Ok been using the MXT for about a week now

[burried gold]

I have done about 3 hunts with it. I like the 4x6 coil it works good and gets good depth for a small coil. but I put the 9.5 coil on and went out to the park ground balanced and checked ground balance and buried a silver dime at 6" I then in the relic setting swung over it and even with the dial turned all the way up I got a broken signal that was partially in the mixed mode all metal sound the VID was ok bounced around alot but mainly stayed in the coin range. ground reading in prospect mode was at around 75. my guess is that 6 1/2" would have been a whisper and 7" would have been out of range. is this normal for depth that everyone else is getting on their MXT? My DFX was quite a bit better on depth buy a couple of inches in mixed mode and had solid hits at around 8" on dimes in the same area. should I be getting more depth with everything considered

 

[usafaviator]

Try it in C/J mode and see if you get better results. My MXT goes deeper than 6" with solid hits and VDI. YMMV though.

 

[JohninNC]

USAFAVIATOR is right. I have found C/J to give better depth. Also the 10" DD will give a lot more depth.
John

 

[Nancy-IL]

Using your stock coil should get you a lot more depth. It's very unusual to not hear a strong hard target at 6". I've found tiny 1/4" snaps at that depth with my MXT. Keep detecting and the more you use your MXT, the more you're going to love it. Practice practice practice. You're on the right page! HH, Nancy

 

[ToadWhisperer]

Did you check to make sure you where in a clean spot and nothing else was buried next to the dime?

 

[HuntinDog]

Masking from other targets if the ground was not clean can cause that.
Also a fresh bury won't have a "halo" and if you put it in the ground on it's side it would be even smaller. Hence the weak signal.

HH

 

[Monte]

having owned 6 MXT's and 5 M6's I have never had a problems getting a hit on a dime or penny-sized coin at 6" or less .. unless .. it is just a fresh buried coin in unfriendly ground, or there are nearby masking targets. And to top that, most of the time I'm using White's 6

 

[burried gold]

yes it was freshly buried. and i was not super worried about the low depth. i forgot about the halo thing. i knew it could do better because i have dug a couple of ring tabs at the 7" to 8" range. i have not done much with the c&j mode yet mainly because i have had a hard time adjusting to the single tone so i have been using the relic alt mode to get the two tones. i will try c&j to see if it is the same thanks everyone

 

[Monte]

i forgot about the halo thing.

This is from a 'Tips' presention/write-up I've done regarding a 'halo effect.'

I will try to be brief, which I know is a tough one for most readers to imagine, but let me just state that, from the standpoint of metal detection electromagnetic field disruption, there isn't going to be any significant 'halo effect' from most coins. This is especially true if the coin is made of gold or silver or some other noble metal.

Yes, I will agree that over time, and I mean ample time, there can be a very minuscule leaching of surface metal that is on and about a buried metal target, but not always. For example, gold will not degrade at all. Silver will, but very, very little. Long ago, when I was first starting out in this great hobby, I read a lot about the illusion of a halo effect. It was stated then that if the coin was a silver type, and if it was firmly positioned and had an ample amount of ground chemical interaction and moisture present, it would take about 1 year for it to reach its maximum amount of 'decay,' to use that term.

Copper coins were or can been observed with more apparent degradement, but only if there is ample bad soil minerals or added chemical additive to case it. Also, you usually need to have water included to help generate any deterioration of the coin. And yes, we might note a very slight greenish or rusty-looking color about the coin or associated with the dirt which was firmly packed around the coin. However, the absolute amount of this gathering of fine particles is not enough to disrupt the electromagnetic field on its own.

Sometimes we recover a copper or clad or silver coins and, due to the depth we located it, and perhaps some apparent discoloration about the object, it is supposed that time has caused a halo about the target that actually magically increased the physical size of the target and made it more 'detectable.' I personally do NOT believe this to be the case, nor have most engineers I have spoken with through the years who have actually given and study to this topic of discussion.

If a target, such as an old large cent, has been laying in an undisturbed position for 150 years, and the site has some very active natural chemicals in the soil or perhaps fertilizer or other material has been used at the site and soaked down to the coin's position, someone might get a good signal and plug the coin out, still firmly encased in a clod. If that clod was to be very gently pried apart and the coin removed leaving only the apparent discoloration still in the impressed coin shape, you can sweep over it all you want without the coin and not get a good upscale positive response. There's just not enough fine particle mass in the discolored soil to disrupt an EMF.

