Using Negative Discrimination

[Lodge Scent]

I like to try different settings or combinations of settings to be able to squeeze a few more goodies from my worn-out sites. Any remaining nonferrous targets are either iron-masked, super deep or both. Yesterday I tried another approach. I ran with a negative Disc of -6.4. I had hunted with negative disc in the past and had good luck but didn’t know why it had helped. I used it on Sunday’s hunt and dug another dozen nonferrous targets. But this time I figured out why it hit those targets that I had missed all the other times I’ve been there. In the adjacent slot to this -6.4 negative disc program, I ran the exact same program except it had the fairly standard 6.8 disc.  After digging the second button it became obvious to me. When I went over the target with the standard Disc of 6.8, I got a very broken signal with a noticeable iron buzz. With the negative disc I did not get the iron buzz. In the past I had just passed over these targets thinking is was iron. Most of the targets were deep, probably near the edge of detection. There wasn’t any iron in the hole, but as the manual indicates, deep nonferrous at the edge of detection can sound like iron. This isn’t a new revelation, but it just never really sunk home for me until now.

Crap, I just noticed one difference in the programs, the Negative Disc program had “0” Offset in Full Tones, but the 6.8 Disc program had an Offset of 10. Ugh, it shouldn’t matter though I wouldn’t think. The Tone Bin volumes for both were set at “0” up to the VDI of 38. I’ll verify if the Offset made a difference that next time out.

Lodge

[midalake]

46 minutes ago, Lodge Scent said:

Yesterday I tried another approach. I ran with a negative Disc of -6.4. I had hunted with negative disc in the past and had good luck but didn’t know why it had helped.

I used -6.4 as a test program on fringe targets. I did not notice any extra depth. I had issues with MORE iron wrap around.

But we are no doubt hunting in different modes and environments. I was primarily in Beach and Beach sens. on a wet salt beach. 

I will run a new test once I update. 

[Sinclair]

5 hours ago, Lodge Scent said:

The Tone Bin volumes for both were set at “0” up to the VDI of 38.

That will be the main reason you've missed presumably small stuff. There will be a lot of trash in that range, but some good things hide in those lower numbers ☺️

[iron_buzz]

That's interesting, but not enough information yet.  What were the conditions like there... both ground mineralization and nails (and anything else that may be relevant, like hot rocks, etc)?  What were the other settings, and why did you notch out (zero volume) 0-38?

[iron_buzz]

5 hours ago, Sinclair said:

That will be the main reason you've missed presumably small stuff. There will be a lot of trash in that range, but some good things hide in those lower numbers ☺️

Sometimes I'm willing to risk that though, if it reduces the signal/noise ratio for me.

[Chase Goldman]

22 hours ago, Lodge Scent said:

 After digging the second button it became obvious to me. When I went over the target with the standard Disc of 6.8, I got a very broken signal with a noticeable iron buzz.

It would be helpful (to us) to know the VDI of this target, especially in relationship to the 0 - 38 VDI range you effectively notched out below.  Knowing the base program for both would also be helpful (Sensitive, Full Tones?) and whether any other settings (reactivity, etc.) differed from the base program defaults. 

Note that if you are running full negative disc then there is NO iron bin and therefore you will get NO iron buzz regardless of your iron volume setting for any target even if it does have a "ferrous" component (intermittent "ferrous" IDs).  What I don't know is if the horseshoe ferrous-non-ferrous display would read out the same regardless.  Also, note that if you are running disc at "0" or have set a notch at "00-00" then no targets that fall in the negative disc bin will be audible even with iron volume ON.  You can only hear targets in the negative disc area if you set disc less than 0 and then you will only audibly hear targets above that negative disc setting as ferrous.

