ON THE HORIZON = MDT-8000

Some one asked me the other day if the MDT would pick up small targets. Well i was doing a dump of my finds pouch this morning after a couple hunts. Ive only found a couple of tiny pieces of gold i tests the MDT didnt like as well as the Nox. Tiny cross and very small piece of gold chain........ BUT, the Xcal and CTX werent any better. I feel pretty comfortable im not missing much in the wet sand........ and in the water it may have an advantage over anything else ive used. I know its sure quieter than the Nox out there.

Yup, that pile o trash looks familiar....

A few things:

On MY beach...…. my Ground Balance numbers are:

18Khz = 26
12Khz = 27
9Khz = 29
6.4Khz = 37

The good thing is...….. Once you perform a Ground Balance in each Frequency...…. the unit will remember each Ground Balance setting for each specific Frequency.,.,.,.,.,.,., even if you pull the battery out of the Tarsacci. Throughout the year..... I have only seen/witnessed no-more-than a 1-digit 'change' in these Grnd Bal numbers; usually dictated by water temperature (which dictates how much 'salt' can be held-in-solution).
Also...….. If I forcibly change the Ground Balance numbers to: 2-digits "off" of balanced/tuned...…. the unit becomes a bit 'chatty'. . . . . . in MY wet-salt beach conditions.

For my last 7 beach hunts...…… Black Sand = "OFF"...…… has yielded greater than 1" additional depth on rings & coins. Many months ago...…. whilst testing the Tarsacci….. Black Sand = "ON" yielded a slight performance increase...… with a slight stability increase. Lately...….. the tables have turned. . . . . . and by a fair amount.

Interesting info Tom on the Salt Balance and good to know that it aligns with what I am experiencing over here with only slight variances in numbers. Not sure why I "assumed" it would be opposite with the lower frequencies needing a lower SB number.

Also interesting in the change in depth you have experienced with BS on/off over time on your beach.

Cliff

Tom...... does the BS issue have anything to do with you being sanded in.......or buried sea weed? We get sea weed on this side of the island that get buried ...... it tends to collect BS... and can really make a machine chatter as sand is removed. Or could it be all that fresh sand has NO minerals at all? You also have larger sand than we do.... bit more air gap. Interesting that you mentioned temp could change the salt setting. Cliff i can see where you might think that....... sensitivity of the higher freqs picking up more ...... but i think thats why its lower. So its odd i guess that i could get the higher freqs to settle down in deeper water with extreme salt settings.

Sea weed does look like a target to a sensitive detector. Right now...… I do not have sea weed scattered on the wet slope.

Yes; Black Sand ON/OFF (variable) performance most probably has to do with what 'type' of sand is currently exposed. Right now...… there is a very light tan silica/quartz sand that is exposed. I'm waiting (wanting) a NorEaster to remove a fairly large amount of sand...….. so as to 'expose' the dark gray high-density sand; so I can see what this does to Black Sand Mode, Salt Balance...… and Ground Balance. When this dark gray (almost black) sand is exposed...….. I have concerns about proper Ground Balance. . . . . . . because. . . . . . I will (then) no longer be able to perform a Ground Balance on the dry sand...….. then walk down to the wet-salt slope to perform a Salt Balance. This is to say: A Ground Balance would be performed in the tan/yellow dry sand...…. then walk down to the (erosion area) dark gray wet-salt slope sand...…… which is of completely different mineralization structure...…. as compared to the dry sand. When the WET slope exposes this dark gray sand...…… the DRY sand still remains a light tan/yellow structure. Apples-to-oranges.

Tom, my situation is very similar in that our wet sand often has a very different mineral structure than the dry sand.

Unless someone can come up with a magic ground balance formula, it sounds like it's going to take a lot of depth testing to find out what GB setting works best on a particular beach. We have some warm weather coming this week so I'll be doing just that.

.

cdv Wrote:
-------------------------------------------------------
> Ok, let me ask a general question about the salt b
> alance.....I spent most of my 30 odd hours with th
> e machine in 9 KHz running with a salt balance of
> 27 - 32ish depending on beach and whether wet or
> water hunting, today I decided to try 18KHz and fo
> und it noisy with my normal settings (30 at the ti
> me) on the wet sand. I finally decided to adjust t
> he salt balance (expecting to raise the number) bu
> t found raising it made it worse.....ended up find
> ing a SB of 25 was quiet and stable.
>
> Do you find a lower SB number with the higher freq
> uencies?

