Real Metal Detectors

[Max]

Hi,

I though all PI´s had a big capacitor to supply the very hight impulse current.
I didn´t notice the red logo before.?? interesting.

Michael, did you try to hold one or other or both buttons while powering on the detector?
sometimes software information or setup appears this way.but proceed with caution...
Regards,
Fred.

Hi,
often the capacitor there in common PI is employed as tank of charge that will supply extra current at switch-on but this design is probably different cause capacitor is very large , 10000uF is something not so easy to be found unless in top depth PI usually.

Is it just to average e.g. supply rail and give extra current at switch-on ? Possible... but how much probable it's so?

I think it could be like in some good ones... that use the avalanche device just after the right amount of charge is stored into the cap... they provide always same energy to coil... no matter of battery status or temperature at mosfet... that's why they are cool devices and exibit higher S/N.

Kind regards,
Max

[Fred]

I think it could be like in some good ones... that use the avalanche device just after the right amount of charge is stored into the cap... they provide always same energy to coil... no matter of battery status or temperature at mosfet... that's why they are cool devices and exibit higher S/N.

Kind regards,
Max

Ahh ok i understand now.Yes , interesting.Only 25V , but the important is not the power, just the precision .
Anyway there is probably some sort of auto-setup of transmited power,as Michael says he can run with it once calibrated.

Regards,
Fred.

[Berti]

MDL 8500 I think was made by any expert in this field.
It doesn't look manufactured.

He has named it MDL 8550 for any reason so we have to find this man if we want another copy.

Any other recommended equipment for buried gold do you know?
Of course if you have used it yourself.



Regards Robert

[michael]

Hi, thank you Max for your good info.
about the red logo!!!! as I know there is no logo.
Max, Fred, what have you seen that I'm ignorant about?
if tell the red part at right of front panel, it's battery ID, push it to show the battery voltage nothing else. Fred I have never tried pushing keys at same time. maybe do it at first time in field as now the cable is not here (is hidden in that area) and device needs the cable to be turned on.

Max you pointed to Pulse star II big cap, I can tell you our first PI(Luminous) is like Pulse star in power
http://thunting.com/geotech/forums/s...t=11799&page=1 and
http://thunting.com/geotech/forums/s...t=11799&page=2

the latest location where we detected, with our Luminous can be detected from 10-15 meters, whereas don't see any high capacity Cap inside Luminous.
but with MDL easily is detectable from 80-90 meters; hardly incredible.
another thing I have seen inside "DTI Genesis" it has also one 10000uf Cap, but never could detect our test target despite other kind of PIs.
Can we conclude in MDL all stuffs have been calibrated and set as the best?

[ivconic]

Michael as i recall once you stated that your terrains are actually deserts? Right? Sand,sand and nothing but the sand. Right.
If that is true than any detector will do nice job there. Even Pulse Star II.
Other hand terrains like we have here are not that easy to be searched with every possible detector. For example, same Pulse Star II turned to be totally unuseable on these terrains. A crap with huge C capital!
Same thing with Lorenz. Crap.
So...i personally have doubts that MDL... is better at all and more useable than PSII and others.
Ordinary PI with strong output will do excellent job in such elementary soils like sand.
I dont think MDL is something special. Most probably it is ordinary PI with more amplificated output and more current drain. It push several amperes in coil and kill every possible bug in sand!
You should take DFX,Relic Hawk and Nautilus (i'll take Carl's word on this one) and test them and compare with MDL.. You will realize those are even better!

I am not trying to deny you thrill, only i always feel strong repulse against simillar bombastic stories not supported even with one provable fact.
To me personally, MDL's enclosure reminds me mostly on my old,obsolete adsl router. Stickers and prints on it are so low profile, could be done even by some children.
What we have here? Few fragments of some photo and huge, grease, bombastic story....again of some nonhuman allmighty device!?
"Intel inside"....!? C'mon...it is stupid joke!Dont you see that?!
You should open enclosure and take panoramic shot of it. Also take shots in details like Eclipse did with Musketeer.
Than we can have more details to examine and think about.
So far we got only enigma...most probably fairy tale.

[Qiaozhi]

Most probably it is ordinary PI with more amplificated output and more current drain. It push several amperes in coil and kill every possible bug in sand!

Actually this is an interesting point.
Michael - what is the battery for this detector? What voltage, and how many ampere-hour capacity? And - most importantly - how long can you detect with this battery?

