Myers Depot Metal Detectors

Using Notch instead of Disc?

pine3874

pine3874

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Duluth, GA
Everyone says that the more disc one uses the performance of the detector decreases. So when I read in one of the posts that notch only affects the audio response, I asked myself the question, why does everyone use disc instead of just using notch? By setting my disc at 0 and using notch to eliminate any targets I don't want to hear including iron, it would be like hunting in all metal, not loosing any depth and helping with the unmasking of targets. Has anyone tried this and if so, what were the results? It could be that I am completely wrong about this and if this is the case, please set me straight. Thanks
 
I think that is an interesting question. I have not heard that discussion before. I will be watching this thread for the responses from persons more knowledgeable than I am. Thanks.
 
They are one in the same.. Notching refers to just discriminating certain thing.. like bottle caps and pull tabs.. rather than just iron.. So if the machine has 5different icons going across the screen, you cold have 2 of them discriminated off and it would be like notches...
 
I'm not a firm believer in the "more discrimination = less depth" concept. Try this. Test the depth of your detector on a dime in all metal and then turn the discrimination all the way up and test it. Pretty much the same depth with the exception of a few detectors. I do understand the thought process behind less discrimination is better, but I don't believe depth is the reason.

I do believe higher discrimination CAN have a negative effect on depth from masking and slowing the processing down due to more filtering. Both dependent more on a detectors ability and the users knowledge of proper use. Slowing down will improve the bad side of both. Notch works on the audio portion of the circuity in most cases and really is just not producing a tone for the targets in the notched range(s) and so does not slow down the target in the filtering circuits as discrimination can. It can still cause masking issues.
 
Disc DOES effect depth on my Sovereign!

I have done this many times and with the same result. When I hunt the beach I ALWAYS hunt in "all metal/pinpoint" mode on my old Sovereign Elite. When I get a target in "all metal, I switch to "disc" mode to ID the target. A lot of times the target will disappear and I will be forced to go back to all metal and pinpoint the target and dig it. After I remove 8 to 10 inches of sand, I can usually get an ID in "disc" mode then. A fair percentage of the time it will be either a zincoln or a dime at a depth up to 16 inches!! Now granted, I run sensitivity all the way hot, as high as I can. Any one who wants to dispute the depth, can keep it to themselves here, several hunting buddies have seen this happen.

The point I am making is that my Sovereign will see deep targets in all metal that it won't see in "disc"...
 
I know what you're saying Robby but try the same thing in the air. It is the minerals in the sand masking the faint signal. That is what I meant by it being dependent on the machine and settings. If the detector is in clean ground, or able to be adjusted to properly cancel the ground, then the depth will be pretty much the same. So while you can say it is the discrimination causing you to loose depth, the true reason in the ground. It is due to the discrimination that allows the ground to cause a loss in depth.

In the end the results are you can lose depth when using discrimination so it is just nit picking, but the key word in that statement is CAN. You may not. Kind of like the statement that "Guns kill people"
 
Detector said:
I know what you're saying Robby but try the same thing in the air. It is the minerals in the sand masking the faint signal. That is what I meant by it being dependent on the machine and settings. If the detector is in clean ground, or able to be adjusted to properly cancel the ground, then the depth will be pretty much the same. So while you can say it is the discrimination causing you to loose depth, the true reason in the ground. It is due to the discrimination that allows the ground to cause a loss in depth.

In the end the results are you can lose depth when using discrimination so it is just nit picking, but the key word in that statement is CAN. You may not.
Click to expand...

That's what I just said... As far as Air tests go, I believe Air tests are a joke. I don't hunt in the air and targets don't get masked from a Minelab.
 
robby4570 said:
I have done this many times and with the same result. When I hunt the beach I ALWAYS hunt in "all metal/pinpoint" mode on my old Sovereign Elite. When I get a target in "all metal, I switch to "disc" mode to ID the target. A lot of times the target will disappear and I will be forced to go back to all metal and pinpoint the target and dig it. After I remove 8 to 10 inches of sand, I can usually get an ID in "disc" mode then. A fair percentage of the time it will be either a zincoln or a dime at a depth up to 16 inches!! Now granted, I run sensitivity all the way hot, as high as I can. Any one who wants to dispute the depth, can keep it to themselves here, several hunting buddies have seen this happen.

