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ON THE HORIZON = MDT-8000

Posted by NASA-Tom 
Re: ON THE HORIZON = MDT-8000
February 26, 2022 03:04AM
This is good stuff, JCR and NASA-Tom. THANK YOU for sharing. Very good info...

Steve
Re: ON THE HORIZON = MDT-8000
February 26, 2022 04:04PM
I only wished I knew if 18-KHz is better than 9-KHz (or 6-KHz) in mineralized dirt. In most cases...... higher freq's are attenuated at a much greater rate...over lower freq's; yet, the Tarsacci's operating system is quite different; hence, all bets are off.
JCR
Re: ON THE HORIZON = MDT-8000
February 26, 2022 05:32PM
I have found all the available frequencies work well but, have their own subtle characteristics. I have not learned these enough to even be able to define them. Dimitar recommend 12 kHz for red dirt. I most often use 6.4 kHz for some reason. It seems smoother. 18 kHz seems friskier & it's audio is higher pitched & tighter.
NASA Tom, have you investigated getting some mineralized soil trucked in from a dirt contractor/landscaping company to build a dedicated test bed?

Chris
Re: ON THE HORIZON = MDT-8000
February 27, 2022 02:07PM
Chris....... yes. I have actually thought about building a small wet-salt beach....... and a Georgia red clay test-garden.......at my abode. But....... too much logistics involved!
JCR
Re: ON THE HORIZON = MDT-8000
February 27, 2022 05:11PM
Even half of a cubic yard of each in a container box like palzynski uses would be functional.

Chris
Re: ON THE HORIZON = MDT-8000
March 01, 2022 03:54AM
Another thought/observation of mine.......regarding the Tarsacci........ that I should share:

6.4-KHz

Low frequency is a low performer on low conductors.
(You think this is a detriment? Go hunt an old site loaded with modern aluminum can-slaw trash & foil........ looking for coins)!
Re: ON THE HORIZON = MDT-8000
March 03, 2022 12:05AM
More documenting and 'putting-things-into-perspective:

Tarsacci with 12" coil on 18-KHz, Salt Balance '18', Thresh '0', Black Sand 'OFF' on a saltwater wet-sand beach:

Sens '3' = Will not detect a 14" or 15" deep Nickel
Sens '4' = Will detect a 14" & 15" deep Nickel.....coil must be on the ground.,.,.,.,., no air-gap forgiveness.
Sens '6' = Will detect a 14" & 15" deep Nickel...... and with approx 3" additional air-gap over the 15" deep Nickel.

My Nickels are (2-part epoxied) onto Schedule-40, 1/2 ID PVC sticks that measure exactly 14" and 15" in length. Today...... I had the 2 PVC sticks about 3-1/2 feet apart from each other....... so I could make a single coil sweep.....that would pass over both of the Nickels (for comparison/signal-strength analysis).
I tested 2 Tarsacci's (Ser# 00017 & 00302). The only difference between the two were...... one of them (#00017) was on a Ground Balance of 990. The other Tarsacci (#00302) was on Grnd Bal of 580. (I use Ground Balance in an unconventional way.......since Florida beaches have no minerals --only alkali-- .......sooooooo.......... Ground Balance is merely used for finding 'enhanced stability'; yet, does not affect depth). Both units presented nearly the exact same (14" & 15" deep Nickels) performance.
Re: ON THE HORIZON = MDT-8000
March 03, 2022 06:09PM
NASA-Tom,

Very interesting testing results, and ESPECIALLY interesting, considering that sensitivity is the "weaker" adjustment, in terms of performance, whereas threshold is the "greater" adjustment, per earlier posts. What this says to me, is that the settings on this machine are very important to understand, and to "get right," to the greatest degree possible, if you wish for maximum performance on a given day/at a given site.

Very informative...

Thank you!

Steve
cdv
Re: ON THE HORIZON = MDT-8000
March 03, 2022 08:50PM
Nasa Tom

Ditto what Steve just said!

"Tarsacci with 12" coil on 18-KHz, Salt Balance '18', Thresh '0', Black Sand 'OFF' on a saltwater wet-sand beach"

Exactly the settings I have been using on the wet sand with good results HOWEVER, I would never have thought about lower sensitivity settings still reaching those depths. Next time out, I'll be doing some extra testing on found deep targets just to see.

I'm assuming here that lower sensitivity picking up the deep nickel could/should eliminate some of the shallower trash aluminum???

