Does Tesoro Eldorado reject all iron???

[Max]

Hi all,
have that (maybe bad) question:
Does Tesoro Eldorado (or other models/brand) reject all iron???

For iron I mean everything from a small 1cm longx1mm diameter nail to a 10'' diameterx1meter water pipe... in disc mode.

So question could be rewritten as: does eldorado (or other models/brand) cancel out ANY iron signal ??? Or something iron could be eventually detected too ???

I refer to VLF/TR discriminating machines only.

Any comment welcome.

Best regards,
Max

[Carl-NC]

I think most all VLF detectors will fail to discriminate large iron targets.

- Carl

[Esteban]

The Wilson VLF 710 eliminates iron as the size of an iron chair, but in this range of discrimination other small no iron targets go out. A good sized coin yet detect in this level, but no at depth.

[Max]

The Wilson VLF 710 eliminates iron as the size of an iron chair, but in this range of discrimination other small no iron targets go out. A good sized coin yet detect in this level, but no at depth.

Hi Esteban,
so it can't be used as coinshooter detector. But how it can reject objects like an iron chair ? Which coil it uses ?

Best regards,
Max

[Esteban]

Hi

Can detect coins, but no at depth in high discriminative level, and iron objects can be discriminated. This detector is of the 80's, maybe 1984. I have one and I'm tracing the schematic, slowly. All ICs no "rare". Coils are concentric, no shielded, only graphite paint in inferior coil housing. ALL RESISTORS are 1%, except 2 100 K 5%. There are very rare values as 29.21 K, 47.5 K, 10.215 K (these values are indicatives), etc., some of these, all measures with digital tester, no errors in values. Use 9 volts batteries (3), one for audio.

Let me some time and I'll post parts and photos. I make a hardzarous job for to take transparent digital photos in clear days, etc.

This detector we use in the most high discriminative mode for to be sure and break a wall for to find 58 silver coins (I post in coil sections the photos and list of coins). This quantity of coin was detected very well in high discriminative mode. Is a delicate detector in the terrain regarding to mantain the same position respect the soil, don't move much, etc.

[Unregistered]

Hi MAX

Hi all,

Any comment welcome.

Best regards,
Max

Hi MAX
THE Twin Loop Detetcor is nice if we replace the IC with LM318 or NE5534 and changing the circuitry around it to get a positive feedback for feed back, removing the caps etc, and using only a single coil. Some one should try for dual coil with LM318 or NE5524A
Why didnt they( Robert and David) use a capacitor at pin5 to ground ( Modulation Pin) for Ne555's ???

[ivconic]

So far as i experienced, everyone of 50-60 different brands failed to fully discriminate large iron objects.
Famous "horse shoe" is best example of this.
All types of medium and large "hammered" iron items are hard to be discriminated, if not impossible.
I am not talking only about hand mades, i am reffering this mostly to top models from few leading manufacturers.
Pay attention on word "hammered"! Cose i have cases of fully discriminated large iron items made from ordinary effused iron - not hammered.
Why is that so? Dont know yet?


Yet..small iron items like rusty nails and simillar are very easy fully discriminated by TGSL handmade. Not even a sound on those.

[ivconic]

Example

This video is not made in this purposes..yet, colaterally you can see discrimination effect on TGSL...

[Max]

So far as i experienced, everyone of 50-60 different brands failed to fully discriminate large iron objects.
Famous "horse shoe" is best example of this.
All types of medium and large "hammered" iron items are hard to be discriminated, if not impossible.
I am not talking only about hand mades, i am reffering this mostly to top models from few leading manufacturers.
Pay attention on word "hammered"! Cose i have cases of fully discriminated large iron items made from ordinary effused iron - not hammered.
Why is that so? Dont know yet?


Yet..small iron items like rusty nails and simillar are very easy fully discriminated by TGSL handmade. Not even a sound on those.

Hi,
yes I agree: hammered stuff (not only iron) have different behaviour than not hammered things like direct fusion kind etc

I noticed too that very old iron things hammered are so compact that they rust just on surface in hundreds (or thousands) years!

I think also the problem is related to composition: often we think that some old stuff is iron... but it isn't pure iron stuff... it's very rare.

That's cause in old metallurgy there was the habit of mixing e.g. carbon powder and grains with iron minerals and then cooking all in the oven... thus resulting in a melt alloy of iron-carbon particles ...

If the process is done right way the alloy will be very resistant and could survive in worse soil for 4000-5000 years!

It's kind of steel ... not inox of course but so compact and strong that rust just on surface and appears from dark red/brown to black. I found also a dark green kind.

The ancient peoples known about steel well before modern age.... just under the middle-age there was a dispersion of most metallurgic techniques then redescovered in next centuries and so arrived to us as steel etc

The evolution of e.g. armours is clear example of what I report here... in middle-age there were just iron made stuff... then steel technolgies changed all like happened in ancient times many centuries before.

I have a big set of volumes (history of technology) that explain how some ancient technologies were misunderstud or then lost and then "discovered" again and again in different places after long time, some by case others cause of ancient books/documents stored in abbeys libraries etc during the middle-age.

Kind regards,
Max

[ivconic]

"...often we think that some old stuff is iron... but it isn't pure iron stuff... it's very rare...."

I think that is the right answer.