15, 2022 02:37PM
I fell flat-on-my-face yesterday..... with the Tarsacci. I took the Tarsacci 'Discrete Conductivity' hunting. I went to a old 1902 High School...... to hunt for specifically/exclusively Nickels. In the 1920's, 30's and 40's....... your school lunch cost a Nickel. If you lost your Nickel........ you lost your lunch. And THIS is 'Why' older schools have a uncanny high-level of Nickels in the dirt.
On the Tarsacci....... Nickels ID around the '06' range. All high-conductor targets had already been hunted/removed. Sooooo......... only the Nickels remain. 18-KHz on the Tarsacci presents maximum depth/performance on Nickels. -------After 5-1/2 hours of hunting..... I had zero Nickels. I had a excessively large pocketful of trash. Chewing gum foil was ID'ing around 06. Aluminum can-slaw ID'd around 06. Small slivers of lead ID around 06. Lead BB's ID around 06. Melted pieces of aluminum ID around 06. Etc. etc..............................
Very frustrating.
BUT!
Lessons learned:

((({{{ It is IMPORTANT to know your capabilities........... as it is: EQUALLY IMPORTANT to know your limitations!!! )))}}}

Because the Operating System of the Tarsacci is not SMF/VLF (rather; time-domain primary)............ the ID system is more crude.
Moral of the story /// Summational observed resultant:

The Tarsacci is superior for bad dirt. The Tarsacci is superior for delineation between ferrous........vs.........non-ferrous. The Tarsacci is superior for wet-salt (with....or without black sand)......... on the beach.,.,.,.,., and especially IN the saltwater. The Tarsacci is a superior relic hunter.The Tarsacci is terrible for Discrete Conductivity hunting.
Use the Tarsacci for any/all of the above applications. Use a good SMF/FBS/FMF/VLF for Discrete Conductivity hunting.
It is very important to be very clear about what the Tarsacci IS good for. And what the Tarsacci is NOT good for! ((Results in: less frustration........and better end-resultant)). Face the facts.
Re: ON THE HORIZON = MDT-8000
April 15, 2022 03:49PM
Thanks for all you info Tom. Love reading your posts
JCR
Re: ON THE HORIZON = MDT-8000
April 15, 2022 05:21PM
NASA Tom, Aside from the modern trash, what is the soil like at that site? Is it very mineralized? Mild?

Chris
Re: ON THE HORIZON = MDT-8000
April 15, 2022 06:59PM
Chris........... it is mild soil......with a fair amount of decomposed rust flakes/flecks.
Re: ON THE HORIZON = MDT-8000
April 15, 2022 11:30PM
NASA-Tom,

Thanks for the post. Your observations match mine. When I tried "discrete conductivity hunting," but in the silver range, instead of the nickel range, similar problems ensued, to the point that I was forced to reach the same conclusions that you did.

The machine has a number of strengths, and will excel in a number of applications. "Cherry-picking" coins, in trashy, junk-filled turf-type scenarios is NOT one of them. You used the word "terrible," for this application, and I'd second that description.

THANKS! Glad I'm not "crazy..."

Steve
Re: ON THE HORIZON = MDT-8000
April 16, 2022 04:30PM
I ended up getting a MDT with 12 inch coil that came yesterday. I would like a new pair of headphones for it though; does anybody know where I might find a set?

It took me a minute to remember how to adjust settings but once I figured it out, this machine smokes everything in my test garden. Everything. This machine with the 12 inch coil is going to be a depth monster.
Re: ON THE HORIZON = MDT-8000
April 16, 2022 05:18PM
Daniel Tn Wrote:
-------------------------------------------------------
> I ended up getting a MDT with 12 inch coil that ca
> me yesterday. I would like a new pair of headphone
> s for it though; does anybody know where I might f
> ind a set?
>
> It took me a minute to remember how to adjust sett
> ings but once I figured it out, this machine smoke
> s everything in my test garden. Everything. This m
> achine with the 12 inch coil is going to be a dept
> h monster.

I had Tony E make me jumper cables to use my favorite phones.
JCR
Re: ON THE HORIZON = MDT-8000
April 16, 2022 09:26PM
Daniel, If you got the HP dongel 1/8" adapter you should be able to do whatever you want. Mine sure sounds better thru KillerBs than the supplied HPs. Look forward to your reports on it in your dirt.

Chris
Re: ON THE HORIZON = MDT-8000
April 17, 2022 01:37AM
I've had quite a few folks really like the KOSS QZ99 headphones on the MDT. This is what I use.