Cliff
Re: ON THE HORIZON = MDT-8000
March 05, 2022 09:02PM
So, I ventured out to an old park yesterday, with the MDT 8000. This was the first time I braved moving out of the confines of the "safety" of my test garden, and the "relative safety" of a small section of a local park that I know like the back of my hand. As noted in a prior post, because I know this small section of my local park so well, and know what targets are in the ground in this section (very few), it made moving out of the test garden and into that spot only marginally more difficult, in terms of learning the machine. As noted in that earlier post, knowing that any decent target left in that spot would be deep, and potentially an old coin, it allowed me to focus on any high-tone whispers, where the only issue would be trying to discern whether the target was likely iron (a no-dig decision), or possibly a deep non-ferrous (a dig decision). And as I noted, I was able to recover three more old coins that -- I am confident to say -- were "undetectable" with any other machine (as I explained).

Well, yesterday's park is an extremely trashy park, that dates back to the early 1900s. It is FILLED with both shallow, aluminum trash (pull tabs, rectangular tabs, etc.), and also a good many deeper, old aluminum screw caps (this park is within the flood plain of a nearby river, and has been flooded a number of times, and so there are areas with DEEP aluminum trash).

My settings were:

Threshold -- 0
Sensitivity -- 8 to 9
Disc mode
Volume 13
Black Sand OFF (most of the time)
6.4 kHz
Salinity Balance -- 50
Auto Ground Track OFF
Ground Balance (frequent rebalancing, when ground noise became apparent, with GB ranging from 600 to 700)


The hunt confirmed my early suspicions that the Tarsacci is not ideally suited for the type of detecting I prefer -- which is, cherry-picking deep, old coins. The VDI, in particular, is not accurate enough by any stretch, to allow for cherry-picking of targets. I was cross-comparing signals with my hunting partner, who was swinging his Equinox, and so this allowed me to find targets that I was unsure of, and then ask him how they were reading on the Equinox. There were a number that surprised me, and not in a good way. I can think of one that ended up being a beaver tail at about 6" deep; I was getting a good, clear signal on the Tarsacci, with plenty of VDI numbers in the mid to upper teens and occasionally 20 or so, but also bounces lower into the single digits at times. Tones were a mix between medium and high, but more high than medium; from the modulation, I knew it was not a shallow target. So, I called my partner over, and he showed 4 bar depth on the Equinox, ranging from 10 to 14 VDI. He said it was possibly a nickel. I was shocked, and sure enough -- beaver tail. I had a similar target later on, plenty of high tones and plenty of upper teens VDI, but this was a quieter tone, and so I knew it was deep. At between 8" and 9", I recovered a 1941 Jefferson nickel. NOT the target I was expecting (a mid conductor).

The bottom line is that aside from iron -- which either reads solidly as iron for the most part (low tones, and negative VDI), OR as a very solid, repeatable high tone but with VDI upper 20s to 30), nearly ALL targets exhibit some mixture of mid tone and high tone, in my dirt. While I'm learning to ignore the "wispy," staccato high tones (ground signal, and possibly iron flakes I presume), the fact that essentially all non-ferrous targets are varying mixtures of mid tone and high tone (and varying from single digit VDI into the teens and low 20s) make choosing what targets to dig very difficult, when trying to cherry-pick coins. As I've noted before, I like to be able to "call" a target, before I dig it, as being "right" or "wrong" is part of my personal learning process, that helps me to become comfortable with a machine. This is impossible to do, in my dirt, with the MDT 8000. The VDI and tones ARE accurate enough to cherry-pick shallow coins with some precision; I estimate 2" to 3" in my dirt, before a rapid breakdown to the mixture of mid and high tones/single digits and teens VDI that I noted above.

That is NOT to say that I have no use for the machine. It is clearly capable of finding deeper targets than any other machine I own. After a couple of hours of frustration, and heading back to the car, an interesting thing happened. I had hunted an area near my vehicle earlier in the day, where I knew there to be some deep old coins (it's an area I have hunted quite a few times before). The two guys I was hunting with and I spent some time in this area, while I was swinging my Equinox early in the hunt (one partner with his Equinox, and the other with his new Deus II). Each of us dug a couple of deep wheat cents, and my friend managing a mid-depth Mercury dime. So, fast forward to after I switched to the MDT 8000. On the way back to the car at the end of the hunt, I headed back through this area, knowing there would be at least a few deep coins available. Within a few feet of one of my plugs from earlier in the day, I hit a mixed mid tone/high tone target, that I could coax a fairly consistent high tone when sweeping from one angle/sector. It was mostly upper teens VDI from this sector (though the mixed tones/VDI would manifest, if I rotated the target). I dug it, and pulled a deep wheat cent -- from probably "Equinox max depth capability." However, for whatever reason, this target was not dug earlier. Within the next 5 minutes, and from within a 6-foot radius of the first one (and mere feet from a couple of additional plugs from earlier in the day), I found two nearly identical targets, with respect to behavior of the audio/VDI. Both were deep wheat cents. About 10 minutes later, and about 50 feet away, another similar target yielded another wheat cent.