The point I am making is that my Sovereign will see deep targets in all metal that it won't see in "disc"...
Click to expand...

Detector said:
I know what you're saying Robby but try the same thing in the air. It is the minerals in the sand masking the faint signal. That is what I meant by it being dependent on the machine and settings. If the detector is in clean ground, or able to be adjusted to properly cancel the ground, then the depth will be pretty much the same. So while you can say it is the discrimination causing you to loose depth, the true reason in the ground. It is due to the discrimination that allows the ground to cause a loss in depth.

In the end the results are you can lose depth when using discrimination so it is just nit picking, but the key word in that statement is CAN. You may not. Kind of like the statement that "Guns kill people"
Click to expand...


Somehow I omitted the fact that WHEN I AM IN "disc" mode,
I have disc and notch knobs at full counter clockwise or minimal disc and notch settings​
 
I don't hunt in the sand so should I think that is a joke? There are people out there that hunt in very low mineralized ground that would not see this loss. Just because you don't doesn't mean no one does.

Point is, using the statement "discrimination causes a loss in depth" is like saying guns kill people. Truth is minerals in the ground CAN cause a loss in depth when using discrimination. It also may not.

As far as air tests. Show me just one single video of someone getting more depth in the ground than in an air test and I'll show you thousands of videos showing people getting no more depth in the ground than in the air. I believe air test are useful for many things. But hey, that's my opinion.
 
Detector said:
I don't hunt in the sand so should I think that is a joke? There are people out there that hunt in very low mineralized ground that would not see this loss. Just because you don't doesn't mean no one does.

Point is, using the statement "discrimination causes a loss in depth" is like saying guns kill people. Truth is minerals in the ground CAN cause a loss in depth when using discrimination. It also may not.
Click to expand...

It works the same in the dirt here as well. Some targets will be there in all metal and not in disc, threshold will NOT be nulling, so, no Iron to mask the target. I s'pect your next argument will be that you don't hunt in MY dirt? The bottom line is that you WILL NOT get the same depth in disc as you will in all metal...
 
LOL. No my argument is a simple one. A one of logic.

If you get the same depth with or without discrimination in the air but in the ground it is different, wouldn't logic dictate the ground in causing discrimination to cause a loss in depth? Again I say it is just nit picking but you might as well get it right.

he bottom line is that you WILL NOT get the same depth in disc as you will in all metal...
Click to expand...

Not correct, but I will meet you half way and say it CAN cause you to lose depth which is more correct.
 
Detector said:
LOL. No my argument is a simple one. A one of logic.

If you get the same depth with or without discrimination in the air but in the ground it is different, wouldn't logic dictate the ground in causing discrimination to cause a loss in depth? Again I say it is just nit picking but you might as well get it right.
Click to expand...

So you're ASSUMING that the depth is the same in an AIR test?
 
I would really appreciate it if everyone would bring my thread back to the question I posted!! Really not a thread about disc and depth, but rather, is there any advantage in using notch over disc.

My question is: If I use Notch to discriminate out iron instead of using Disc, will it make any difference. And of course to do this, one must have a machine where it is possible to set disc at 0 and use the notch feature to get rid of the iron.

Thanks
 
Um.. he said, I get a target in all metal then I switch to ID and it goes away.. The signal was too weak for the electronics to ID so it shows nothing.. Not going deeper in AM just letting YOU hear the fact it sees something regardless of the fact that the machine does not have enough info to ID it..
 
pine3874 said:
I would really appreciate it if everyone would bring my thread back to the question I posted!! Really not a thread a thread about disc and depth, but rather is there any advantage in using notch over disc.

My question is: If I use Notch to discriminate out iron instead of using Disc, will it make any difference. And of course to this, one must have a machine where it is possible to set disc at 0 and use the notch feature to get rid of the iron.

Thanks
Click to expand...

On the AT PRO, you can only DISC up to 40 which is typically iron.
You can only NOTCH from 40 and up, so it is not possible to choose either notch or disc.
Having said that, I usually leave some iron in there (only disc up to 20) so I can hear where there are some targets.
If it is too trashy (iron) then I will turn it up closer to 40.