Most of the desired targets we intentionally search for are non-ferrous in make-up. Copper, silver and gold coins and jewelry, thimbles, tokens, buttons, etc.
Yes, we do sometimes find a deeper coin or token or desired find and yes, we might often think that part of out 'good luck' can be credited to an alleged 'halo effect' but consider this.

Think of the beautiful condition Indian Head cents we sometimes find, or see posted by others that are in full or nearly-full detail, clean, blemish-free and have absolutely no discoloring. Then read or remember that they were found at decent depths, such as over 5" to maybe 7, 8, or even 9 honest inches. Undamaged and a good find, even without any supposed 'halo effect.'

How about the dedicated 'Silver Shooters' who concentrate on finding the older silver coins that others have missed be listen for the right signal and getting clean and shiny silver coins where others have searched a lot. There was no 'halo effect' from those coins to be of any benefit.

So, am I saying that there isn't a potential for a 'halo effect' that might influence a target's detection. No, I am only saying it isn't anything that I would assign as a factual happening when it comes to a non-conductive target, such as a coin, because there is no, or virtually very little, actual chemical breakdown of the metal alloy that could significantly cause a detector's response.

However, I do believe we can experience some problems from the massive target decomposition of an iron-based target that can have a bearing on it detectability, both good and bad. Iron is a terrible metal to try and endure a lot of long life when exposed to air, water, and chemical reaction. Often we can find something as simple as an iron nail, or a piece of rusty tin, and old railroad spike, part of an old iron stove, etc., that has been in position for a long, long period of time, with ample exposure to air and water, and to a degree natural or added chemicals, and it shows a lot of deterioration. The vast amount of rusting that is on and about some of these targets actually might cause us to get a greater field disruption and accompanying signal.

So, from time to time I know that we might have to deal with minor 'haloing' about a ferrous object, but it isn't always going to make things respond better. Man-made iron targets are simply things we have formed using a conglomeration of the earth's mineral make-up. Iron. Natural iron in a finely powdered form is not all that conductive, especially when compared to an object made of processed iron that has been formed into a shape that causes more EMF disruption.

Good examples we often discuss are those pesky, crimp-on bottle caps. I have quite an assortment of them in my bottle cap collection and used to have two or three I kept on hand to use in my seminars and other instructions. I have one that is new and has never been crimped on a bottle. I have some modern types that are showing signs of rust and have the thin film type sealer inside. A number of them are in perfect-looking shape, but just solid brown in color from the rusting, and a number of those have small holes in them that have rusted through. Assortments of these give different responses, but I usually saved the best for last.

I'll show some of these old bottle caps to people and let them look them over and then describe to us what they see and what response a few metal detectors will make when the bottle cap is swept past the search coil. Younger fouls are sometimes surprised when the see the older bottle caps I have which still have the cork in the center of the rusted brown cap. It's something they had never seen before.

Then there is the bottle cap which, like a couple of others, just looks a bit different because all the crimp-edge shape is there, but they are almost bubbly on the surface. I have a couple of metal detectors ready to demonstrate and turn them on with a minimum Discriminate level. The ones that are all metal detection capable, and I ask what audio response I might get? Some describe the audio and visual they might see and hear. Then, waving this bottle caps back and forth across the center of the search coil at maybe 4", then 3", then 2", they notice that there is virtually NO response. None! Nothing you would conceive as being a target.

I have had, at two seminars, people in attendance who are quite knowledgeable about such scientific things and smile, just waiting for the answer to the rest in attendance, or they might offer out their opinion. What didn't the obvious appearing bottle cap sound off? Because it was no longer a solid piece of man-made, shaped iron. Instead, it was simply an old bottle cap which, through time and moisture and other natural chemical reaction, had decayed or rusted back to nature.

In short, it was simply a bunch of rust particles that were still clinging together due to other associated stuff. Nothing more, you might say, and an in place 'halo effect' because the entire rusted bottle cap was there, able to be held and observed, but non-responsive. I found three of these old decayed bottle caps just laying on the surface with an assortment of older caps with cork and some without, near the Utah/Nevada border. One of them did finally have a little hole appear in the center and somebody checking it out pinched the edges together a bit too hard and the bottle caps sort of just disintegrated.

Okay, so it wasn't brief. One of these days, a moderator will ban me because I take up too much space, perhaps.