I have had the exact same results. 6.4, 9 & 12 salt balance is the same 27. But to quite down 18 I have to reduce the salt to 25 in wet sand and wash. It puzzles me.
>
> Cliff

There won’t be a do all GB I don’t think.....it more finding that 0 ground balance so to speak. Just like on the Nox you will get chatter near hard pan and it will get quite in the fluff. Tracking might keep it consistent but at a depth loss. Ive always asked that question about GBing at least in the damp sand...salt balance has been determined and saved in most cases from previous hunts so shouldn’t it be only seeing the minerals at that point not the salt? Mine don’t like to GB either....but it reacts like the Nox...I get higher GB than I do the closer I get to the water. Looking forward what you find Tom.

Had Tony Eisenhower do me a pair of phones for the MDT. I wanted a pair that if i want to stick my head under water i can with confidence. Ive already hooked um up for tomorrows hunt. Notice he used an angle M8..... these are solderless and he angled it over the shaft so it kind stays out of my way. These things have a great sound to them..... and are loud.

Just can't seem to get over the gold. Conditions are as flat as it gets with just a small shell area with a harder base. Sand has got to be 2' deep near the water. Still was able to get some targets worth notice. The center piece in the costume jewelry is a tooth crown. Also the ring is silver and its been in long enough to tarnish. Has a name and some design on the front. Some of the tabs were laying on the hard bottom under the shells and the 920 scoop and several inches of the pole were below ground level.

Feel your pain....... same conditions here sand sand and more sand. Sometimes it doesnt matter how deep your new machine is ....... especially if the sand has moved in.

Well i spent the morning with Tonys headphones. I like the 9 0 clock angle on the M8 puts the cable over the top of the upper shaft. With this S shaft i tend to run my index finger down the upper shaft ....... much like you might with a pistol for safety. Gives me a lot more coil control..... but i was kind of hitting the 6 0 clock one that came with the machine. Now a little info on what ive found about water phones........ a pair with piezos and a pair with speaker (audiosears). Both are loud....... the difference is in disc. The speakers tend to have more volume and are very crisp tone (like Pro Golds)... more responsive to minerals.... which can mean they can make a machine like the Nox more chatty. The advantage to using piezos on this machine seems to be a couple of things. First ...... not as much chatter. They might not have the volume in disc. Up side seems to be with iron. Speakers since they are more responsive tend to give some wrap around high tones off iron in AM. Piezos seem to be easier to NULL the iron when switched to disc. That can speed up the process to determine if the targets worth digging out there when you cant see the screen.

SN, what is the crown made of?

I found a crown two weeks ago. It was grey when I dug it and I didn't think much of it, but later when I got home, I started buffing it. It turned out to be 18k gold. A few days later, a friend of mine found the entire dental bridge that it went to with four more crowns in it..

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Edited 1 time(s). Last edit at 03/08/2019 08:08PM by Badger in NH.

Haven't had the opportunity to look but thanks for the tip. First one I have found so kind of rare and would have kept it for laughs. Have a guy in this area that has a contact at a crematory and he goes after they have had the ceremony and hunts. Has had a great deal of luck.

Finally got over a ring in the water. Soft sounding and took quite a while to finally get it....how I wish I could say how deep it was but it definitely was down there..Satisfying for a short hunt.

Running 6.4 KHz, All metal and switched over to Disc and heard a lower tone, water was murky so I couldn't see the screen for an ID number.

Cliff

That was a nice ring Cliff. What made you choose 6.5khz?

Heres mine for the day....... 1.5 grams 14K band, SS, and a @#$%& rose gold plated copper/silver metal. The gold one surprised me most it was a little deeper than i expected ..... 5" range in the ankle deep water. Not much out there deeper...... HIGH tide pushed by wind..... and cool so not many deeper than waist deep..... even those had blue lips lol.

Dew, to be honest, I just decided to start at 6.4KHz and see how that worked....only 30 minutes in I got the ring and figured why change.....

