High threshold in disc....something to this?

Topics related to Fisher metal detectors here, Off topic posts will be removed.
Fisher Videos
Post Reply
Posts: 82
Joined: Sat Dec 21, 2013 11:31 am
Location: Birmingham Alabama, USA
Been thanked: 13 times

High threshold in disc....something to this?

Post by digger27 » Thu Feb 16, 2017 3:45 pm

If you hunt with an F5 or an F70 you can do this, the F75 has no threshold control in disc.

For the last few hunts I have been experimenting with some new settings attempting to find high conductors in some very difficult sites and have been shockingly successful so I thought I would pop in here and tell you guys about it.
Don't know if it will work in your areas but here is the info...it might.

My soil here in Alabama is pretty mineralized, most of the time I get GB numbers from the low to mid 60's up to the high 70's...sometimes into the low 80's.
My mineralization bars on my F70 go up to 3 and they are usually maxed out.
On a borrowed Red Racer the numbers are into the mid 70's and higher and the circle is 3/4's to completely full most of the time.
Plus here in the city of Birmingham we have tons of extra iron here, naturally occurring in the soil, slag in all shapes and sizes mixed into the fill dirt by iron and steel factories that were the backbone industry that built this city from around the 1880's and then distributed all over the area as neighborhoods were built plus tiny bits, nails, bolts, nuts, flat iron and rusted objects of all shapes and sizes both shallow and deep due to many old homes and neighborhoods that have been knocked down in most of the areas I hunt.

I have figured out several setting combinations to combat all of this and learned a new language to enable me to get deeper in the bad stuff than most I have heard of and more importantly to ID targets that are heavily masked shallow and deeper because of all this iron.
So many of these public sites around here have been declared hunted out by hunters that have been scouring these areas for over 50 years and culled all the easy to find targets but I found they were not...there are many more but they are heavily masked and disguised and some a bit deeper which in this soil tends to skew normal signals into areas that are unrecognizable but actually are not if you learn some new behavior and indicators...as I have.

A few hunts ago I changed to these settings, I am a big tweaker and experimenter so these are probably my 1,342nd attempt at new settings trying to get ever better at getting depth and unmasking in this mess which we call devil dirt around here.
I have tried using high thresh before but at my usual low disc settings at 4 or under even for me the noise and chatter was too much.
I have also used maxed out disc before but I never thought to max out the thresh on those rare times I did.
These settings are unusually quiet, eerily quiet and that is something quite different for me.

On my F70...
Big DD coil
Sense at 97...could probably go higher or a bit lower but this is where I started
DE speed
Thresh maxed at +9
Disc maxed at 65
1 tone, monotone...others might work also, (1F adds that depth modulation back in), but I usually use monotone in disc
Notched in all the nickel area numbers because even though I am looking for high conductor coins with these settings I am still a gold hunter at my core so I just picked one possible gold area to notch back in not that I expect to find any but more for my piece of mind and to keep me sane.
The what if's can really bother me so notching in just one gold area helps.

Program 2 has all metal, SL speed, maxed out sense and thresh which I use to hunt in a lot around here but in this case is used as a check system if I find something in disc on program 1.

I move the coil slow, fast sweep speeds don't work so well here and you must be able to notice higher numbers that could be fleeting.
I look for regular conductivity high numbers, nothing is solid and stable but a range of numbers that only jump between about 5-6 with very few drops to iron, (checking signals in all metal), if they are relatively shallow up to 3".
The Fisher up-average everything here at 4-5" and definitely more due to all this iron so all good signals at those depths soar into the high 80's to low 90's...even nickels that are usually a common 31-33.
I use this up-averaging effect to my advantage and great success once I discovered the deeper masked targets all do this here and when hunting in better black low mineralized soil but at sites infested with extremely heavy iron.

First hunt using these high threshold settings in an area in a local park I have hit a million times because it is at an entrance I use all the time I got an obvious dig me signal on a dime that was at about 4" deep.
Some jumps down to iron but this was due to some big deep iron under the area plus a very rusted disc in the hole with this dime that I am assuming is one of our war era one cent coins which were made from steel during the war years.
Rarely do we find these war coins here in decent shape, the steel just rusts heavily if buried in the ground for decades and they are usually unrecognizable as coins except by the size and shape.
I still got enough good, positive indicators to dig this suspected high conductor hiding here and to my surprise it was not a modern clad dime but a much better silver version...and I was shocked at the time.



The next day hunt number two I went back to this park and found some modern clad hunting some of my favorite well hit areas but not much else and on the way home I hit a small lawn of a private home I hunted more time than I could count last year and found a lot of great things, old coins, a silver religious medal, an old pocket watch, but now there was no good signals left except iron on the last several visits so I thought I was done here.
I hunted it hard because there was so many good targets in this virgin site, gridded it, came at all areas from several directions using several coils and settings and even two other detectors...there was nothing left here for me to dig unless I wanted more iron in my collection...I thought.
This time I just made a quick pass through this lawn with the new settings and expected nothing but in about 3 seconds I was surprised with another obvious dig me for sure high numbered signal.
Some small iron nails in the hole with this thing but next to them came up this 2" long oval shaped object that I think is an old hair pin or a sash pin and marked sterling on the back.
Shocked again...I had no clue on how I could have missed this thing previously.


