Findmall.com
 
 






Minelab X-TERRA Forum


Welcome! Log In Register
avatar
Re: Help, I wonder if someone with a 50 or a 70 can do a test(ferrite required)
Posted by: McNickle
Date: June 16, 2006 06:02PM
I wonder if someone that has either a 50 or a 70,AND some ferrite to GB it to.....Then see if it will perform as yours does...
(Reading the Ferrite at -4 in All Metal....AND...Not seeing the ferrite in Disc. Patterns 1,2,or 3)..
Sounds silly I know....but just a thought...?

avatar
Re: Tom, my guess is a x-50 may do the same.
Posted by: Jackpine Savage
Date: June 16, 2006 06:26PM
Tony,

You could be right on the acceptance range difference. I have never adjusted a manual or preset detector to ferrite, only to the ground and don't know where ferrite "reads" on a detector.

Hopefully Monte, Mr. Bill or someone else with a little more technical background could help on that.

Tom

Tony, using a piece of hematite iron ore
Posted by: John(Tx)
Date: June 16, 2006 08:29PM
on my XT50, both the all metal and pattern one read the sample as a -9. I then notched out -6, -3 and +3, but accepted the -9 on pattern one and it still read the hematite as a -9. Pattern two will do the exact same thing as all metal when all targets are accepted. Maybe the hematite is different than your ferrite? Hope this helps. John

avatar
Thanks John. Seems yours works as expected.
Posted by: tony (Orlando, FL)
Date: June 16, 2006 08:35PM
I am going to look for something like a paper clip or similar that reads in the iron range and see if this scenario I am seeing is specific to ferrite only or other items in the iron range too.

I appreciate your help.

Tony

avatar
Just tried it
Posted by: tony (Orlando, FL)
Date: June 16, 2006 08:41PM
John,

A paper clip reads a -4 on the x-30 like the various ferrite samples I have does.

The x-30 CAN detect the clip in ALL METAL and DISC mode ALL METAL.

Whats is even more strange is this..... IF someone is thinking the ground balance is way out or something like that..... the all metal pinpoint mode DOES NOT respond to the ferrite at all either.

Tony, I used three (3) different pieces of ferrite and my X-Terra 70. ** LENGTHY **
Posted by: Monte
Date: June 16, 2006 10:09PM
and compared the ferrite balances and settings, and compared the ferrite Ground Balance in my area here in Western Oregon, and yesterday I made a 250 mile round trip (just got home this morning) to see what some Central Oregon ground conditions would do, using a "ferrite GB setting." (Oh, I also worked in a little old site hunting but naturally doing an evaluation to answer your problem was more important :D so I concentrated on it.)

I also used an X-Terra 50, but didn't have an X-Terra 30 handy. I am going to go to a Minelab Dealer friend's shop today or tomorrow to use his X-T 30 and confirm my suspicions, but here are some general comments about doing such a test, about factory pre-setting the GB, and reflections about my observations and suspicions.
*
*
A Few

One additional thought (short) regarding the Pattern motion and All Metal motion modes.
Posted by: Monte
Date: June 16, 2006 10:20PM
I really think the main issue is related to what the absolute LOWER-END rejection (discrimination) amount is with the different X-Terra models, but another thing that could be a cause is that the Ground Balance (regardless of how it is set) could have a slight + or - "off-set", so to speak, between the All Metal and any Pattern mode. Not highly likely, but possible.

Monte

avatar
Here is a pic of the three ferrite samples I use
Posted by: tony (Orlando, FL)
Date: June 17, 2006 06:05AM
Thanks Monte,

you put a lot of effort into the reply, I appreciate it.

Just for the record, I do have and use three pieces of ferrite all different shapes and sizes and all do it.

When some other detector responds to ferrite, in the motion disc mode, it is usually a broken or erratic response in my experience with not much detection depth. Rarely a solid clean hit.

On the x-30 its as clean as can be, never wavers and have good depth.

This is waving it side to side, to and fro etc etc.

In the pinpoint mode, none of my samples sound off in the least.

Whatever is happening is definately not causing a problem detecting with it. The unit is as stable and deep as one could want here in Florida. I can run max sens and find small things at max depth.

I just happened upon this characteristic as I was putting some ferrite back in the truck and decided to see what the X-30 thought of it.

Maybe I will take the ferrite to a local dealer when in the area and see how theirs responds, unless you get to test it first and hopefully see the same thing I am.




Monty...A little knowledge is just that.......MattR.UK.
Posted by: MattR
Date: June 20, 2006 06:11PM
Monty.......

There is an old saying, "A little knowledge is a dangerous thing".

Your well intended post is an example of such.

