I believe it has to do with this...
Sensitivity on the Explorer does not equate with a stronger transmit signal as is the case with 99% of machines, rather...it increases the number of progressively smaller signals that are allowed through to be processed in the first place. If the ground is mineralized to a decent degree or there are small fine pieces of iron around...or even EMI....the test target gets either disced out if there’s disc applied because it gets “down averaged” or the relatively weak deep Merc may not be big enough to return a sufficient signal through the “noise”. On my Explorer 2 I can get to a manual Sensitivity of 23 before the deeper targets start breaking up in most of my sites, which are places with a lot of bits of iron such as nails and pieces of nails.
I do not see this phenomena in an air test, only when in the ground do I see it. I ALWAYS preach modest sensitivity to all who will listen. Turning up the Sensitivity to bull your way through troubled ground is a fools errand, one I have run many times in my earlier days of detecting.
I guess i'm a bull but a fool i'm not Let's take sensitivity it's just another form of disc the less you use the less targets are heard which targets are the first to go well the deeper and weaker targets .
I run the 6 inch head for good reason to much thrash for a larger coil when you adjust sensitivity and adjust to high your #s and ids go all over the place what happened (YOUR PROCESSOR CAN"T KEEP UP) The 6 inch coil rarely has this problem i can run at full boar 95 percent of the time and the detector is stable
switch to stock coil same place sensitivity has to be backed down to 21 to 23 so what did you just do you got rid of all those weaker signals the deeper ones you want to hear .
That stock coil is seeing 3 to 4 more targets than the 6 and 3 to 4 times more dirt how in the h$$$ are you going to find anything in a thrash place not only that but you have to reduce sensitivity there by loosing those deeper whispers.
Well you say a big coil well go deeper than a small coil true but it's geared for larger targets not small returns as the 6 .
Then again you can dig a 22 short casing at 6 inches deep with a big coil but ad a little thrash and it's gone same as a dime.
I have tested and tested targets using less sensitivity what i found is yes if you lower sensitivity some targets well sound better but i would still have dug them using max sensitivity the target id #s well jump a little and will not be as stable but if you know your machine you know what to dig and what to not .
Then again if i use this setting for sensitivity lower i would be missing all the deeper weaker returns .
Then again it's very rare where i hunt that i'm overdriving the 6 the 11 where i hunt i can overdrive it everywhere which means the processor just can't keep up and sensitivity has to be reduced . When i say processor it is processing emi dirt and the targets in the ground .
Some say the 6 just can't go deep well you just haven't used it enough here a example of a thrash infested place big coil 10 targets under coil 6 inch coil 3 targets under coil my ground goes though freeze thaw cycle every year all it takes is one of the targets to change position and the 6 well light up the target that was masked not so with the 11 inch coil you still have the 10 other targets under the coil.
As i said before a bull yes a fool no. sube