[michael]

Michael as i recall once you stated that your terrains are actually deserts? Right? Sand,sand and nothing but the sand. Right.
If that is true than any detector will do nice job there. Even Pulse Star II.
Other hand terrains like we have here are not that easy to be searched with every possible detector. For example, same Pulse Star II turned to be totally unuseable on these terrains. A crap with huge C capital!
Same thing with Lorenz. Crap.
So...i personally have doubts that MDL... is better at all and more useable than PSII and others.
Ordinary PI with strong output will do excellent job in such elementary soils like sand.
I dont think MDL is something special. Most probably it is ordinary PI with more amplificated output and more current drain. It push several amperes in coil and kill every possible bug in sand!
You should take DFX,Relic Hawk and Nautilus (i'll take Carl's word on this one) and test them and compare with MDL.. You will realize those are even better!

I am not trying to deny you thrill, only i always feel strong repulse against simillar bombastic stories not supported even with one provable fact.
To me personally, MDL's enclosure reminds me mostly on my old,obsolete adsl router. Stickers and prints on it are so low profile, could be done even by some children.
What we have here? Few fragments of some photo and huge, grease, bombastic story....again of some nonhuman allmighty device!?
"Intel inside"....!? C'mon...it is stupid joke!Dont you see that?!
You should open enclosure and take panoramic shot of it. Also take shots in details like Eclipse did with Musketeer.
Than we can have more details to examine and think about.
So far we got only enigma...most probably fairy tale.

Hi.
our terrains are the worst soils there can never find sand, never, mostly mountainous, rocky places or hard soils which can hardly pick it. somewhere soil is like cement such the last place found by MDL, was very hard that at
2 nigh working we could go down only 150 Cm. it needs hilty digger. where I've pointed to sandy places??!!!
about pulse starII or even Lorenze, admittedly are somehow good detectors, but in comparison with MDL are highly weak and unstable with drifting or decreasing in signal intensity. theoretically is simple, yes with very high amplified output signal, but why other makers, producers have not
made such thing by this time, if is simple?
we've inserted our test target in such places and filled over it every other layer soil and big stones to make it very similar to a real buried treasure.
our Luminous, Pulse star II and even Lorenze detect it hardly by force
and when you go searching around and come back over test target place, occasionally detect it(drifting) but, MDL; either hit it very strongly and can go search around for hectares and come back, detects it as same first with same intensity.
then you are comparing it with hobbies like DFX, Relic Hawk and Nautilus ?? no, unfair comparison.
let me tell you one thing; with MDL, we became 100% sure that some places are entirely without any treasure and we closed their dossier forever. every time we got new detector took it in these places now we are sure there is no treasure.
about new place found by this small naughty (MDL) there was a big project since 10 years ago that one team started they used back-hoes and dug about 7 very deep well (a dowsing work) to find the location of this treasure.
of course the natives were ignorant, but we were suspicious from first to their project purpose. 5 years ago left there disappointedly.
last year I had searched there (like other places) by FG80,got no signal.
to year we went there and searched, some signal appeared from 80-90 meters of target, with tracking the right direction(towards the increasing signal) we got that signal intensity increasing progressively or logarithmically; we all were shocked.
at last we found point at 50 meters beyond their nearest dug well !!!!!!!!!!! in a place that without MDL not only we but also not even the most expert teams would never guess the location.
it approved they have been looking for based on treasure mapbut most of signs on ground had been removed by nature or people during centuries. only mountains and some hills remained, then were baffled for exact point.
now tell is like DFX, Relic Hawk and Nautilus ???

Actually this is an interesting point.
Michael - what is the battery for this detector? What voltage, and how many ampere-hour capacity? And - most importantly - how long can you detect with this battery?

The battery; it uses only external feeding with 12V battery. The longest it lasted was less than 4 hours with entire full 5 A.

[ivconic]

"..our terrains are the worst soils there can never find sand, never, mostly mountainous,
rocky places or hard soils which can hardly pick it..."
Is that so? Sorry than, i confused you with somebody else!?
"..every time we got new detector took it in these places now we are sure there is no
treasure..."
Eh, that is what i also do every time. Whenever new machine appears, i use to visit same
places and check again.
Ok...could be some extra low noise PI. Yet it is not extra powered since you said it uses
12V battery only. I didnt understand about those 5 A? Is the battery labeled as 5A or it
draws 5A during working?
Cose, in first case it would be pretty ordinary PI detector, but in second case it would be
real beast!
So few datas you gave here.
Yes...enclosure reminds me on other device, but also could remind on PPD. Simillar design.

