F70 threshold/sens combinations Digger27?

Yes, it sure can make a difference in the depth dept. but it also affects the amount of noise and chatter we get and sometimes the tonal qualities on some tone choices.
When not using my blast through all metal maxed out settings I usually hunt in disc with the thresh in negative numbers at -2 to -6 so far and get decently deep for my needs but the soil I hunt in never gives up much depth anyway.
I can get to my targeted 6-8" area, and I worked hard to get to this area for months, but I am hitting targets in that range with thresh as low as -3 to -4.
Using all metal, sense into the 90's and thresh at +9 I haven't been able to get any deeper and find anything good that I couldn't pick up in disc...so far.

When I use 3-4H tones I never get into positive thresh numbers...it skews the signals into some weird squeaky sounding tones that I don't like to listen to.
In monotone this higher thresh does not have much affect on that tone sound but I still usually keep it in the negative numbers for noise reduction...but I might need to rethink that.
I will endeavor to push that thresh higher in monotone for the next few hunts...maybe it might be better and deeper, who knows.

Supposedly really low thresh cuts out tiny targets but I have found some really, really small stuff even at -6...again not really deep.


Here is a vid with an F70 hitting an 8" coin with boost and a sense setting of 1 but the thresh needed to be at least at +4 to do it.



Many say all the time the thresh and the sense have a very close relationship, turning one up and one down can have all kinds of effects on noise, depth, and signals.
It is possible to have completely different settings and still hit optimal performance benchmarks I suppose...high sense and low thresh vs. low sense and high thresh.
It seems you have proved this somewhat in your observations.

This is why I experiment so much and never stop.
I do have favorite settings that I know work for me but I still love to tweak...you never know what that next little change in any setting might do.

Just push your rig to the highest settings that you can stand, noise wise, and see what happens.
I usually do and got comfortable listening to a lot of chatter sometimes and learned to deal with it.
Air tests and real life results might be different but you just gotta get out there and try new things and observe.

In your NC. soil, which I believe might be some of the best in the country, pushing your rig to high levels might hold great advantages.

In great soil in Kansas I could hit solid targets easily at the 9-10" level and a few times even at 12" or more with sense in the mid 80's to low 90's and thresh in the low negative numbers and no boost in the real world so take your air testing results with a grain of salt and dig a few deeper targets with thresh in all ranges for the best real world data.

Hey, thanks for the great reply! I just watched your video...did you try raising your sens when you had the threshold in the negative range on that quarter? In my airtest on a dime I got 9" with a clear, clean tone setting the sens at 90 and the thresh at -1 which was about the same as when I bumped the thresh up to +1. Maybe just a slight increase in depth at +1, but not much. I can see I'll have to plant some coins out in the yard and try some more experimenting with different settings. Thanks again!

NCtoad said:

Hey, thanks for the great reply! I just watched your video...did you try raising your sens when you had the threshold in the negative range on that quarter? In my airtest on a dime I got 9" with a clear, clean tone setting the sens at 90 and the thresh at -1 which was about the same as when I bumped the thresh up to +1. Maybe just a slight increase in depth at +1, but not much. I can see I'll have to plant some coins out in the yard and try some more experimenting with different settings. Thanks again!

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I didn't do that vid but another member here did.
I rarely air test anything and I never had a place to put in a test garden, I would rather just find stuff in the wild and tweak my settings from there.

Ok, I just went out and buried a zinc penny at 6", a clad dime at 7" and a clad quarter at 8". I can't seem to get any tone whatsoever on the quarter no matter what mode (disc or at) or any combination of sens and thresh settings. Same thing with the dime, but maybe a very slight tone on some settings. On the penny I can get a decent tone with mid sens and mid high thresh settings, however the numbers are very low in the iron range and jump a lot. Is this normal? My ground balance number is 88 if that makes any difference and I'm using the stock concentric coil. On another note the reason I'm asking all this is that all the clad I've found (19.95 worth) has been at 4" or less. Thanks.