Anyway, to get back to the tough topic of halo effect and good target detection, I don't believe the issue is the presence of a 'halo' or the disruption of a 'halo' during a recovery effort. A 'halo' doesn't just form for good behavior as we might imagine about the head of an Angel. Instead, for any chemical breakdown of the target to occur ... OR ANY CHEMICAL BUILD-UP ON A COIN TO OCCUR ... the target has to settle into a position where it will be firmly in place, for good. The soil much be compacted all about the target. Then, you need to have ample water saturation down to the target's position so that the water can help bring oxygen as well as spur some chemical reaction on or about the target.

Also, another thing that does help us locate some of the older and/or deeper coins and other good targets is hunting during a period when the ground is quite wet. Not just the upper inch or so, but for a 4" coin you need the ground to be well whetted down to saturate the 4"-5" depth. Water is a good electrical conductor and the induced EMF on the surface of a metal object can be somewhat enhanced if the surrounding soil and target are wet.

Please forgive my run-on about my disbelief in any benefit from a supposed 'halo effect' on coin and other non-ferrous targets. We do benefit from enhanced moisture present, at time, but not a haloing. The past 46 years of detecting and analyzing my results and some long target testing has shown it not to be the case. When we do a fresh-bury of a target to test, we will often not get a good response near the maximum depth of a naturally lost and firmly positioned target in undisturbed soil. Just disturbing the ground changes the relationship of the soil, itself, from the adjacent ground matrix.

The same is true when we attempt a recover of a target that sounded goods, but the probing and prying with a screwdriver or especially the plugging and altering of the soil can cause the same change in potential performance. The target might still be there in the same or almost the same position, but it might have been moved or canted, or just the now-disturbed soil ruins our detection performance. It is disturbed ground itself, not a disturbed 'halo.'

Opinions are free, but ample experience can lend support to some opinioned viewpoints.

Monte

 

[usafaviator]

Good data Monte, thanks for posting it!

 

[nw1886]

That was good Monte!!! Guess it all boils down to one's interpretation of "halo effect". Would it be accurate to evaluate it as a response change due to target oxidation/stability factor in a matrix though....and not "enlargement"? I can't tell you how many times I've pulled out heavily oxidized silver.... that was in trash/EMI "free" ground, where my VDI's were heavily skewed....even on shallow targets. (That is, has been, my interpretation of "halo" anyways?)

 

[Aarong81]

I know that from my experience with older, mid 80's, whites that about half the time I would get a strong penny signal at about 4 inches then remove a 3 inch deep plug and lose nearly half the signal. That makes sense if the moist ground helps to conduct the electromagnetic signal. On the flip side, about half the time I would remove a 3 inch deep plug and then the signal increased significantly with out the plug in place. The only reason I can think of that would "increase" the signal after removing the plug is if I did not have the detector ground balanced properly and somehow the ground between the coil and coin masked the signal. Or the possibility that there was iron or hot rock signal in the 'removed' plug which would allow the detector to sound off better without discriminating at the same time. Any other factors involved with the plug removed 'increasing' or 'decreasing' the signal?

 

[Caprock_1964]

Different technology I guess now but back in the early 70's I had a Garrett Hunter that wasn't all that good on depth. I could detect a penny, nickel, or dime at about 3 inches or so and get a knockout signal. Then if you covered that coin back up at the same depth you got not signal at all. I attribute that to a halo effect and so did everyone else.

 

[slingshot]

THIS ONE still has me puzzled though, Monte. Back in the 70's I was using the AH Pro in pulltab discrimination in the local fairgounds. If you remember the Pro, you could adjust the tuner to get max threshhold, and IN THE AIR, you could get a coin at 5" with good headphones. As I was searching I got a somewhat soft signal, but could still get a signal lifting the coil a couple of inches. So my thoughts were ALUMINUM CAN. I thrust my knife to the hilt (6") and got nothing. I cut out the top part of the plug and thrust it to the hilt again and got a loud "clack" as the hilt slightly buried in the ground. At 12" was a beautiful 1800's silver dollar-except for the knife gash in the middle of it. Sorry, but I BELIEVE in halos.

 

[Dustyroundup]

I dont have much to add,
I just wanted to say to MONTE that I am glad he types so long.
I hope they never slow him down.
Its always very informative, and thats what we are here for..
Thanks Monte, for taking the time .

Dusty

 

[Topo]

there is a good well known book for MXT users - MXT EDGE by Jeff Foster, if you like the technical part of detecting it is a must read


play with the programs and coils and stick with what works best for you, the MXT is a great machine

 

[Topo]

there is a good well known book for MXT users - MXT EDGE by Jeff Foster, if you like the technical part of detecting this is a must read


play with the programs and coils and stick with what works best for you, the MXT is a great machine