X-70 Blanking.....

[Digger]

For the past 6 months, I have been coin hunting with my X-50 in the all metal mode, and deciphering targets by their tone. I like to do that at many of the sites I hunt, which are old picnic grounds, fair grounds and race tracks. All of these sites are just farm fields today, so knowing where the buildings and grandstands set 100 years ago is difficult, to say the least. I have been able to locate these spots by running in all metal and listening for a concentration of ferrous targets. (nails).

Today I went out with the X-70 again. But today, instead of running in all-metal and deciphering the tones for nails etc, I decided to run in Pattern 1, rejecting only the ferrous targets. In addition, I set the threshold level at 4, just barely audible to my ears. What I found it that it is much more enjoyable to hunt with a slight audible threshold and allow "target blanking" on rejected targets. When hunting in all metal, I had to listen for the low tones and let my ears and brain separate the trash from the treasure. Those of you who hunt this way know how tiring it can be. With a slight threshold in the background, I can run in any notched discrimination Pattern, and when the coil passes over a rejected target, the threshold nulls out.

So, with the X-70, my days of all-metal hunting are over! I prefer to listen to a very faint threshold tone that goes away when I sweep over trash as opposed to hearing all of it and sorting it out as I go. I can still listen for the nails (target blanking) so I know when I am getting near an area that had a building or the grandstands. With the X-70, I can concentrate on only listening for those higher tones. For you folks hunting in all-metal, I encourage you to try this. It is a Great feature! HH Randy

 

[Neil]

Ill have a X70 in a couple of weeks and see how it stacks up against my beloved Sov

HH
Neil

 

[Digger]

The Sovereign is an excellent detector. But, I have a feeling that you will be very impressed with the X-Terra. It has a lot to offer. Weight, balance, reset times, sweep speed..... the list gets longer every day. HH Randy

 

[Jackpine Savage]

I also appreciate the ability of the X-T 70 to be set up to a users personal preferences. Being more of a fan of silent search detectors I have mine usually setup with threshold at 3(basically inaubile but it is there) and pattern 1 with -2 and sometimes -4 depending on the amount of iron, notched in and +48 notched out. Works for me!

Tom

 

[John(Tx)]

n/t

 

[John(Tx)]

n/t

 

[Larry--IndianaHVAC]

Randy,
I know exactly what you mean and I've been using the pattern 1 on the 70 also. I never realized how mentally taxing that it could be hunting in all metal for hours at a time. After a full day of hunting in all metal, it became mentally exhausting. I first noticed this when hunting with the Explorer in iron mask -14, just too much junk to listen to. The xterra line has certainly been a blessing from Minelab and they have created 3 winners for sure. Good post.

 

[Monte]

have the 48 rejected. The X-Terra 70 has many more notch segments than the X-T 30 or even the X-T 50 and there is more separation in the whole range of segments.

A 25

 

[Mike Hillis]

n/t

 

[Monte]

the last week or so. For so many years you would seldom, if ever, hear a term "wrap" used. If you were to view a sine wave and assign a breakdown to the upper-half of a whole wave that related to what targets we are looking for, you would see that there is a lot of 'range' below the point where yo go from iron nails to foil. Iron targets we find are man-made and, as such, they have not only the expected ferro-magnetic properties but also some conductive properties due to their shape and size, etc.

The "wrap" reference is really something that is difficult to explain, and actually hard to believe because it isn't really a case where the high-conductive coins "wrap around to iron" or where iron "wraps around" to the higher range.

Often a particular make or model will have some difficulty if the Ground Balance is not set properly for a particular mode. Some models have an adjustable GB in All Metal and a fixed (preset) GB in the Disc. mode. Some have a manual GB that is tied to both nodes, but there is an off-set of sorts between the two modes. By that I mean that while the GB might be "right on the mark" for the All Metal mode, it could be slightly positive or slightly negative for the Discriminate mode.

With the X-Terra 70 we are able to see that what we are dealing with is not just a "wrapping" of a target signal due to the GB setting, but simple a phenomena of the challenges encountered with motion discriminate circuitry in dealing with both ground signals and target signals. period.

With the X-T 70, you can use Track or Auto or Manual GB in BOTH the motion discriminate Coin & Treasure mode and note that the GB reading or setting is identical to that required for the conventional All Metal Prospecting mode. So, that takes the GB factor out of the picture. Yet, with some targets naturally located, or planted such as the penny I used the other day, I get a -8 reading in the no-rejection All Metal motion mode, with the appropriate audio low tone, yet in the Prospecting mode I get a very pronounced positive target hit. Even with "Iron Mask" in Prospecting mode I get a good hit.

The term "wrap" is a more modern-use term. If we call it the way it really is, it's just a fact of life. The metal detector can readily 'detect' metal. But when we ask various motion-based filter circuitry's to try and make any sense of the signal (or composite ground signal and target signal), we are asking too much of some of them if the conditions are really bad.

As for the 3 kHz frequency coil, so far I haven't experienced a natural lost/found situation or a fresh bury test situation where the 3 kHz coil handles the 'wrapping' issue better than the stock 7.5 kHz or higher 18.75 kHz coils. In the world of "Book Theory" it maybe should, but as yet I haven't seen it.

Sorry to ramble.

Monte

 

[Mike Hillis]

Sine wave above the center line you have non ferrous. Below the centerline you have ferrous. Not that ferrous & non ferrous have a touch point at start and another touch point at end.

You have large rusty ferrous crossing the line over into the high non-ferrous range at the ending touch point. Moving backward.

In mineralized ground using higher frequencies you have high conductive non-ferrous targets rising further up the id scale. If the id scale isn't large enough at the top end, then it crosses the line over into the ferrous range. The higher the frequency the more pronounced the effect. This crosses over at the ending touch point. Moving forward.

The worse the ground, the more pronounced the effect requiring lower frequencies to effect the change until you reach a freq that minimizes the effect. In these cases, a lower freq like the 3 kHz will excel and cancel any high conductive move into the ferrous range.

I'm taking this Monday off, so I'll get to do all the testing I haven't had time to do yet. While I'm out, I'll go to my best quarter wrapping sites with both the MF and HF coils and see if I can duplicate my past experience with the Xterra 70.

 

[Monte]

via E-mail.

I, too, am going to be working more with all three coils because I WANT to find some enhanced performance by the 3 kHz coil, especially in my nasty ground. W/O ground (air test) I haven;t seen any 'edge' to it over the 7.5 kHz 'M' coil, but in-the-dirt evaluations is where it needs to be done.

Later! Happy Hunting!

Monte
MonteVB@comcast.net