If you think that ground balance is simply represented by an arbitrary piece of ferrite, then brother you have some way to go along the technical road of detecting theory and practice.

I offer no offence by such an observation, but rather a timely reminder to all budding 'experts'.

Go back to your studies of all the associated practical physics involved in this complex science, and then reconsider your observations.

When you feel you have got that sorted, then study the various methods used in designing the ground reject circuitry in the detectors to which you are referring.

You deserve full marks for your efforts, but not for your dogma.

The equation of life is:- Theory AND practice = EXPERIENCE.

You can get one from books, the other takes a life times application to acquire.....MattR.UK.



Edited 2 time(s). Last edit at 06/20/2006 06:28PM by MattR.

Re: Monty.......MattR.UK.
Posted by: John LA
Date: June 20, 2006 08:18PM
I sure like reading both of you guys tech info. I didn't feel that Monty was recommending the use of a iron ferrite in GB. I'm sure Monty will give his own answer. I appreciate both of you guys posting.

avatar
Am I the only one with an X-30 and ferrite?
Posted by: tony (Orlando, FL)
Date: June 21, 2006 12:16PM
Remember, this was a question simply asked for comparison of another X-30 unit, not much more.

I am sure there are techy reasons for what appears to be happening but I would just like to know if other units do as mine does or is mine perhaps in need of being sent back in.

So far, a lot of good replies, just kinda surprised none confirmed what I see.

I figured one of the dealers could have knocked this test out in a few seconds, maybe no one has an x-30 available.

avatar
Kind of a long answer..... but here is what I think......
Posted by: Digger
Date: June 21, 2006 03:15PM
I don't think that using a piece of ferrite has anything to do with my theory of why you are getting the results you posted. I think it is simply a matter of zero discrimination versus accepting various notches. And, as I will explain later in this post, these results can be found throughout the accept / reject patterns.

I don't have a piece of ferrite. I did, however, find a piece of low-grade iron that read a consistent -4 in the all metal mode on my X-30. When I allowed all the notches to be accepted in the Pattern mode, I found that the iron also read a solid -4. No difference with the iron in either mode. I also checked the same piece of iron with my X-70, using the same parameters of rejection and acceptance. (I would have also made the test with my X-50, but it is at the shop.) Anyway, the X-70 read the iron at a -4 in all metal and a -4 in the Pattern mode. What do I make of this? I believe my X-Terra is doing exactly what I asked it to do. And, I believe yours is doing exactly what you asked it to do. We both asked them to detect items with a "reading" of -4 or "higher".

The all metal mode of all the X-Terra is providing "true zero" discrimination. In other words, it does not discriminate anything metal. The Pattern mode of the X-Terra allows us to reject targets that fall into the notches we program it to reject. And, accept targets that fall into the notches we program it to accept.

For the sake of discussion, I believe the piece of iron I used is truly a "-4". If it were lower, the wider range of notches on the X-70 would have registered it lower. Like a -6 or a -8. Since the X-30 only goes as "low" as -4, that is where it read in the all metal mode. Remember, the all metal has zero discrimination. And, since my X-70 will read "down to" -8, but read this as a -4, I believe it is a -4. When I set my notches to accept targets reading -4 on each detector, it read the iron at a -4 in the pattern mode as well. Along this line of thinking, if a piece of ferrite had the properties to be in a lower notch segment, I believe it would have registered it in all metal on both detectors. But, I also believe it would not have registered in the pattern mode with notch segment -4 being accepted. Why? Because it is "lower" than a -4. The all metal mode is zero discrimination and the pattern mode simply accepts targets that fall within a given notch segment. And, we set ours to accept targets falling into notch segment -4. In the case of the X-30, a -4 is as low of indication you will receive in either mode. Accepting notch segment -4 does not accept anything other than targets with properties belonging to those in that notch. Nothing lower and nothing higher.

Again, I realize this is not using the ferrite, as you asked. But if that piece of ferrite has the properties of anything lower than -4, it will read a -4 in all metal (due to that being as low as it goes). It will not read at all in a discrimination pattern with -4 accepted, because its properties are "lower" than -4.

I believe the theory of these results will be the same throughout the discrimination spectrum. Detectors will only detect what we allow them to detect. For example, I have a pulltab that reads a solid 24 on all of my X-Terras. I also have an IH cent that reads a 24 on the X-30, 24 on the X-50 and a solid 26 on the X-70. If I set notch 24 to reject that pulltab on the X-30, it also rejects the IH cent. When I set the notch of my X-50 to reject that pulltab at notch 24, it also rejects the IH cent. However, when I set the notch of my X-70 to reject the pulltab at 24, it still hits the IH at the 26. Simply because the notches are more refined on the X-70, and the target I am rejecting is a bit different that the target I want to accept. Enough of a difference that it can be separated by the two digit notch segments on the X-70. But not enough to be separated on either the X-30, with its 4 digit notch segments, or X-50 with its 3 digit notch segments.