So -- after hunting a couple of hours with nothing but frustration, I closed the hunt with four deep wheat cents within about 20 minutes time -- in and amongst other plugs from earlier in the day. This was surprising/a bit startling, especially after a couple of hours of nothing. Unfortunately, by this time, my buddies had left, and I lament that I was unable to "cross compare" with my partner's Equinox on any of these wheat cents, to see how they would have read on the EQX (or not read, as the case may be), to see if I could figure why they were missed by me earlier in the day when I was swinging my EQX.

I plan to head back to this same park soon, and experiment some more...as I am trying to see if I can "build upon" the nuances of the target behavior of those wheat cents. However, I am near certain that there are very few "clues" there, since as I said, nearly ALL non-ferrous targets beyond 3" deep, in my dirt, are a mixture to varying degrees of mid tone and high tone, and of single digits to high teens/low 20s VDI.

A few notes...

1. The audio frustrates me. There needs to be more audio adjustability. When I run the volume up, so as to focus on the deep, soft high tones, the shallow- to mid-depth mid tones are ear-piercing and painful. But, running the volume down to where the shallow mid tones are "comfortable," is too low to allow the already-subtle high tones to be distinct enough to catch my attention. I do not have this issue with any other machine. I also HATE having only 3 tones, after hunting for the last 10-plus years with Minelab FBS and Multi-IQ, always set at maximum number of tones. With that said, due to the inability for the MDT to accurately identify non-ferrous targets at depth, I don't expect that additional tones would be helpful.

2. Along with the MDT's obvious prowess on the beach, when in experienced hands, I think this machine would be an OUTSTANDING relic-hunting unit. I can foresee, for example, on a Civil-War hunt, where I would be digging most all non-ferrous, that this machine -- and its depth capability and its bad dirt capability -- would be the cat's meow. It's just not suited for cherry-picking deep coins in a junky park (though, in specific scenarios, it can do some impressive things).

3. I hate wired headphones (I'm spoiled now by the EQX).

I will post a few more thoughts as they come to me.

Thanks all!

Steve



Edited 4 time(s). Last edit at 03/06/2022 03:44AM by steveg.
Re: ON THE HORIZON = MDT-8000
March 06, 2022 12:17AM
OK, one more note.

I find the machine to be ergonomically uncomfortable. I am tall (6' 2" tall) and as such, with my long arms, I run the Equinox arm cuff in the rear-most cuff hole. This positioning allows the cuff to sit near my elbow, which thus allows me more "leverage" in terms of lifting the coil and keeping it floating (and of course, counterweighting also helps). On the MDT however, with 12" coil, it is quite nose-heavy, moreso even than the nose-heavy Equinox. And that nose-heaviness is accentuated by the "shortness" of the "bottom" portion of the upper shaft (the part that extends from the handle to the arm cuff). Given the "shortness" I am describing, the MDT arm cuff sits about "mid forearm," for me, as opposed to farther back near my elbow. When compared to the Equinox, there is about 3" less distance from handle to cuff on the MDT. The result is that leverage cannot be utilized as effectively, when working to keep the coil floating, and for me that results in the MDT being a notably more fatiguing machine to swing, particularly for my wrist.

I had pondered for a while on a way to design a counterweight for use with the Tarsacci, to at least partly remedy this. However, with the battery cap at the butt end of the shaft (which includes the rubber O-rings which are integral to the waterproofing of the unit), there's not a good way to permit a screw-on counterweight. So, that makes it more difficult to come up with a way to attach counterweighting. Further, lengthening that "bottom" portion of the upper shaft would also help the ergonomics, but given that the battery is integrated into that part of the shaft, and all of the associated things that entails, it's not a shaft that I can "redesign" as there are direct "warranty" implications there. So, there doesn't appear to be an easy solution to the ergonomic issues.

Steve



Edited 1 time(s). Last edit at 03/06/2022 03:48AM by steveg.
Re: ON THE HORIZON = MDT-8000
March 06, 2022 02:09AM
Really good report Steve! I'm glad you had another outing with the MDT.