And last...do not disprage DFX,RH and Nautilus... no such thing as "professional" and "amatuer"
metal detectors. There are detectors with different purposes only.
DFX could be highly professional...and also highly amateur..depends of a user...

[Qiaozhi]

The battery; it uses only external feeding with 12V battery. The longest it lasted was less than 4 hours with entire full 5 A.

I didnt understand about those 5 A? Is the battery labeled as 5A or it draws 5A during working?

Michael - does the label on the battery say 5Ah, and is it a lead-acid type?
If so, this is a fairly large battery to carry around. And with only 4 hours operation, it must be using an average of 1.25A when in use.

[michael]

Hi, yes, the battery is 5Ah SLA, I fasten it with belt on waist for long time searching it causes little pain on waist, then the central MDL box is highly light and never make any problem on neck despite other kind of PIs.
oh, there is only 2 problem with MDL;
1- for its' highly powerful induced magnetic field, sometimes it causes a little headache on the operator inside loop(frame) who carries the 2x2m frame. I follow him with 5 meters distance( interface cable length) from back.
then we have to rest for 20-30 minutes after 1 hour searching to decrease the safety risk as far as possible.
BTw; from first we turn it on never off it until the battery is OK to keep the board warm and at best work efficiency.
2- as you know all PI's react to "Viscous magnetized" which are man-made (some kind of ancient bricks or heated mud-bricks); at least what we have found by this time was so.
The MDL is not an exception and detects them proportionally clear.
but with experience we found out that the size of a big viscous magnetized is like a small piece of metal(about 2m x 2m or 3m) and the signal intensity never goes upper than number 50.
for this reason we disregard all such signals that maybe are for small precious metals then lose them.
we have found many of such locations, but no more digging, just marked them all, need a good reliable detector for superficial small objects which be capable to penetrate to hot-rocks or "Viscous magnetized" and hit the metal (something like Minelab GP series). then later we probably buy one.
do you have any better offer for this purpose?
about the latest location when reach to about 20-30 meters from it ,MDL terribly overloads to the maximum number; 163.
with 5-6 time retuning(resetting or nulling ) it let us to approach the hottest point, but again the signal goes up to number 120 then we could pinpoint the strongest point, whereas you know there we don't have a point, it's a real treasury obviously in huge size maybe a room in 5m x 5m. we searched there with other MDs, no junk metal at surface.
anyway MDL is a terrible masterpiece, a feat of Detectors world that worthies to look for it with all of your potentialities and please tell me if found.
here you see our dug hole to 150 Cm. surely isn't sandy. caused bad blisters on our palms.

[Max]

Hi, yes, the battery is 5Ah SLA, I fasten it with belt on waist for long time searching it causes little pain on waist, then the central MDL box is highly light and never make any problem on neck despite other kind of PIs.
oh, there is only 2 problem with MDL;
1- for its' highly powerful induced magnetic field, sometimes it causes a little headache on the operator inside loop(frame) who carries the 2x2m frame. I follow him with 5 meters distance( interface cable length) from back.
then we have to rest for 20-30 minutes after 1 hour searching to decrease the safety risk as far as possible.
BTw; from first we turn it on never off it until the battery is OK to keep the board warm and at best work efficiency.
2- as you know all PI's react to "Viscous magnetized" which are man-made (some kind of ancient bricks or heated mud-bricks); at least what we have found by this time was so.
The MDL is not an exception and detects them proportionally clear.
but with experience we found out that the size of a big viscous magnetized is like a small piece of metal(about 2m x 2m or 3m) and the signal intensity never goes upper than number 50.
for this reason we disregard all such signals that maybe are for small precious metals then lose them.
we have found many of such locations, but no more digging, just marked them all, need a good reliable detector for superficial small objects which be capable to penetrate to hot-rocks or "Viscous magnetized" and hit the metal (something like Minelab GP series). then later we probably buy one.
do you have any better offer for this purpose?
about the latest location when reach to about 20-30 meters from it ,MDL terribly overloads to the maximum number; 163.
with 5-6 time retuning(resetting or nulling ) it let us to approach the hottest point, but again the signal goes up to number 120 then we could pinpoint the strongest point, whereas you know there we don't have a point, it's a real treasury obviously in huge size maybe a room in 5m x 5m. we searched there with other MDs, no junk metal at surface.
anyway MDL is a terrible masterpiece, a feat of Detectors world that worthies to look for it with all of your potentialities and please tell me if found.
here you see our dug hole to 150 Cm. surely isn't sandy. caused bad blisters on our palms.