Another post mentioned that the X-70 has more lower end adjustment than the X-50. Although this is true (as far as the number of notch segments used to cover the "iron range" for each model is concerned) the X-50 actually has the capability of "going lower" than the X-70. The X-50 can register targets with a reading of -9. Whereas the X-70 will register the lowest targets with a -8. And, as mentioned above, the X-30 "bottoms out" at -4. So, even though you can "fine tune" the X-70 to either accept or reject more defined notch segments, the X-50 should (theoretically) detect (-9) targets in a Pattern mode that neither the X-30 or the X-70 will detect.

Again, I don't have ferrite to do the test that you asked. However, I believe that if you test various items with all three units, you will find that the readings are close, but not the same. And that is due to the "width differences" in the notch segments. And, since the X-30 only goes to a -4, IF your ferrite sample is "lower" than that, it will do exactly as you described. At least that is how I see it. HH Randy

Randy



Edited 2 time(s). Last edit at 06/22/2006 12:09AM by Digger.

Excuse me, Matt, but I don't think you got the message.
Posted by: Monte
Date: June 21, 2006 03:53PM
You stated:

"There is an old saying, "A little knowledge is a dangerous thing"."... I agree, but I will say my 'knowledge' AND 'experience' from over forty years of very active, dedicated involvement in this great hobby is perhaps a little above that of the 'average' detectorist. The trick we have to achieve when replying to posts is to get an answer that might help the inquisitor without being too technical.

"Your well intended post is an example of such."... If you're suggesting that I don't have much working knowledge and experience, come pay me a visit some time and we can go hunting a teach each other a few things ... maybe. :)

"If you think that ground balance is simply represented by an arbitrary piece of ferrite, then brother you have some way to go along the technical road of detecting theory and practice."... Nowhere and in NO WAY did I say that GB is simply represented by a piece of ferrite. Quite the contrary. There are too many variables involved and I have never been a big fan of using a dinky piece of ferrite to establish a decent, functional GB.

As for the "..technical road of detecting theory and practice", I have been traveling down this road since March of 1965 and 'practicing' all along the way. Theory is only part of the equation. Book-theory doesn't always pan out in-the-field, and that's one of the things that makes it tough for a book-learned engineer who doesn';t detect to understand what dedicated end users get frustrated about.

"I offer no offence by such an observation, but rather a timely reminder to all budding 'experts'."... No serious offense taken, but I am not a "budding expert," just a very experienced detectorist with a grasp of the issues who wants to try and help others.

"Go back to your studies of all the associated practical physics involved in this complex science, and then reconsider your observations."... Show me where I stated anything I need to reconsider, if you would. I pointed out that field-established GB is seldom going to be similar to that achieved by using ferrite, and that three different manufacturer-used ferrite samples differed from each other.

"When you feel you have got that sorted, then study the various methods used in designing the ground reject circuitry in the detectors to which you are referring."... I am always 'studying' especially 'hands-on' and have since day 1.

"You deserve full marks for your efforts, but not for your dogma."... Dogma?

"The equation of life is:- Theory AND practice = EXPERIENCE."... And you're more "experienced" than me or many others who have put in the time and worked in the industry through the years?

"You can get one from books, the other takes a life times application to acquire."... Perhaps you haven't read enough of my posts through the years where I have stressed to others that they should always be striving to learn and master their equipment. Knowledge and skills need to be combined. As I have since I started detecting in March of 1965 with a home-built "metal/mineral locater," the #1 thing I want to do whenever I turn a detector on, (in a shop, in the house, outdoors, anywhere) is to either learn something new or refresh my memory of something I have learned in the past. The #2 thing I want to do is find something exciting, and to best accomplish and appreciate #11 is to work at #1, which I have been doing all along, and still do in my 42nd year in the hobby.

Maybe it's something in the translation or I didn't type with an accent or something, but I think you got it wrong.

Have a great day and Happy Hunting, if you get out.

Monte

avatar
Randy , Thanks, that makes sense, let me chew on that a while....N/T
Posted by: tony (Orlando, FL)
Date: June 21, 2006 03:58PM

(This message does not contain any text.)


avatar
Monte, you'll always be welcomed back on the MXT forums with open arms. :)N/T
Posted by: Rudy
Date: June 21, 2006 06:26PM

(This message does not contain any text.)



HH. Rudy in CA
Do or do not.
There is no try.
Yoda

Sorry, only registered users may post in this forum.

Click here to login