I really no longer use the "disc" programs (normal, fast, sensitive, Deep HC, etc), favoring Relic instead which does not have disc, but Iron Amplitude Reject.  It gives more expressive audio, though not tone ID because it is basically pitch - so I get a fairly clean differentiation between ferrous and non-ferrous at depth.  I use the TID as a guide for making dig/non-dig decisions based on the typical IDs of the trash at the site (which means I am digging all non-ferrous and all non-100% iron).  When I DO run those disc programs, I typically DO run with disc in the 7 to 10 range because it helps mitigate down averaging.  If the target is iffy with mixed ferrous and non-ferrous components (regardless of program), I use the horseshoe Ferrous/Non-Ferrous display to get additional info, turn on the target (rotate 90 to 360 degrees), and interrogate it with other programs with different frequencies and tone setups, as necessary. 

22 hours ago, Lodge Scent said:

Crap, I just noticed one difference in the programs, the Negative Disc program had “0” Offset in Full Tones, but the 6.8 Disc program had an Offset of 10. Ugh, it shouldn’t matter though I wouldn’t think. The Tone Bin volumes for both were set at “0” up to the VDI of 38. I’ll verify if the Offset made a difference that next time out.

You are correct, offset shouldn't have an effect, it only determines the "dynamic range" of full tones for the non-ferrous targets.  0 being the traditional full tones (tones ranging from low and difficult to distinguish from ferrous to the highest full tone for the highest conductors), 10 basically giving you some separation from the lowest ferrous full tone to the ferrous grunt tone, and 40 making all non-ferrous have the highest tone pitch in full tones.  This fulltones offset is a new feature that I have not experimented with much and will be interested in what you find out and I may play with it some more as well.  

[Lodge Scent]

Thanks for the feedback everyone. Sorry for the delayed response, it's been that kind of week. What I noticed was that when using Disc, nonferrous targets at extreme depth had a ferrous buzz so I tended to ignore them. With no Disc, the non ferrous at extreme depth did not have the ferrous buzz. As a result they caught my attention and I dug them. I was running Sensitive Full Tones, Reactivity 0.5 to 1.5. This is a cellar hole site with a good amount of crusty iron. I have very mild soils. 

Looking at my tone bins, 0 to 29 had a volume of "0". The tone bin of 73 to 88 also had a volume of zero. I've used that unusual tone bin at similarly pounded sites with lots of old iron. It knocks out the falsing and lets masked high tones peep through and catch my attention. I've used that approach that to pull a couple of small silvers recently from sites that haven't given up a high conductor in years. I had also Notched out 0-40 by accident (left over from previous program). With these settings the mid conductors jump out. There is a danger of some high conductors getting dragged down into the "silent" tone bin, But once again, these are pounded sites and I am trying every angle possible to dig a few more goodies. I wonder if there is any difference in performance between Notching out 0 to 40 or creating a tone bin from 0 to 40 with the volume set at "0" ??  

Chase I have used Relic and Goldfield and do like them in moderately clean ground as they are really deep. But at my sites with lots of crusty square nails, the falsing is still annoying even with the IAR jacked to 5. 

Lodge

[Chase Goldman]

12 minutes ago, Lodge Scent said:

The tone bin of 73 to 88 also had a volume of zero.

Thanks for the additional information, Lodge.  FWIW - That bin at zero would knock out a lot of the flat and two-piece buttons we recover at our Colonial sites that fall in the 73 - 78 range.   A lot of aluminum there too, though.  No easy day.

[Lodge Scent]

21 hours ago, Chase Goldman said:

Thanks for the additional information, Lodge.  FWIW - That bin at zero would knock out a lot of the flat and two-piece buttons we recover at our Colonial sites that fall in the 73 - 78 range.   A lot of aluminum there too, though.  No easy day.

Agreed. I've definitely pulled a LOT of buttons in that range as well as English coppers (usually counterfeits). For this type of hunting I am willing to sacrifice that VDI zone to just eliminate the iron falsing. I've tried a similar approach in Multi Tones by assigning  a low tone to those VDIs. But using Full Tones and setting that particular bin volume to zero seems to work better.