Should one discriminate out pulltabs? Bottle caps? Screw top caps?

[Pete in MI]

Here some information I have gathered to give you something to think about. Though these are taken from a special program for the Minelab Explorer the information is still useful for all detectors as the items (goodies) all fall in the same area on whatever readout you may have.

Here is picture 1:

[attachment 75936 Covered_1.jpg]

Looking at the area to just right of the number 1 - the black area represents 'pulltabs'. If you eliminate pulltabs what do you lose besides pulltabs? The red dots are the goodies you would lose in that area. These goodies include the following:

Gold ring (18 kt, 14 kt and 9 kt)
Men's Large Ring
Russian ring
3 Cent Nickel
Flying Eagle Cent
Gold coins (Two Dollar and a Half coins and the One Dollar Gold coins - talking real old gold coins not the newer Sacagewa or more recent gold dollars)
Five Cent Indian Head Fatty
Indian Head Cent Fatty
Five Cent Silver War Nickel
Five Cent Shield Nickel
Five Cent Jefferson Nickel
Five Cent Liberty Nickel

So if you eliminate 'pulltabs' look what you may have left behind for someone else.

Ok now to the next picture # 2:

[attachment 75937 Covered_2.jpg]

We now look at the blackened area to the left of the number 2. This is the 'bottle caps' (sometimes called 'crown caps') area. With bottle caps eliminated what are the goodies we may lose (the red dots again)?

Gold rings (18 kt and 14kt)
One Dollar Silver Eagle (which is just above the black area...but could be lost on lesser quality machines)

On to picture # 3:

[attachment 75938 Covered_3.jpg]

Here to the right of the number 3 is 'Screw caps'. Eliminate the screw caps and what goodies might we lose there?

Ten Dollar Gold piece
Five Dollar Gold piece
Three Cent Silver
Half Dime
Indian Head Penny
Russian Ring
Gold Rings (18 kt, 14 kt, 9 kt)
18K Diamond RIng

And here is pic #`4

[attachment 75939 Covered_4.jpg]

The little red dot in this area (where Iron is eliminated) represents the Steel Wheat Penny.

So I hope this gives you an idea what items (goodies) fall where in the darkened trash areas.

Only you can decide how much, if any discrimination to use.

 

[Mike from MI "Iron Brigade"]

block anything. I disc. by what reading I have, and where I am at. Like most I am sure I have not dug a goodie that I went over???
The best way not to miss these is to do what Steve from AZ does. Did it all!
Good visual Pete!

 

[Pete in MI]

that Mike (lowrider) - wonder how he is doing BTW - made?

I think either I missed something or there is a newer version out. It has Trace capabilities. That's where those red dots came from.

There are several zip files too of coins and rings - from the USA and other countries too.
I can post them somewhere if you want to download them for your emulator (can even post what I think is the newer emulator if is it newer). I have a web spot to put things like this.

 

[steve in so la]

g

 

[Mike from MI "Iron Brigade"]

n/t

 

[Mike Chgo area]

n/t

 

[warthog]

...I use very little discrimination...One day at the beach,I dug up 2 pulltabs in a row-the 3rd that read "Pulltab"came out as a very nice14Kt.ladies'ring-"tune out the tabs and screwtops,bye bye to the NICE stuff,too"......

 

[SNOWY]

Great post Pete !

What a valuable tool eh !!!

 

[Pete in MI]

It sure is Snowy. Thank you Sir.

 

[gvanvekoven]

Wow!!!! is this a problem with your machine or typical results for any machine? What is the use of having discriminate features if they mask out the good stuff in the same area?

Looks like discriminate would only be good if nothing else metal happens to be under the search coil. I was thinking about getting a Minelab machine - but now I wonder.

What is the deal here Bro?

 

[Bowie]

Thanks for that posting Pete in MI. I will say Im new but I did hunt years back a bit with my dad, using one of his machines. It didnt take me long and I was back in the saddle. He used Whites machines so I have started out with Whites but those Explorers sure have caught my attention and sevral other machines,lol.
I would like to reply if you dont mind. As I first started out I didnt know where to run my discrimination and to be honest I got tired of listening to the machine go off on targets in a nasty site I would be hunting,lol,frustrating especially for someone new. Then I recalled some hunts I made with my father and recalled some post I read on these forums and others.
To discriminate or not discriminate. In my opionion it depends on the individual,their hunt/site and time on hand. And its like steve in so az says,dig it all, your eyes are the best discriminators. But, we all dont have that time. And the great machines like your explorer gives us the advantage and tools to make our (present) hunt much more enjoyable and productive for the amount of time we have to spend on that particular hunt. Ive read the book by Robert Brockett, " Taking a Closer Look at Metal Detector Discrimination", read it several times,lol. Sure its a Whites book but its full of good info for detectorist.
I dont have a machine with notching capabilities but thats not to say I cant notch using my TID.
But in short, discrimination is a tool we can use to enhance our hunt if used properly.
I want to wish each and all of you a very Merry Christmas and remembering what Christmas is really about,
John

 

[Pete in MI]

You are right Bowie (and welcome to the forum). One thing about those old detectors with their discrimination as you turned the knob from off or low to higher it gradually eliminated each one. I have to think back but I think it was something like off - nails - bottle caps - pull tabs - screw tops. If you moved the dial to the highest position it didn't delete just that item say screw caps in this example but it deleted everything below it as well. So if your area you are detecting only had screw caps you had no choice but to either dig all signals or to discriminate out the rest of those...and lose a lot of goodies to boot.