Third hunt the next day back at that park in another area that had been hunted hard by me and I assume many others over the years.
Found hardly anything here except a few modern coins and a bunch of junk and iron in the past but this time I picked up a coin that was at the very top of my bucket list because it is a target I should have found by now but never did.
This was not a dime as I had hoped to dig up one day but the much rarer quarter...we call these coins Barbers because that was the name of the head engraver at the mint that designed them in the 1800's.
This was not deep, maybe only 2-3", but I believe it was standing on edge in the ground and again there were other true iron targets in the vicinity.
I saw the silvery round target when I dug dirt out of the hole and I knew it was a silver quarter and it was still covered with dirt but I was thrilled that I dug a for sure silver Washington quarter...when I used my thumb to move the dirt off the top and saw the date and the type I was shocked again.


Three hunts, three silver targets that were masked heavily but I noticed anyway and noticed easily...still not sure the high thresh is doing all this but something is happening here.
There is a possibility I never got the coil over that third target but I can guarantee you that was not the case one the other two especially that piece of jewelry from that small lawn.

Yesterday one more hunt this time in curb strips, grass areas between the sidewalk and the street.
These strips run down the block and in front of a park and neighborhood that goes back to 1898 and where mansions were built starting in 1901.
This enclave was where the richest of the rich built homes and lived and I have a friend that lives right across the street from the entrance to this neighborhood which is still exclusive and high end.
He has lived in this house since the early 70's and he told me he has seen legions of hunters hitting these strips since he moved there.
These guys did a good job cherry picking the high tone easy stuff over the years, there are still plenty of low conductors but high conductors are few and far between except for cans and other garbage like pieces of old pipes and other trash.
I have managed to find a couple of high conductor targets they missed on previous hunts using a sniper coil but this time on this hunt using that big coil I got another, again heavily masked and again an older coin this time a 1918 wheat cent.
This one is dirty but not really worn with sharp details front and back so I am assuming dropped pretty early on in its life...and everyone missed it all these years.


So the jury is still out,is it the high thresh doing this making iffy signals better, is it luck or something else?
Is the much quieter environment and less chatter and jumping around than my usual settings helping me to notice these good signals better?
Still don't know, more hunts and data to collect but I think something interesting is happening here.
A few F5 and F70 hunters on some forums over here are curious so they said they are going to try them and if any of you guys over there want to try please do and I hope they work.
Please tell me in this thread if they do.

Birmingham Alabama...USA
F70, F2, Mojave, Compadre, Compass Judge2
"Reality continues to ruin my life!"
2017 Totals...Clad, 11 silver targets including a freaking 1898 Barber quarter and 2 V nickels...

Posts: 3629
Joined: Thu Sep 12, 2013 2:47 pm
Location: Cheshire
Has thanked: 173 times
Been thanked: 756 times

Re: High threshold in disc....something to this?

Post by Koala » Tue Feb 28, 2017 1:37 pm

Some nice finds.

Setting obviously working well for you.

Posts: 6439
Joined: Sun Nov 27, 2011 8:21 pm
Location: North Lincolnshire
Has thanked: 521 times
Been thanked: 984 times

Re: High threshold in disc....something to this?

Post by sweepstick47 » Tue Feb 28, 2017 4:09 pm

An interesting thread with much experimentation involved to get the better of the conditions you're experiencing. ::g It seems that being a confirmed 'tweeker' (not to be confused with 'twerker)! :E you are liable to come-up with the ideal settings for your favoured sites together with the all important good finds to show for the effort expended. Good Luck and keep 'tweeking 'n twiddling'
Regards ss47 ::g
Arado 130 - Garrett Groundhog - Tesoro Eldorado - Fisher 1265X - Goldmax Power Makro Racer. Homemade Harness!

User avatar
Rivers rat
Posts: 337
Joined: Sat Jul 27, 2013 6:33 pm
Location: London(UK)
Has thanked: 88 times
Been thanked: 47 times

Re: High threshold in disc....something to this?

Post by Rivers rat » Thu Mar 02, 2017 8:05 pm

if it is like on a Cibola it will boost the audio signal so yu will hear the faint signals louder......no more raw power really just more sensitive

Owner of a Foster PI one of the Enlightened few

Posts: 237
Joined: Tue Jun 12, 2012 6:59 pm
Location: Surrey
Has thanked: 8 times
Been thanked: 8 times

Re: High threshold in disc....something to this?

Post by chesters4 » Wed Apr 19, 2017 8:46 pm

I turn it slightly negative on my F5 the field i am in at the moment had a smithy on it and theres billions of iron flecks so rather than turning up the discrimination i make it less receptive to tiny signals ,running it normally it sounds like my F75 but without the decent targets to match!
You can do the same with the F75 in all metal but i havnt bothered to see if it crosses over to the discrimination side.
The audio pitch does which i found unnerving until i realised why the noise in discrimination mode had changed rl;
I dont think you will ever remove every non ferrouse thing from a field i spent a happy couple of hours with coins on their edges and just slightly off vertical and in some cases you only got a decent recognisably good signal on a certain sweep of 5 degrees to it or so approching the coin at a different angle could be mistaken for the general chattering you get on high sensitivity trying to winkle bits out from the iron
Gold especially in my case is down to me going back to check a very iffy signal thats usually small iron but it niggles me enough to check again
Unfortunatly going positive to far means you hear the horse fences louder ,theres lots of them here and no way to tune them out !

Post Reply

Return to “Fisher Forum”