Modificatios

[3ATHALLLL]

Hi,
WHAT ARE THE SCIENTIFIC PRINCIPLES TO FOLLOW FOR IMPROVING SENSITIVITY OF METAL DETECTOR

[ivconic]

Hi,
WHAT ARE THE SCIENTIFIC PRINCIPLES TO FOLLOW FOR IMPROVING SENSITIVITY OF METAL DETECTOR

Improving S/N ratio.

[Skippy]

Distinguishing ground signal from target signal.

[Sean_Goddard]

Optimising response time of the circuit with respect to target as opposed to ground matrix signals. Or better correlation of probable target responses.

[Nupi]

Sensitive to what and in what conditions and circumstances?

[Dave J.]

Good answers, that about sums it up.

If you've got a commercially produced metal detector, "more sensitivity" is usually a matter of learning how to use the machine to the best advantage depending on the conditions; and in some cases using a larger or smaller searchcoil depending on what specifically you're trying to achieve. There's usually very little if anything to be gained by attempting to modify the circuit design: the original engineer already tried to optimize that within the power consumption and manufacturing cost limitations of that particular product.

In some cases you can jack up the front end gain to get more hots, but then the searchcoil is more likely to go out of balance and ground noise and electrical interference will increase. If you don't understand what you're doing it's best to leave it alone.

[Nupi]

@Dave J.

Excellent overview.

[ivconic]

Good answers, that about sums it up.

If you've got a commercially produced metal detector, "more sensitivity" is usually a matter of learning how to use the machine to the best advantage depending on the conditions; and in some cases using a larger or smaller searchcoil depending on what specifically you're trying to achieve. There's usually very little if anything to be gained by attempting to modify the circuit design: the original engineer already tried to optimize that within the power consumption and manufacturing cost limitations of that particular product.

In some cases you can jack up the front end gain to get more hots, but then the searchcoil is more likely to go out of balance and ground noise and electrical interference will increase. If you don't understand what you're doing it's best to leave it alone.

Nothing to disagree with here!
Pretty correct and clear.
But let's talk hypothetically just for a moment.
For example; Fisher 1265 was made long time ago. At the time there were those chips on market as most suitable for that design.
Today 20-30 years later we have new chips with improved specs.
Now, i wonder what benefits we would possibly gain (or not) if we adapt the same old design with new chips?
I am intentionally mentioning 1265 because i like it and i think it was the "cornerstone" for md tech in those years.

[Nupi]

@ Ivconic
........"within the power consumption and manufacturing cost limitations"..........

[ivconic]

@ Ivconic
........"within the power consumption and manufacturing cost limitations"..........

Yeah... but that's their problem; not our here on these forums!

[Nupi]

Amazingly that still be made issues about power consumption in this age.
Where good rechargeable batteries at every street corner for a small amount can buy.

[Koala]

Nothing to disagree with here!
Pretty correct and clear.
But let's talk hypothetically just for a moment.
For example; Fisher 1265 was made long time ago. At the time there were those chips on market as most suitable for that design.
Today 20-30 years later we have new chips with improved specs.
Now, i wonder what benefits we would possibly gain (or not) if we adapt the same old design with new chips?
I am intentionally mentioning 1265 because i like it and i think it was the "cornerstone" for md tech in those years.

I notice the 1265 selling for quite high prices on eBay for such an old machine.

What makes \ made them so respected.

[Qiaozhi]

I notice the 1265 selling for quite high prices on eBay for such an old machine.

What makes \ made them so respected.

I suspect it's the air test results that made the 1265s famous. They were well known for finding nails at the bottom of very deep holes, and also being quite heavy.

[ivconic]

I suspect it's the air test results that made the 1265s famous. They were well known for finding nails at the bottom of very deep holes, and also being quite heavy.

Air tests... !?
Not really!
I had several in last 25 years. Few 1265s and one 1266.
My personal experiences are quite opposite; it performs much better in real soil than at air tests.
It is very successful "collector" on plowed fields.
Especially for small and smallest bronze and silver coins, also likes gold coins too.
It likes ancient Roman artifacts!
What makes it so special is the behavior, fast and direct response and great accuracy.
...
Maybe not relevant; but let us be reminded that first XP metal detector was designed mostly relying on 1265 design.
XP Adventis Boitier Alu model is actually redesigned and modernized 1265. However; this fact is hidden behind the code in PIC.
XP Adventis Boitier Alu is even today very competitive machine. 1265 also.

[ivconic]