Modern machine are much better with the notch discrimination. If pulltabs are a problem they can be notched out and you still have the others you will find and the goodies that fall in that area as well. No more losing things in those other areas.

Another thing about those machines...well I know Minelab so will talk about it. Say I have a problem with pull tabs and discriminate them out...I also have the capability - assuming I have a coin for each one of those goodies I can used to adjust the machine and not lose them even with pulltabs blocked out.

If I had a $20 gold piece for example I could put the Explorer II into learn mode and wave the coin under the coil and then be able to find any $20 gold pieces. Fat chance that I would have one of them to do that with.

I was like many who say what the Minelabs were doing...finding those old and deep coins. If you haven't checked out Minelabs go to their website and look up the info on FBS (full band spectrum). When I first read that it about knocked my socks off. No wonder why those Minelabs were finding things others were walking over and had gotte no signals with their machines.

I posted this just so people could see something and make them consider the use of their discriminating adjustments. Most when they first come into detecting think great I can get rid of pull tabs...and they do. But not realizing the gold and nickel and even silver they are missing or could be missing with those older machines...especially those old machines without a notching system of discrimination.

Hoping you and yours have a very Merry Christmas.

 

[Pete in MI]

You should read my post just above this one. It clarifies things (I hope) a bit better. The areas where goodies are lost is not specific to any make or model of a detector. All items have a certain conductivity to them and those areas like pull tabs are a broad band. In that range those goodies fall in that large band.

As I mentioned above Minelab (and maybe others) can Learn to open up small sections within that larger band (say pull tabs) so you don't lose those gold rings, coins, etc. But to be able to set the Minelab to block pull tabs but keep those inside areas open I would have to have one or more of each of those goodies to put in front of the coil and tell it to "block out the pull tabs but this one is ok so accept it when you see it". I don't know many people with those $!, $2.50, $5, $10 and $20 gold pieces let alone them let me use them long enough to scan into the computer of my Explorer II.

So if you do not have a detector that you can tell to accept a small area within the larger area, you will lose those items. And as mentioned with those old detectors if you turn the discrimination up you lose everything below that level so one loses lots more.

I hope I have made this a little clearer. The newer technology is the way to go and even then you have to know the limitations as well as the capabilities of the machine you have. That is why there is such a big learning curve to the Minelab....there is so much it can do and it takes time to learn it. By the same token with so much it can do...if you get the adjustments wrong you'll walk over things or detect things you didn't want. Takes time to know a machine but when you do...you will do better than someone with less experience - even if they have the newest machine on the market.

Hpefully that helps. I know Minelab now better than I did almost a year ago when I got it. I understand it more now than then. I haven't learned all there is to know but I have found items I know I would never have found with the other machines I had previously.

Getting to know your machine is like getting to know your car. Sure you know how to drive. You can drive another car but until you know that car - its potential, its limitations....you wouldn't put that old Chevy Chevette, the VW Rabbit or Lincoln Continental into a race with the big boys at NASCAR.

Let me know if this has helped clear things up a little. Have a Merry Christmas.

 

[John(H)]

Pete, one doesn't need an expensive detector to do what you are talking about! I started back when there was no discrimination whatsoever! And we basicly had to dig it all! BUT...................there was a select few who could tell whether it was a coin, iron nail, non-ferrous, etc. and this was basically done with an all metal BFO or All-metal TR! Now the notch system is good but .............it has its limitations. Many pull-tab and screw-cap readings are actually good targets, it is up to the operator to determine whether to dig or not! I feel that these newer machines give too much info and actually discourages one from digging all the questionable targets! it is too easy to look at the meter and just say " OH JUST ANOTHER PULLTAB" and just skip it! In the old days, all we had to go on was the the tone, and target strength and many recoveries was determined by THE GUT FEELING. Now don't get me wrong........................I do like the TID machines and do own at least 2 and many more I have used in the past. BUT.................I feel that they have a place and sometimes the best choice is NOT one of them. When I go hunting, I usually pack 3 detectors! One a has a TID meter, one has a notch system with duall tones, one is a VLF/TR! And these 3 will change depending on the site that I chose......................going to the beach I like the Garrett Seahunter, Whites 4900, Garrett ADS 7X. Going to an old homesite or Ghost Town...............Garrett ADS 7X, Compass 77B, Nautilus LF. Hunting for a specific target...............GMT Cobra. ....................................................NOW ONE MORE THING........................HOW TO MAKE A POORMAN's Minelab. I can take a decent VLF/TR or a motion machine with no TID meter. Now Benchtesting one can find all of the machines fall out points, you can mark these lightly with a pencil on the discrimination dial!....the nickel will fall out before the pulltab, etc..............So out in the field, I start out with low discrimination and make sure that my machine will pick up a U.S. nickel. Once I receive a signal, I will dial it up to see if the nickel fall out , then the pulltab. This way I can only hunt nickels and / or coins but still receive all the signals high and low! I determine what to dig, not the machine! Of course, this is time consuming and sometimes it is just easier to just dig the target! But when I'm limited on time and only want a specific target area this seems to work out best for me! ...........................NOW JUST 38 YEARS OF TH'"ing talking here........................................................GOD BLESS............................Joe