#1 Yes. I too.....am certain that: the last 30% of the Tarsacci's depth capabilities......... is modulated too steeply. I run my Volume on '15'........ and have difficulty hearing the deeper targets.

#2 Concur with the armcup being too far forward.........and not back near your elbow.

I also have a terrible time pulling my thumb backward.......far enough to clear the screen....to invoke the pinpoint button. The control-head should be down the shaft...towards the coil....... by about an inch.

The inland/turf/dirt depth of the Tarsacci.... is phenomenal.,.,.,.,.,., especially in bad dirt. Yet, the ID is quite a bit 'splattered'; yet, if it's a non-ferrous target (at depth)....... the Tarsacci really tries to report it as a non-ferrous target. (Awesome for relic hunters.....in bad dirt; yet, a bit lacking for: exacting coin ID(s).

I too...... have dug fairly deep Nickels that ID'd as a high-tone.

Steve....... if you think of more data. . . . . . . please share/post!
Re: ON THE HORIZON = MDT-8000
March 06, 2022 04:18AM
NASA-Tom,

Thanks for your reply, and for actually reading all of my long-winded comments. It is very interesting that you, too, have dug deep nickels that ID as a high tone, despite your dirt being "mild." Interesting. I am glad to hear that you also concur about the "too short" length of the "arm cuff portion" of the upper S-shaft. I would LOVE to have a few more inches there...

As far as the audio, yes, you explained it better. Simply, the deeper targets are TOO modulated. Now, I LOVE modulation (soft tones for deep targets) That is key for me, in terms of quickly discerning depth (assuming coin-sized targets). But, with volume high -- to bring out those deep, soft high tones, a shallow mid conductor is just PIERCING to my ears. It's not JUST the volume, it's somehow in the mid tone pitch, also. Hard to describe. I WANT clear, obvious modulation, but there's no way that I know of to achieve that on the MDT without the shrillness of the shallow targets. Perhaps some sort of "add-on" sound equalizer of some sort? I used to just LOVE the modulation on the Explorers; I'd set mine at 7, and it was PERFECT. It was lost, to some degree, on the CTX. It seemed like the Explorer had pleasant tones, and a steady, almost linear drop off with depth. The CTX seems to be more weighted toward shallow and mid depth targets being nearly the same volume (very little modulation), and even the "moderately deep" targets having very little drop off in volume, but only VERY deepest targets then being notably quieter.

Interesting about the pinpoint button/screen location issue. I am not sure if I've noticed that; I'll pay more attention, but haven't noted it in particular.

Yes, I agree about the machine really trying to give a "non-ferrous" indication, even at depth, when it's a non-ferrous target. Perhaps I did not make that clear enough, but that is one thing I have definitely noticed. Iron seems to either fall in one of two "bins" of behavior...1). largely low tone/negative VDI (nails, etc.), OR, 2). very consistently high-tone, with essentially zero mid tones mixed in, and correspondingly very high VDI -- usually 27 or higher (wrap-around). These high-tone, high VDI iron targets are usually flat iron pieces. The only other targets that I have found to give such consistent high tones, are shallow coins -- a couple of inches max. So, what that means is, if modulation says the target is deep, and you are getting almost exclusively high tones AND your VDI numbers are all high 20s, this has ALWAYS been iron, for me. Meanwhile, non-ferrous targets, as I noted earlier, are a mix of mid and high tones. I've never dug a deep coin yet that didn't have at least SOME mid tones mixed in with the high tones which I did NOT expect to be the case (I expected more consistent high tones from coins), and no VDI yet that has been higher than low 20s. Now, to be fair, I have yet to dig a deep quarter or half dollar, so maybe those will be a more consistent high tone, and also more consistently low to mid 20s VDI, but...my long-winded point is to confirm what you said. Which is, IF the target is non-ferrous, it is pretty easy to learn to trust the clues that the MDT gives to let you know that (mixed mid and high tones, VDI below upper 20s). THAT is why I said it would be an excellent relic-hunting unit, in areas where there is iron, which you may wish NOT to dig, but where you would want to dig nearly all non-ferrous.

Steve
Re: ON THE HORIZON = MDT-8000
March 06, 2022 07:50AM
Hello to all,i also think the ergonomy of the machine could have been better especially with the 12" coil.

I ve mentionned before i had lots of fun on beaches,at depth,those almost unoticable sounds are fun to dig with soke good surprise sometimes.

RR
Re: ON THE HORIZON = MDT-8000
March 06, 2022 12:25PM
Steve......... one of the biggest/best learning-curves with the MDT...... is to go relic hunting a few times with it. THIS will train/teach/condition you to 'coin' hunt with the MDT.......... AFTER you relic hunt with the unit a few times!!!