Cliff

Wonder why PAn-Dora isn’t allow on here? Cliff I know back in the day single freq machines ran 5 to 7 kHz.... fairly good depth, not affected to much by EMI and it liked high conductors a tad better. I noticed on iron with the way we have our disc at 28... it seems to knock out the wrap around pretty good. Have you noticed your targets starting out high...let’s say 18 on a pull tab deep .... then as you get close the digit may return to around 6? On unknown iron signals.... it tends to throw high digits more if it’s iron.... on nonferrous you may see a jumpy iron signal...but it throws an occasional low digit which is within a digit or two of what the target is.

Cliff & Dew...…….. congrat's to both of you...… on your gold ring finds...…. especially in the winter!

On a different note; I needed to perform a standardized test with the Tarsacci……. to verify: no bias. All-to-often..... It is so easy to 'overdrive' a new unit to some form of extreme performance...… so as to 'force' the unit to "pass" a certain test whereby..... you already know the exact pinpoint location of a deliberately buried target. Said differently: It is so easy to set up any detector to a level of performance that you could never hunt with...… due to overdrive instability; yet, it'll "pass" a test in a 'controlled environment'. My standardized test-targets were Nickels. I had a friend bury (on the wet-salt slope) 7 Nickels …… each Nickel at different sections of the slope...….. so as to test the performance of the unit when exposed to varying levels of underground water-table salinity levels. Each Nickel was buried at exactly 14.0". . . . . . and I was not allowed to know their location. This would force me to run the detector at a 'huntable performance level'. . . . . and not some overdriven fictitious unusable performance level.
When I commenced hunting...… I tried two other top-end units first. Zero of the 7 Nickels were found. (((Mildly surprising to me..... specifically from an engineering standpoint))). I then switched to the Tarsacci…… and ran the unit at a very huntable/usable level. 12Khz would be used for all of the testing. I used Sens '8' and Thresh '-1'. I could have easily used a higher Sens setting.... and/or a Thresh of '0'; yet, wanted to know if the unit could be configured that a average seasoned detectorist could: 'hunt'...……..and...……...'find' these Nickels. I was able to find 6 of the 7 Nickels on the first try. On a second attempt...….. I found the seventh Nickel. (When I stood up from one of the targets.... I created/had bad overlap..... and initially missed the seventh Nickel). Also...…. after all 7 Nickels had been located...… I switched to 18Khz....and could easily hear each individual Nickel; yet, I must disqualify this test...….as...….. at this point...…. I already knew the exact location of each of the 7 Nickels. I speculate that I could have found all of the Nickels in 18Khz.
The interesting part about this test (to me) was...… I had also detected/found 4 iron items in the process of trying to find the 7 Nickels on the beach. I was able to correctly ID the iron items (3 bobby-pins and one fish hook)...….. and continue to find the remainder Nickels. And one of the ferrous/iron targets was at threshold depth.
Yes...… I too …. would like to see what the Tarsacci would do (depth-wise)….. if it had a larger coil; say: a 11" round DD coil.

Tom..... when i run my testing over known targets my machines are normally set up the way i normally run them. Yes i do some adjustments on a known target..... but then i have to consider can i run those settings..... and when. Thats the tell for me as to which machine i might use in a given situation/condition. You mentioned it early on...... coil control is VERY important as is location on the coil or recognizing near targets. We also tend to get into a mental daze out there....... trying to cover more sand. Staying focused, slowing down, and not worrying about what the OTHER guys are doing can change your results. Testing can be an eye opener....... but its still ..... you dont know what missed if you missed it so testing is important. Machine choice can come down to knowing what you have to sacrifice ..... vs benefit.

Tom, interesting test AND results.

I have a few questions.....my assumption is you were in All Metal mode for the hunt, how was the ID on those nickels at 14"? Bouncy +/- numbers or mostly +?
Did you switch over to a different mode(s) to make an ID decision?


Cliff

Dew & Cliff...…. Your testing (and head-to-head testing) has been performed with mild or medium settings. I am in no way inferring that you had performed any of your testing.... with 'overdrive' (unusable) settings!!! I'm just simply stating one of my personal pet-peeve's...…. in which I see some folks make this easy-to-make.... mistake.