 

[Mike Chgo area]

n/t

 

[Pete in MI]

My very first and very basic machine was a Bounty Hunter...cost me $59 back then. (I bought 3 of them as that was the minimum number of detecotrs one could purchase to become a detector distributor for National Treasure Hunters League down in Mequite, TX. So bought those 3. Sold one, gave one to a co-worker who introduced me to metal detecting and I used the other one until I could afford the Garrett Master Hunter BFO which was top of the line at the time. I miss that machine. I was in England when I bought the Garrett. Detected there for a few years. I also sold a few detectors to others there. The others I sold were Whites detectors and the newer ones that came out with discrimination and were the TR detectors. This was back about 1973-76 (I was stationed with the U.S. Air Force in England for those 3 years.)

When I first got the BFO units, I was in the Upper Penninsula of Michigan. Was going to get out of the service and set up a detector sales company but the assignment to England was one I couldn't pass up. If I discriminate anything it is nails...unless I am looking to find the square nails that tells me I have found old buildings had been there.

Yep, Joe, I remember those days of old. I had pretty much remained a Garrett devotee for most of my detecting life. Had those Bounty Hunters in the beginning. The Master Hunter BFO, a few American S models, my first Whites was a Coinmaster...but was unsuitable to water detecting..and had others such as the GTX-1000 Ultra then the GTAx-1250 and a new ACE 250, a Fisher 1280-x, Tesoro Stingray water machines and now the Explorer II. Out of all those machines I miss the GTAx-1250 that I traded to a good friend (who seems to have distanced himself so we don't detect or do much of anything else any more). I have the ACE 250, a Tesoro Stingray for water detecting and the used Minelab.

I had a chance to buy a Master Hunter BFO from a guy down south who called me and said he had one. I felt bad that I could not afford to buy it. I had no job and he even offered to take payments. I just couldn't take it and not know if I could send him the money so I turned his offer done. Sure wish I hadn't done that. I miss those old days and that old BFO that served me well in England.
Thanks for the memories Joe. (I was also on the front pages of the Stars & Stripes newspaper in Europe with the detector, talking about the things I was finding and the fun I was having....:sad: didn't save a single copy of that newspaper for my family.

 

[king-ghidorah]

interesting thread and it has given me food for thought.

 

[Nick A]

This post is great Pete! Makes a lot of sense and it's good to see the screens with the targets highlighted on them. I've got a "but" though.

"If I had a $20 gold piece for example I could put the Explorer II into learn mode and wave the coin under the coil and then be able to find any $20 gold pieces."

I beg to differ, a bit. The learn mode scenario only works if the coin sought is under ideal conditions. If that $20 gold is near the maximum depth of detection, under a nail, mixed with trash, bent, chopped by a mower, on edge, or angled in the hole it will not give a perfect signal and may fall in a variety of places on the screen. So yes, it may find "a" $20 gold, but it still would not find every $20 gold.

I tried this with silver quarters. I love the things. I took my handful of silver quarters and waved them all under the searchcoil individually. Different angles, depths, all over to account for some of the variables. The discrimination grid was peppered with dots. Then I took it out to a super trashy site and let 'er rip. Did I get silver quarters? Sure did! Got a lot of clad ones too, and a handful of other stuff. So, in this case, it worked in cherry picking a super trashy site that I didn't have the patience or desire to dig all targets. I'm confident there are still silver quarters in that site though.

Air test (or air "learning") is not ground test. Skill of the operator of the machine and some luck have a lot more to do with it. My rule of thumb is if it's deep and bounces in some good areas, I'll dig it. In my neck of the woods, a pulltab at 4-5" is probably a pulltab. A pulltab at 7-8" is rarely a pulltab - maybe not a goodie, but a lot of times it is.

Two maxims to remember...
"The best discriminator is a shovel."
"It doesn't cost anything to dig."

 

[Pete in MI]

Didn't say that everything was carved in stone...still a lot of variables. It was more to give people something to think about and to illustrate (using the emulator - not the actual detector) to show what 'might be' missed.

You have a lot of valuable info to your post. Thanks. Helps people give even more thought to where to dig or not...when in doubt..dig

I am just using Iron Mask now instead of blocking out all the stuff I once did. I dig more trash but hey I just found another ring of unknown material.

HH and thanks for adding to the post.