Rivers Rat......... yes. The 12" coil is not so 'ergonomic' on the MDT. BUT....... I have to say this: It was developed 2-1/2 years AFTER the inception of the MDT! Soooooo....... the ergonomics are designed to the original 11" x 8" coil.
Re: ON THE HORIZON = MDT-8000
March 07, 2022 02:33AM
Steve........ a couple more things:

You are in the steepest part of the learning-curve........ which is the most difficult portion......... where many have quit.

ONE of the primary things (part of the O.S.) about the Tarsacci is that it looks at the 'density' of a target. The harder the object ..... the higher the Tarsacci's ID. Conductivity is also one of the ID tools the Tarsacci analyzes; yet, via a different O.S.
We have become accustomed to Phase-Shift of an object ........ with traditional detectors ...... for generating ID. The MDT is quite different. If the MDT was a 5 or 6 Tone unit....... ID's would be more 'jumpy'....... due to the different analysis O.S. platform. ID's are not as accurate as a (common) modern VLF/SMF type of unit; yet, the Tarsacci will punch deeper in bad dirt....... and generate a ferrous/non-ferrous ID more correctly than conventional VLF/SMF units.
JCR
Re: ON THE HORIZON = MDT-8000
March 07, 2022 04:16AM
Steve, Are you still using the wired Tarsacci supplied headphones? If so I think you will find the modulated volume you want & need to HEAR the softer deep targets AND not get blasted by shallower targets with a pair of high ohm headphones like Killer B's/Sun Ray Golds. They also have a limiter if needed. That was the best, most helpful change for me. Night & day difference.

Chris
Re: ON THE HORIZON = MDT-8000
March 07, 2022 05:05AM
NASA-Tom -- interesting, and I think I can imagine why this would be the case. Unfortunately, my opportunities to do so (military-type relic hunts) are limited in Oklahoma. What I need is another opportunity "back east" to on some property that had Civil War activity...

Steve
Re: ON THE HORIZON = MDT-8000
March 07, 2022 05:16AM
NASA-Tom Wrote:
-------------------------------------------------------
> Steve........ a couple more things:
>
> You are in the steepest part of the learning-curve
> ........ which is the most difficult portion......
> ... where many have quit.
>
> ONE of the primary things (part of the O.S.) about
> the Tarsacci is that it looks at the 'density' of
> a target. The harder the object ..... the higher t
> he Tarsacci's ID. Conductivity is also one of the
> ID tools the Tarsacci analyzes; yet, via a differe
> nt O.S.
> We have become accustomed to Phase-Shift of an obj
> ect ........ with traditional detectors ...... for
> generating ID. The MDT is quite different. If the
> MDT was a 5 or 6 Tone unit....... ID's would be mo
> re 'jumpy'....... due to the different analysis O.
> S. platform. ID's are not as accurate as a (common
> ) modern VLF/SMF type of unit; yet, the Tarsacci w
> ill punch deeper in bad dirt....... and generate a
> ferrous/non-ferrous ID more correctly than convent
> ional VLF/SMF units.

NASA-Tom -- this is most interesting. Density. Something I've been pining for detectors to be able to give a hint on, for a long time. Is there any discernible intelligence, with experience, in differentiating say a man's 14K gold wedding band (ID 18-19 on the Equinox) vs. one specific (very old) type of rectangular tab that I dig that also IDs 18-19 on the Equinox?

Also, regarding the "learning curve," do you have any clues you could give, as I seek deep coins, as to what "subtleties" I might be looking/listening for? Something to help flatten the curve a bit? Unfortunately, most nearby spots are so sparse, with respect to deep/old coins at this point, that there aren't enough of them for me to "practice on." Not enough "reps in the batting cage," so to speak, which makes it tough to train yourself on a new machine...

Thanks!

Steve
Re: ON THE HORIZON = MDT-8000
March 07, 2022 05:22AM
JCR Wrote:
-------------------------------------------------------
> Steve, Are you still using the wired Tarsacci s
> upplied headphones? If so I think you will find th
> e modulated volume you want & need to HEAR the sof
> ter deep targets AND not get blasted by shallower
> targets with a pair of high ohm headphones like Ki
> ller B's/Sun Ray Golds. They also have a limiter i
> f needed. That was the best, most helpful change f
> or me. Night & day difference.


JCR -- yes, I am in fact using the Tarsacci phones.