Steve....... Nickel hunting with the MDT is no fun.,.,.,.,.,.,., but hunting (cherry-picking) for silver dimes (or higher conductors) is a dream with the Tarsacci. , . , . , . , . , . , . , . which makes me wonder if YOUR dirt is doing something different. The MDT will find modern copper pennies..... silver dimes...... with tremendous success.,.,.,.,.,.,. even in nail-infested sites.

Daniel....... if you are a relic hunter....... the Tarsacci (with 12" coil) "should" be a dream............ once a bit of a learning-curve is acquired. (((And that 12" coil really wakes-up the Tarsacci........especially in the department of depth))). Did you go through Dimitar to get your Tarsacci? If so........ keep him in your back pocket!
Re: ON THE HORIZON = MDT-8000
April 17, 2022 02:19AM
NASA-Tom,

It MUST be the dirt. I can't tell you the number of beaver tails that I dug, that gave the same tone/VDI behavior as a deep copper or silver coin, and meanwhile one of the deepest coins I dug in the wild, which ALSO gave that same type of silver/copper coin reading, was a 1940s Jefferson nickel...

I find this odd, that you are having such success with a "bad dirt" machine, in mild dirt, and yet in my "bad dirt," where the machine should excel, it's the opposite of your experience...

Now, with that said, when I say "the opposite," I'm again talking "ID." Max depth with the Tarsacci in my dirt is greater, as I've noted before, than any other machine I've hunted here. But the tones and ID are entirely inaccurate, with respect to trying to "cherry-pick," in Oklahoma dirt.

Steve



Edited 2 time(s). Last edit at 04/17/2022 02:24AM by steveg.
Re: ON THE HORIZON = MDT-8000
April 17, 2022 12:17PM
Steve.......... in your Oklahoma dirt (your conditions)............ is iron 'mostly' ID'ing in the iron range........................ and non-ferrous ID'ing 'mostly' in the non-ferrous ID range (albeit: inaccurately.... anywhere in the non-ferrous ID range)?
Re: ON THE HORIZON = MDT-8000
April 17, 2022 03:41PM
NASA-Tom -- yes. That's correct. Iron IDs consistently "as iron," with the caveat that a good bit of iron (flat iron, etc.) will ID solidly in the high conductive range (wrap-around) -- consistent high tone every sweep, and consistent upper 20s numbers.

I will note that the iron targets that "high-tone" (i.e. consistent high tone, and consistent high 20s ID) are very UN-LIKE any non-ferrous high conductors I have dug with the unit -- so it makes it rather easy to recognize that it's iron wrap-around (and so, I consider this to be "IDing as iron" -- even though "technically" it's not...) Meanwhile, ID numbers given off by a non-ferrous high-conductive target come in well below these "high 20s" iron targets; instead, high conductive non-ferrous targets are essentially always a mix of mid and high tone, and a random mix of ID numbers BELOW high 20s (generally single digits to low 20s). The reason I said ESSENTIALLY always, is that there is an execption. The exception is that the machine is "accurate" across the VDI scale (appropriate tone, and an ID that only wavers a digit or two from "air test" value) on any target, to a depth of about 2" to 3" deep (roughly). Beyond 3" deep, ID rapidly/entirely breaks down.

Steve



Edited 4 time(s). Last edit at 04/17/2022 10:46PM by steveg.
JCR
Re: ON THE HORIZON = MDT-8000
April 17, 2022 07:19PM
I have found in my heavy iron based red dirt that Black Sand On will help correct the VDI but at the cost of fringe depth of smaller targets. Since I use the MDT as a relic machine I go by tone almost exclusively. If it isn't a nail I usually dig it. Yes, big iron is easy to tell.

Chris
Re: ON THE HORIZON = MDT-8000
April 18, 2022 02:24AM
Steve...... ok. Awesome! This is a GOOD START for trying to figure out your dirt AND the MDT in this situation.
YES Chris!!!......... = Steve....... if you can......... try Salt Mode ON..... with it in the 45-to-50 range......... AND invoke Black Sand "ON"....... and see if there is a better ID resolve. ((({{{ I hate to put you through test-after-test-after-test.....after!!!!...... = yet, if it can truly help you in your dirt........ it may still be a Godsend )))}}}.
Re: ON THE HORIZON = MDT-8000
April 18, 2022 11:46AM
JCR Wrote:
-------------------------------------------------------
> Daniel, If you got the HP dongel 1/8" adapter yo
> u should be able to do whatever you want. Mine sur
> e sounds better thru KillerBs than the supplied HP
> s. Look forward to your reports on it in your dirt
> .


Where can you pick up the dongel?

Thanks.
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