BTW, I found the other guys arguments about depth and air rather interesting-hopefully they will take it to another thread:D
 
Sorry pine. To try and answer your question the difference between discrimination and notch is as I said in the circuit. Discrimination uses filtering which can slow a processor down where as notching is only telling the detector not to produce an audio tone for the notched target(s). The results is using notching you stand a lesser chance of also losing depth due to masking. The down side is most notching is limited. The Deus has the ability to setup 3 different notches which is nice.

The AT Pro allows you to notch out 12 target ID segments in the conductive range, and discriminate 40 in the ferrous rage. For example you can notch out the pull tab area, Iron area and still accept the coin and gold ranges with no discrimination. This means in the event you have really heavily mineral ground, where using discrimination CAN cause a loss in depth, you can notch out what you don't want to come over the audio. Those notched numbers will still produce a VDI number, just no audio.

I like to put my videos where my mouth is. Here ya go!

 
First of all , I believe that notching is a form of discrimination. Now I don't know that I have the answer, but my experience with several machines tells me it's more about processing and swing speed. On my AT Pro, If I used any discrimination, it was primarily in the iron range and then for anything higher, I might notch out some areas. What I learned is that the more I notched out, the slower I had to swing because it seems it processed the information. Depth never really seemed to be effected. However, I just learned to process the information myself and run it wide open because it was faster. On my T2, I can't notch, only discriminate. I found that even with max discrimination, I could swing relatively fast with reliable results. For cherry picking, I felt more confident with the T2 in max discrimination than using the AT Pro with a lot of disc and notching. I attribute this to the T2 having a faster processor than the AT Pro.

Now on the FBS machines, like my new to me Etrac, they pretty much exclusively use notching. You can technically discriminate in the old sense of turning the dial up, but most run some form of discrimination pattern. They say discriminate, but it's done by "notching" in or out very specific areas that are known readings for coins, jewelry, bottle caps, etc. Since the disc patterns can be fairly extensive, there in lies part of the rationale for the slow swing speed required by FBS machines. I don't hear people arguing that the Etrac loses depth when using a pattern and I argue that any pattern besides a solid black out from left to right and top to bottom, is a form of notching.

Sorry for the length of this post, but the my answer to your question is that it depends on your machine. For me the AT pro processor isn't fast enough to handle alot of notching for it to be as reliable without it, a little notching yes. I love the AT Pro, but I almost extensively hunt wide open with it these days, because even though I can swing it slower, it just doesn't feel like the same machine to me. On the minelab, it uses notching almost extensively and the major impact I see is swing speed to allow the processor time to deal with it, and the results are generally very good for those that can handle this style of machine and swing speed.

Dave
 
I always thought of it as Discriminating out

and

Notching In

So if I disc the bottom 3 notches of the range out, and I want the third one included, I notch it back in
 
pine3874 said:
Everyone says that the more disc one uses the performance of the detector decreases. So when I read in one of the posts that notch only affects the audio response, I asked myself the question, why does everyone use disc instead of just using notch? By setting my disc at 0 and using notch to eliminate any targets I don't want to hear including iron, it would be like hunting in all metal, not loosing any depth and helping with the unmasking of targets. Has anyone tried this and if so, what were the results? It could be that I am completely wrong about this and if this is the case, please set me straight. Thanks
Click to expand...

Discrimination only affects the audio, that is, wether to beep on a target or not. It has no effect on the pre-amp gain, or the audio amp per se, except possibly in the area near the edge of discrimination.

Having said that, the effect will be largely determined by the detector design.

In a detector were the discrimination happens in the analog domain (analog filtering), you can lose depth, particularly for targets that produce signals near the edge of discrimination. This is because the analog filter characteristics near the edge are gradual and so there is no abrupt discriminate/no discriminate transition.

In other designs, the discrimination is done digitally, after the target ID number has been computed, then it is simply a matter for the microprocessor to determine if the TID is above or below the discrimination value and beep or keep quiet. In these types of designs, there should be no appreciable loss of depth.

Notch discrimination is done strictly in the digital domain for cost/performance reasons and should not cost any depth.
 
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