Here’s is a link.
http://nevada-outback-gems.com/MXT_files/the_mxt_faq2.htm
Very good thread here with info.
https://metaldetectingforum.com/showthread.php?t=15663
I am not done here yet.
Standby.
Okay, coins ideally will read a certain number but they can fluctuate a bit too depending.
You when hunting trashier sites may indeed get clean hits with ideal (per coin) ID readings.
Here is something to keep in mind though.
And you can do yourown test to see the effects of colocated coin and say foil, pull tab, rings, etc.
You see if you have 2 say dimes near one another, this will likely not keep you from hearing one of the dimes with correct to more correct ID.
But what if a dime is near say a pice of foil?
What then?
It is very possible your detector may indeed give more of an average ID, meaning the foil is being process along with the dime as one target and reports lower than ideal for the dime.
The size of the foil, how it is orientated depthnwise in relation to a dime can make the effects more or less as far how how much dime ID id effected.
Some good experiments to do are.
Sweep dime solo.
Place nickel and dime near one another and sweep and note meter readings.
Place foil near dime and do the same.
Place beaver tail near dime and sweep.
Adjust spacing between the coin and other items to see effects on ID.
You can use other coins too.
A gold ring near a silver dime, very possible a detecrosits who is cherry picking might just walk right by thinking junk. ID too high to be gold generally and too low to be say copper or silver coin.
You as a detectorists while detecting areas where it is not logical, or really possible to dig every signal period. You can do the following.
You can set yourself a goal. Realizing ID of good items like higher conductive coins will indeed have their ID pulled down. So establish yourself a threshold lower than actual coin ID and use this lower ID provided on detected targets as Your guide to dig or not. Is this system full proof? No. But sure beats digging all, and most likely most will indeed be junk nonferous.
The MXT running at 14khz is not the best freq to use to hunt modern trash sites.
Better Detectors to use use lower freqs like in the 5khz range. This lower frequency will tend not to see the lower conductors as well, and also will not average higher conductors and lower conductors as low vs real ID of higher conductive coin.
Detectors like Nokta Impact.
Makro Multi Kruzer.
Minelab fbs detector like explores and Etrac and CTX.
Minelab Equinox.
White’s Vx3/V3i
Rutus Alter 71
There may be more.
A small coil like 4x6, 5”, 6” can help too even if using the detectors I list above.
Coils sweep speed can be a factor too. But remember there is only so much slower coil sweep can do to help locate a higher conductive targrt in a sea of trash.
Recovery speed set faster can help.
Pinpoint like you said can be a waste of time.
I hope this helps.