NCtoad said:

Ok, I just went out and buried a zinc penny at 6", a clad dime at 7" and a clad quarter at 8". I can't seem to get any tone whatsoever on the quarter no matter what mode (disc or at) or any combination of sens and thresh settings. Same thing with the dime, but maybe a very slight tone on some settings. On the penny I can get a decent tone with mid sens and mid high thresh settings, however the numbers are very low in the iron range and jump a lot. Is this normal? My ground balance number is 88 if that makes any difference and I'm using the stock concentric coil. On another note the reason I'm asking all this is that all the clad I've found (19.95 worth) has been at 4" or less. Thanks.

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Not normal sounding to me.
88 is really high for a GB number but still..

Have you done a reset lately?

I assume all metal should get down here pretty good, I could get to 10" in really great soil with that coil but maybe your soil is the problem...plus freshly dug dirt is not exactly the greatest matrix to test in.
The big DD coil might get deeper, any DD coil might for that matter.
Try the reset and get back with results.

DIGGER27 said:

Not normal sounding to me.
88 is really high for a GB number but still..

Have you done a reset lately?

I assume all metal should get down here pretty good, I could get to 10" in really great soil with that coil but maybe your soil is the problem...plus freshly dug dirt is not exactly the greatest matrix to test in.
The big DD coil might get deeper, any DD coil might for that matter.
Try the reset and get back with results.

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I did do a factory reset and tried the various combinations after the initial runs. The other thing is the ground is really, really dry here ...won't even clump together because lack of rain. Would dry soil make it worse?

Moist is better for depth, better conductivity.
We all need rain, I can't dig more than a couple of inches in my dry stuff right now.

Same boat

NCtoad said:

Ok, I just went out and buried a zinc penny at 6", a clad dime at 7" and a clad quarter at 8". I can't seem to get any tone whatsoever on the quarter no matter what mode (disc or at) or any combination of sens and thresh settings. Same thing with the dime, but maybe a very slight tone on some settings. On the penny I can get a decent tone with mid sens and mid high thresh settings, however the numbers are very low in the iron range and jump a lot. Is this normal? My ground balance number is 88 if that makes any difference and I'm using the stock concentric coil. On another note the reason I'm asking all this is that all the clad I've found (19.95 worth) has been at 4" or less. Thanks.

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NCtoad,

If it makes you feel better I had identicle problems today. After getting 5" of rain the last 3 days I went out for a hunt. I buried several brass, copper, tin, silver, and gold coins in gopher hole mounds. I got very choppy signals in Disc and All Metals. I had a very frustrating day. It seems like every square nail blows my ear drums out but anything of interest gives a broken and vague blip on the screen. I'm running a new F75 and it's proving quite the learning curve.

Think of the threshold as an open door... further into positive threshold, further open the door, and more targets detected

Close the door, use a negative thresh, and less and less targets, smaller targets are detected, thus giving you a quieter machine

On the f5, I ran a high gain, low thresh and had a very stable machine.

Negative thresh in trashy areas will quiet your machine down, its really that simple

CaveCitySlayer said:

NCtoad,

If it makes you feel better I had identicle problems today. After getting 5" of rain the last 3 days I went out for a hunt. I buried several brass, copper, tin, silver, and gold coins in gopher hole mounds. I got very choppy signals in Disc and All Metals. I had a very frustrating day. It seems like every square nail blows my ear drums out but anything of interest gives a broken and vague blip on the screen. I'm running a new F75 and it's proving quite the learning curve.

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I think it's the very dry, hard-packed red clay soil I buried the coins in. As I filled in each hole over the coins, I packed the soil back in so the soil is compacted really well. The next day I tried burying a nickle in an old topsoil area that I had tilled up 4 or 5 weeks ago. Since we've had very, very little rain here the soil in this area is dry and very loose. So I buried the nickel at about 5 1/2 inches and had no problem what so ever picking it up on all kinds of thresh, sens combinations. I think I even picked it up with sens on 1 and thresh on 9. I also tried an area off to the side of the topsoil where there was red clay (very loosely packed) and got the same results at about the same depth. In fact on the higher sens and thresh settings I was getting a strong tone with the coil 4-5 inches above the ground. Ground balance was reading mid 80's on both holes. The only thing that's weird is all the readings came up in the high 80's to low 90's...nothing read in the 30-31 nickle range which is what I've been finding all my nickles at. Just need to keep practicing with this and trying different settings.