I DO have a pair of Sun Ray Pro Golds -- I LOVE those headphones, on the Explorers/CTX. BUT, all I have is the CTX version, and -- if I recall correctly but COULD be wrong -- I tried them on the MDT (with a 1/4 to 1/8 converter), and they didn't work. Again, I COULD be wrong, but I'm pretty sure I tried them.

I am happy to buy another set (Pro Golds or Killer Bees) specifically for use with the MDT, if the CTX version indeed won't work, but I would want to be sure I bought the right pair. Can you point me in the right direction? This sounds like it could REALLY be what I need, based on what you are saying. And I didn't even know that these phones had a "limiter," nor have I ever used that function on a headphone, but I can imagine exactly what it's for (puts a "limit" as to how high volume can go, allowing you to crank up volume for softer sounds). I need to get some of these ASAP...that will work with the MDT...could be EXACTLY what I am looking for!

Steve
Re: ON THE HORIZON = MDT-8000
March 07, 2022 11:49AM
Ergonomics aside, I put the 11x8 inch coil back on the MDT yesterday to hunt an old permission that RodPa took me to. He warned me the property was machine gun iron, all over . . it was an in-town property and the town was built next to a good size creek. A place where there is no spot to GB. What I want to say is this coil has a better feel to it, not only weight wise but function and a better feel for the ground and it's contents.

I didn't notice it before because I've had the 12" on since I got the coil. Switching back and on this hunt is when I noticed it. I ended the day with a 1906 IH, a silver piece of unknown style jewelry, 3 wheat's, small bronze flat piece with designs and of course normal junk. We were only there about two hours.

Thinking back, the two beach trips I hunted this past summer and the one before. . . the smaller coil out performed the 12" in a big way. I believe I wrote about my first beach trip with the MDT and the smaller coil . . it was unbelievable the jewelry I dug in a few short-hour days.
This coil is going back to work while the 12" takes a long break.

NASA Tom, were the 11x8" coils matched/paired to each particular unit? If so, that could be the reason for the performance difference I felt.
That smaller coil separates very well. Picture in one swing an iron tone about every 3 inches, machine gun. . . .in between, a high or mid tone peep . . .back over the target to try to single it out or determine if it was a wrap of iron. It was easy to isolate the high/mid tone between iron. When digging out the non-ferrous target there were iron pieces in the hole, happy boy.

I'm not dissing the 12" but the 11"x8" is kin to the unit, at least it feel that way.
Re: ON THE HORIZON = MDT-8000
March 07, 2022 02:15PM
I like the coverage of the 12" .... but length wise there seem to be the same size. I switched back to the standard this winter there seems to be a good difference in settings in the water enough to make me go hum. Salt setting can be run very smooth 4 digits less...... if what Aaron says is true then that could make a difference in small gold. I dont dirt hunt anymore so i dont try to throw my 2 cents in there even thou ive a pretty good idea once learned and finding the right swing id be able to pick thru trash with the standard trash. Worked with the Explorers. Like in most case i believe if you hunt with a machine long enough you can get the most out of it. I agree there could be some adjustments made to the cuff and the handle, but nose wise bigger coils throw that off and have on most machines. I dont really notice the weight.... but i did when i switched to the Nox one day .... it felt much heavier to me. You have to remember Dimitar i believe build the machine around the coil rather than the machine first.

Ive always liked the Pro Gold phones.... but i believe most of the better dirt phones use AudioSear speakers so its about sealing the speaker and muffs that make a difference.
Re: ON THE HORIZON = MDT-8000
March 07, 2022 03:27PM
Steve & Steve,

Nutshell:

Yesterday...... I hunted a site with Tarsacci equipped with 12" coil. It's about a 1/3-Acre lot in the middle of the old town of Titusville, whereby.....a 1891 home was 'lifted' (and discarded) ..... somewhere around 1939. VOLUMES of nails. The type of site that does NOT allow you to rotate your body around a target (when you find a good signal).... to better analyze the target.,.,.,.,.,.,.,., due to the fact that you would rotate your body and coil into more nails. You simply had to deal with whatever 2-way signal you received......and make the best of it whilst your feet were planted still. ----- Some takeaways:

* Dug a clad dime that ID'd as '29'....... but audio sounded reasonably good.
* Dug a silver dime that ID'd as '30'..... but audio sounded reasonably good.
* Dug a copper penny, (a 1960).....about 3" deep...... that ID'd as '30'.
Additional data-points = I...... VERY MUCH ...... wanted to throw the Tarsacci in the trashcan. It was VERY frustrating these coins ID'd in the "iron wrap-around" ID range. NOT funny. NOT fun. Large sheet-iron ID's in this (29-30) range.
But.............. a 'saving-grace'. On one (and only one) of these coins ...... did I 'feel' the ""need"" and confidence to want to double-check the target....with another unit. For historical, nostalgic, site-specific reasons....... I wanted (NEEDED) to check it with a CZ-3D. The CZ-3D constantly/continuously/consistently/reliably ID'd the coin as 'iron'. There was one (and only one) high-tone hit on the coin with the CZ-3D....... out of about 70-80 sweeps.....,,,,,,,,........and I clearly knew it was that elongated, terrible preamble, terrible audio body.....and terrible (washed-out/smeared) post-amble high-tone response of "falsing iron". Bottom line: The CZ reliably called the coin as "iron". This particular coin happened to turn out to be the silver dime......fortunately. (Nearly Uncirculated Mercury, 1917). Because the coin was UNDER the porch (almost under the house)....... the coin had a very slow/decelerated sink-rate...... (((under the porch is out-of-the-weather/mother nature; hence, near-zero sink-rate)))........ so it was only at a depth of 4". {{{Remember....... the house was removed........no longer exists}}}.
I really wished that I had checked the other two coins with the CZ-3D....... but there was not enough confidence in the signal to 'prompt' me to WANT to (or even think of) double-checking with another unit. Only the silver dime 'triggered' me.
Strange that the Tarsacci would ID this shallow (only 4" deep) silver dime as '30' !!!!!!!!!........ UNTIL......... you REALIZE that NO other unit would have even found the 4" deep silver dime! All other units would ID this scenario/situation as 'iron'......due to all of the rust flakes/flecks and little bits/chunks of iron.
While I cuss & curse-out the Tarsacci....... the epiphany sinks in. It may 'struggle' with that silver dime (and plenty of strugglings with other coins)....... but at least it did NOT ID the coin(s) as a 'iron tone'. . . . . like all other VLF (and SMF......or otherwise) units.

More things to be said about this particular site.......and the experiences of/with the Tarsacci:
I was on 6-KHz. All the tons of scattered chewing-gum foil...... REALLY kept the headphones "busy" on the EQX. But with the Tarsacci on 6-KHz...... most of the chewing-gum foil was not even detected/heard....... due to 6-KHz desensitizing on small chewing gum foil. And...... In this case: that's a BIG "plus".
The Tarsacci (whilst on 6-KHz) would only give a low-tone audio report....... if a actual/solid nail was passed over. With the EQX (and CZ)....... the head-phones were 'lit-up' with a continuous barrage of iron-audio. Especially with the EQX...... it is very sensitive to even the smallest iron flecks/flakes of rust. The Tarsacci cannot see them (on 6-KHz). The rust flecks/flakes are 'timed-out' with/by the Operating System of the Tarsacci. . . . . . . hence/so...the audio is much more quiet on/with the Tarsacci.
What's neat is............ I have learned to ignore the ID numbers on the VDI of the Tarsacci. I am BACK TO full focus on the audio: nuances, quality, sharpness, preamble, amble, post-amble...... breadth-width-girth of the audio. Example: sheet-iron (sheet-tin/sheet-steel) is a larger.... more 'broad' high-tone audio response; yet......... a coin is a very short breadth-width-girth audio response.,.,.,.,.,.,.,. and the preamble & post-amble of the audio is very sharp, clear, crisp, concise (square-wave).

Many times...... I still want to throw the Tarsacci in-the-drink. I still struggle (too much) with digging deep nails........and especially square-nails. So far..... what I have learned.....(and it's a big attribute/trick) is....... in an area that allows you to rotate your body around the target (not like sites that are carpets of nails)...... you will dig a high-tone that you can rotate your body around the target....whereby..... 30% body rotation presents a high-tone audio........on nearly any/all VLF/SMF units. This is NOT true with the Tarsacci. You need to ascertain a high-tone at minimum.... 70% of body rotation around the target!

SteveO......... I have not yet tried the standard/stock 11" x 8" coil at this particular site. (It may behoove me to do such). (((It'll change % body-rotation numbers requirements!))).



Edited 1 time(s). Last edit at 03/07/2022 03:30PM by NASA-Tom.
JCR
Re: ON THE HORIZON = MDT-8000
March 07, 2022 04:37PM
That is an interesting thought; that the coils might be tuned to each unit to some degree.

Chris
JCR
Re: ON THE HORIZON = MDT-8000
March 07, 2022 04:53PM
NASA Tom, What headphones are you using with the Tarsacci?