Hi,
if the current is around 1.25A average well.... it's a big beast for sure. When doing with some Eric Foster's thing you could get near 0.5A average... but 1.25 is incredibly hi current... that probably means you get something 15-20amp peak current at each TX pulse.

Now... this estimate is very approximate... cause we don't know e.g. TX duty factor and pulse durations... nor we know about coil details... but it's likely you have such power on coil, but it's realist expectation from such an high current drain.

I think even more now device need the 10000uF tank capacitor to hold charge... it then abruptly deliver to coil from there...

This could also explain why a 105° is employed: moving such large currents, even in low ESR conditions (good cap) would mean LARGE heat transfer to the elctrolite... that could "boil" and dry... easy at common 85° devices... and trigger, at some point, some big blast inside the BOX.

I suggest you test for heat generated there... look for temperature. Is it higher than 65° C externally... after say 10minutes from start ? Do you know about ?

Kind regards,
Max

[hung]

Hi Michael!

You told me sometime ago in a message about a place where the FG80 beeped and your team proceeded digging a large hole. Did your MDL also signaled this place or not? Whatever happened to this site?

You must remember that cave's treasure case in the end of 2006 right?
I was using the FG80 at the time and it gave a very clear signal in a particular spot on the wall. The signal lasted according to the extent I moved the detector horizontally. I marked that length on the wall with chalk. Of course I had previously detected the spot from outside, about 75m away or more. Inside the cave I reduced sensitivity to be able to pinpoint it.

Later we took a conventional MD there and it signaled exactly in the area marked with chalk on the wall, which corresponded to the mass length hidden behind it.
Did you try to use the MDL lengthwise in the spot the FG80 marked? Of course the MDL can only be used after the FG80 or you will completely ruin the electrostatic/ionic field in the spot.

PS. Nice hole pic. Looks very professionally dug.

[Fred]

I think the value of 1.25 amps is a bit generous, as we cannot consider a 100% depletion of the battery.
Something between 60 to 80% of this value , depending of circuit ,or between .75 to 1A. That is a lot anyway.
regards,
Fred.

[michael]

I suggest you test for heat generated there... look for temperature. Is it higher than 65° C externally... after say 10minutes from start ? Do you know about ?

Hi, no, I don't know about and don't think can dare do it as I try not to open it as near as possible.

Hi Michael!

You told me sometime ago in a message about a place where the FG80 beeped and your team proceeded digging a large hole. Did your MDL also signaled this place or not? Whatever happened to this site?

You must remember that cave's treasure case in the end of 2006 right?
I was using the FG80 at the time and it gave a very clear signal in a particular spot on the wall. The signal lasted according to the extent I moved the detector horizontally. I marked that length on the wall with chalk. Of course I had previously detected the spot from outside, about 75m away or more. Inside the cave I reduced sensitivity to be able to pinpoint it.

Later we took a conventional MD there and it signaled exactly in the area marked with chalk on the wall, which corresponded to the mass length hidden behind it.
Did you try to use the MDL lengthwise in the spot the FG80 marked? Of course the MDL can only be used after the FG80 or you will completely ruin the electrostatic/ionic field in the spot.

PS. Nice hole pic. Looks very professionally dug.

Hi Hung, no, it was more than one year ago at march.2007 and in another area. they went down up to 12 meters nothing found, yes, it was the first and the only noticeable signal with FG80 from 10-12 meters distance
with 1 meters signal width ( I thought lest be an ON TV buried in that remote wilderness area that signal after 10 times repeating gradually faded out.
at that time we didn't have MDL, although the place was entirely unworkable for any kind of MD or GPRs. the guys had a map of big treasury. it's about 7 months we own it and only for 2 latest month we are working intensively.
after that we never get any noticeable signal with FG80.

I scanned this latest place where I'm pointing with FG80 step by step at best weather conditions, and I remember I passed exactly over this point, but no signal, we regarded this place free of treasure. after nailing MDL we searched most of our places after getting no signal, I offered to search this area again with MDL, it held our hands and pulled to the location. If any treasure be excavated can conclude certainly FG80 is useless at least for very deep targets.

[1843]

Hi michael,
Can't you measure the frequency and pulse length of your PI?

Regards
1843