NCtoad said:

I think it's the very dry, hard-packed red clay soil I buried the coins in. As I filled in each hole over the coins, I packed the soil back in so the soil is compacted really well. The next day I tried burying a nickle in an old topsoil area that I had tilled up 4 or 5 weeks ago. Since we've had very, very little rain here the soil in this area is dry and very loose. So I buried the nickel at about 5 1/2 inches and had no problem what so ever picking it up on all kinds of thresh, sens combinations. I think I even picked it up with sens on 1 and thresh on 9. I also tried an area off to the side of the topsoil where there was red clay (very loosely packed) and got the same results at about the same depth. In fact on the higher sens and thresh settings I was getting a strong tone with the coil 4-5 inches above the ground. Ground balance was reading mid 80's on both holes. The only thing that's weird is all the readings came up in the high 80's to low 90's...nothing read in the 30-31 nickle range which is what I've been finding all my nickles at. Just need to keep practicing with this and trying different settings.

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Here is my experience with nickels here in the SE in my soil.
Nothing like this came close when I hunted in Kansas soil...ever.
Post #4...

http://www.treasurenet.com/forums/tesoro/518449-eldorado-nickels.html#post5160293


This high number behavior is not weird, strange or odd...this classic up averaging behavior is programmed into the T2/F70/F75 platform and probably a few others.
Use this feature...and I do believe it is a great feature, to your advantage and you will not believe how much you will find deeper that others have missed because they relied on standard and common VDI information and behavior when hunting around iron or in mineralized soil.
Not just relating to nickels but all coins and other good targets.
I have, I now own all kinds of bucket list items especially coins that I have found deeper in my soil that came from totally hammered and long ago given up on sites because I learned to understand this and use it to my advantage.

Evidently you have that red clay soil in your area but it appears even the black stuff seems to have a good amount of iron mixed in like mine does.
That 88 GB number is quite a clue I can see now.
Even in my bad stuff I have rarely reached nor have I ever gone above the high 70's to low 80's.

Go back and read the info I put down in post #6 in this thread...again.
This will explain all that you have experienced on this test and my way and method of dealing with it.
http://metaldetectingforum.com/showthread.php?p=2662738#post2662738

I needed to learn new indicators, new behavior patterns, different settings...a whole new language and methods to hunt so successfully in my very difficult soil at deeper areas to recognize the better targets so many have missed for decades.
It took time but that was time well spent and it looks like your soil is not quite as good as I thought at first but a lot more like mine than I believed possible.
If it is this is both a blessing and a curse for you.
A curse because mineralization this high really limits depth no matter what VLF machine you use with any coil.
A blessing because even though it does this there is still a layer of target rich dirt from about the 5-8" level that you can still reach that holds a huge amount of severely masked and non normal totally skewed signals that can be recognized and recovered that others never suspected were there if they were looking for normal behavior patterns.
I know this is true because I have done it and have used this new knowledge and information to reach that layer and dig the good stuff in both black dirt and the worst of the red clay stuff in sites all over this city.
Using the right tool for this really helps and I have one...so do you if you use one of these built on this platform.
You just need to understand what is happening and use it to your benefit.

I started here, dealt with the huge amount of problems then moved across the country to soil that is as close to perfect as you can get.
When we decided to move back I was depressed and horrified...how do you go back to hunting in some of the worst soil in the country after experiencing the best and still enjoy yourself?
I was positive I needed to get into a PI unit to even come close to having success here that I had gotten used to and I was looking into buying a TDI and starting to study up on how to use it in earnest.
Then I decided to use that F70 and see if it can be successful here too, somehow and in someway before making that purchase.
After hours of experimentation and using knowledge gained by hunting extreme iron infested sites back in Kansas I realized I had the perfect tool for the job all along.
All that was needed was some new knowledge, experience and a bit of outside the box thinking to unlock the key to it all.