Cliff...….. actually...….. for this specific test...…….. I was in "ID" mode. (((Not the: All-Metal Mode..... and not the: Mixed Mode))). This is a very important point...… that I should have posted!
These 14" deep Nickels …. very reliably ID'd as non-ferrous..... but unreliably ID'd as NICKEL. I could easily guess that the conductivity of the targets were in that 'Nickel' ID range; yet, they could have easily been a solid/hard piece of can-slaw.... or chewed up soda-tab. On 4 (of the 7) Nickels...… I did indeed switch over to the All Metal Mode.,.,.,.,.,.,.,.,. only to see that nothing changed. No added/subtracted intel ascertained. But...…. the All Metal Mode does run smoother..... and does allow for USABLE higher gain settings. This is 'where' and 'how' you can use the All Metal Mode..... to take additional advantage of its expressed smoothness...…… via allowing more audible intelligibility of the small "telling" variances/aberrations of the sand/conditions.

Have you noticed upping of targets? Like a pull tab....reading 12ish then going back nearer 6 after the first dig? Great info Tom. True our testing is done with our hunting settings which are milder but could be a bit higher. We are still finding our grove out there.

If the tip or heel of the coil is passing over a target...… I do see/experience up-averaging. If a target is quite deep; yes, I also see some up-averaging.

We got no testing done today....3 of us worked a beach for 6 or 7 hours. I think we all came away with a ring jus not gold. Nothing there it seemed but iron. By time we ended I think we were all dragging ...waves had picked up and it was one long walk back to the car for all the test stuff. Always enjoy a day of hunting with Cliff I get a lot of good info from him. Some days it just don’t matter what ya swing this time of the year. Targets we did find seemed deep. We did notice the machine don’t like each othe if running the same freq. also think you don’t put torque on a cuff in the water? I already broke my Nox on and today completely turned my MDT one sideways.

No wonder my arm was starting to chafe up near my elbow...… I just went out to look at mine Dew, yup, it is off to the side. Minor adjustment, at least it didn't break like the Nox did....

In addition to what Dew said about the machines not liking each other.... IF we were hunting with the same frequency AND got within 10 feet of each other, your machine would get chatty. Funny thing is, we both wanted the same frequency so we just stayed over 10 feet away and all was good.

Fun hunt even though we didn't strike the gold today.

Cliff

Dew..... if needed (and it sounds like you do)…… you can put a little greater 'snug' on the 4 stainless screws...that holds the armcup on to the carbon shaft.

Only 10-feet from each other...…. and on the same Freq? Hmmmmm. Not bad; yet, I would try to stay about 30-feet apart from each other....,,,,,,, just in case there is silent masking.

Tom..... way ahead of you...... done that as soon as i got home. Cliffs last comment as he was leaving the beach was wow i really like how quiet this machines runs in the water. Depends on the machine, but it dont like some Xcals either. 30' ...... well thats not likely going to happen since we both like to talk. Ill just convince Cliff to run another machine he can noise cancel lol. Besides if he started digging to many targets it was easy to get within 10 ft then hunt behind him. I figured he has a big enough advantage by being a foot taller than me. I kept showing him some of the very small to tiny targets i was getting IN the water.......some i just stopped chasing. I felt like i was getting pretty good depth on those. Cliff also made the comment after straddling a hole he was digging ....... im not sure i want a machine that goes deeper than this .... especially if i cant ID the target. I didnt seem to have an issue IDing Iron..... even deep iron seems to have a tell. But..... we both would really like the MODE button and PP button swapped.

As for swapping positions of the mode and PP switches Dew, I think IF the size of the mode switch was larger, it would be easier to push without looking. Not using a glove on my detector hand helped but even then, I managed to turn the machine off once when TRYING to switch to Disc. I actually rarely use the PP switch and do find its location not ergonomically located for my right hand. PP functions well when I do use the PP function.

Cliff

I own a Equinox 800. First hand, I got to witness the Tarsacci go a few inches deeper than my Equinox on a nickel, at the beach. If the world catches on to this, Minelab might need to do something about this.

Aaron