Chris
Re: ON THE HORIZON = MDT-8000
March 07, 2022 05:34PM
NASA Tom, during yesterday's outing, I did not at all have the urge to wrap the MDT around something. It was a day of loving it, lol. Usually an ID of 29 or 30 with whisper high tones all around means a deep old crusty nail or rusted iron bolt or nut . . in soil around here anyway. I usually run 6KHz, yesterday I was on 9KHz. At the front & side of the house there was some EMI, weird, the back, nothing. All the power lines to the house were overhead. Rod mentioned that he was killed with EMI on previous hunts, so my back up was the CZ. Rod is running the EQ 800 . . .he does well with that unit.

That place is on the market so Rod should hit it as much as he can before it sells . . .there's more to be found over there in all that iron.

PS; In high iron, I have to pinpoint to get the closest location of the target before I rotate. Many times it PP's a couple targets, so I pick one. I also will only rotate 90 or 180 degrees verses 360 before I make the decision to dig. I will also cross the target with the coil and stand in one spot. A lot of these little rituals depend on the sound and circumstances.. . fun stuff . . it was good to get out.
Re: ON THE HORIZON = MDT-8000
March 07, 2022 09:34PM
Gosh. I'm failing at a couple (memory loss!) things:

The Tarsacci is indeed BUILT AROUND THE COIL!!!!!..........BUT.........you CAN interchange 11" x 8" coils with other units. NOT a problem! It's just that........ the coil was built/invented first.

I use 1/8" stereo-jack equipped headphone KOSS QZ99's for EVERYTHING!!!!!!........ to include on the Tarsacci.

SteveO....... good methodology for pre-dig target identification. ----- And yes. There are sites that the Tarsacci will incur no EMI........and the EQX will be terrible. Then.......at a different site....... the Tarsacci falls flat-on-its-face due to EMI...... and the EQX is just fine.
Re: ON THE HORIZON = MDT-8000
March 08, 2022 07:39AM
NASA-Tom,

Wow. What a ton of information there, and I will read it through again to digest it all.

A couple things...

It's great to hear that you, too, struggle at times, with the MDT. That is helpful to know. It's also interesting (frustrating) that one "tell" that I had thought I was catching on to, about high VDI numbers being "flat iron" is NOT always going to be the case. But, it's also interesting that you are noting that there is subtle "intelligence" in the tones themselves. I will have to listen particularly closely, and try to learn some of that. I'm not there, yet. The audio is still "odd-enough" to me, that I haven't moved to the place where I can try and discern subtle clues like the ones you mention in the pre-amble, body, and post-amble.

It sounds like your hunt was much like mine, in some ways. In other words, if you just look at the end result, it doesn't look bad at all. You came out of there with a silver dime, which -- in all that iron -- had to be satisfying. BUT -- those "prizes" don't seem to come without much frustration and effort, with the MDT, LOL! What I mean is, I dug more wheat cents in 20 minutes yesterday with the Tarsacci, than I did in two hours with the Equinox, in the same area. BUT -- aside from that 20 minutes digging those wheat cents, the other two hours with the Tarsacci had me ready to "toss it in the drink" as you said. It's really puzzling to me that I dug three wheat cents with the Equinox, but had a very pleasant hunt, knew what targets to dig and not dig, understood what the machine was telling me that was in the ground under my coil, and as such, dug hardly any trash. Then, I dug four wheats in the same place with the Tarsacci, but struggling mightily with what the machine was telling me was in the ground under the coil, digging targets that SHOULD NOT have ID'd where they did, and feeling just lost, for the most part, when trying to make dig vs. no-dig decisions.

It's strange...

Steve
Re: ON THE HORIZON = MDT-8000
March 08, 2022 10:49AM
JCR Wrote:
-------------------------------------------------------
> That is an interesting thought; that the coils mig
> ht be tuned to each unit to some degree.

I have 2 Tarsacci units and the 11” x 8” coil works great on both units. I prefer it for working the beach, and in iron infected sites. It seems to have a faster, more accurate pinpointing and provides me with a quieter operation (Less audio fatigue as Tom calls it). While the 12” (on either detector) picks up more ground minerals, tends to require less sensitivity to run stable and I find I can’t pinpoint with it as well as the original coil, it covers more ground and it is a bit deeper depending on conditions, so it has it’s places where it’s just a good choice for the hunt.
Re: ON THE HORIZON = MDT-8000
March 08, 2022 01:31PM
I wish i had a space for a 2nd MDT....


I may need to refit the 9x11then



RR
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