The Garrett AT Max And Aluminum Siding

[mh9162013]

2 hours ago, Monte said:

Most of the time, however, it takes a while to really get a handle on the sate environment, and then put in the time to thoroughly cover the area with the right detector, best coil, and working it slowly and methodically.  Only 2 Hours?  Not nearly enough time to do a good job of covering any 120 year old sire.

That's really good to hear, as it implies I'm not an idiot and that what I perceive as a challenge is due to the fact that it's actually hard to do.

As for boosting discrimination, I understand that it'll likely lead to missing out on good targets. But if I were to dig anything that rang up as a 70 or higher on my AT Max at that old house, I'd literally be digging a target every 45 seconds.

With respect to the larger targets, those were far larger than a coin, and only rang up as an 80 or so. I imagine a large cache of silver coins would ring up as a 90 or higher with an AT Max?

Yes, I was using the stock 8.5x11 coil yesterday with my AT Max. The more I hear people talk about that coil compared to the 5x8, the more I wonder why Garrett made that the stock coil! I want that coil for the reduced weight, if for no other reason. Then tack on the fact that it's better in trash, and it looks like the only reason not to get it is if I find an Equinox 600 for cheap.

I sometimes use Iron Audio, but not often. And I never actively hunt with it on. I only use it as a "tie breaker" when I have a target I'm debating whether to dig or not.

If I go back to that old house (with or without the 5x8 coil) with the primary goal of finding silver coins, what's the advantage of only setting my discrimination to 35? Is there a realistic chance that my AT Max could detect a silver coin and have the VDI ring it up in the 40s?

Thanks again for your advice here; it's much appreciated. ?

[GB_Amateur]

You've gotten a lot of good advice and there's nothing new I can really add.  The one thing that jumped out at me is that you had (only) 2 hours to detect that site.  But it sounds like you can go back, so that's good.  It takes me more than 2 hours just to figure out where I want to hunt and what settings (and coils) I want to use.

Sheet metal (both aluminum and iron -- aka 'tin') are really annoying.  Even if you can distinguish between them and good targets by sound, extent, etc. they tend to have such a zone of influence that leaving them in the ground leads me wondering what small goodie is hiding under or nearby that's getting completely overpowered.

With really short times to detect trashy sites, probably the best strategy includes moderate gain, high discrimination (above Zincolns and aluminum screwcaps), and ignoring the strongest signals.  But all of those compromises will leave good targets in the ground.

 

[EL NINO77]

With this type of detection, I would make a detection plan.
If you have the opportunity to return to this detection point ...
and from the beginning in the 1st round of detection, he focused on digging up reliable signals in a certain zone of VDI..that you are interested in ... in this case, you can afford not to dig targets whose signal you don't like ...

* If you are in doubt about what kind of target one is used to check the signal before digging .. pinpoint detector AT Max and try to raise the coil above the target .. to evaluate the size of the target..in combination VDI what target gives you ... what could you help avoid some big goals ..
 
 In the next 2 phases, if you return to this detection point, choose "another detection plan and extend the detection to VDI targets ... those that may also interest you ... and digging up any unwanted targets may bring you some more bonus ... in the form of a valuable coin or jewelry ....

Finally, up to 3 phases of detection of this place, you can afford to detect and dig targets with a certain VDI ... and remember that the pieces of aluminum waste can also mask some valuable targets that are stored lower..and if you have time to dig up unwanted objects ... so such detection will bring you some bonus.

 I highly recommend adapting to a given type of detection also a certain type of coil, a separation coil and then a deep coil ...... especially if you want to concentrate on digging the targets from the beginning, the VDI is right.

 

sometimes it pays to dig up some unwanted signals ... just so that you have an overview of what the terrain is .. but it doesn't have to be the rule ..

[kac]

On the AT Pro, Max and I believe even the Apex, old iron nails break at 33 so If your going to disc out try to keep no higher than that. My custom mode on my AT Pro I usually have iron disc at 33 but run more often in Zero until my brain hurts then I'll jump to custom.

On my Apex it has a straight up notch discrimination vs the AT series that have threshold disc up to 40 then go to notch.

On the Apex I have a custom mode that is basically like jewelry mode so 40-99 is on and only the very bottom notch on iron is kept on. This silences much of the bigger iron junk but if I nose off the targets I can still hear blips or minor grunts whithout being overwhelmed with audio. Any kind of discrimination you risk losing good targets. I suppose if there was a perfect machine that could filter out aluminum and keep the gold everyone would use it ?

I had a 9x12 concentric on my AT Pro for a while. Nice coil but not good in high trash as it didnt have enough target separation. They have a 6x9 concentric I never tried but again concentrics shine when there is a lot of iron. Flat iron is knocked down to the nickel range so it may make the task in that area your hunting that much tougher as bottle caps and flap pieces of sheet steel will end up in the aluminum range.

[JCR]

The 6.5X9 Concentric Garrett coil is excellent.

[mh9162013]

34 minutes ago, kac said:

Any kind of discrimination you risk losing good targets. I suppose if there was a perfect machine that could filter out aluminum and keep the gold everyone would use it

I know that using discrimination is a trade off, but I figured it was largely due to target masking. For example, if you discriminated out iron nails, but a silver coin is next to an iron nail, you risk hearing nothing when you pass over these two targets (assuming your detector doesn't have the recovery speed and separation ability to tell these 2 targets apart).

I also understand that depth can be an issue here too. If a silver coin is an 85 on the surface and an 82 two inches below the surface, it might be a jumpy 60-70  eight inches down (depending on soil conditions, of course). So if I've set my AT Max to only hear targets 80 and above, I'll never know I've swept my coil over this target.

But what other scenarios might "over discrimination" be a bad thing in the sense that you don't hear/see desired targets?

[mh9162013]

1 hour ago, EL NINO77 said:

If you are in doubt about what kind of target one is used to check the signal before digging .. pinpoint detector AT Max and try to raise the coil above the target .. to evaluate the size of the target..in combination VDI what target gives you ... what could you help avoid some big goals

I do that when I think I could be digging a large object. I'll also use my pinpointer on the surface to gauge the target's size. I've detecting enough with my F-Pulse to know what it sounds like when the target's just below the surface, but is larger than a coin. The catch is that many of these targets are within 2 inches of the surface. Sometimes it's just faster to quickly dig the target as opposed spend extra time to confirm its size before moving on.

As for your approach to hunting a site in phases, it makes a lot of sense. I just hunt all permissions with the assumption that I can never go back and that I need to focus on efficiency given my usually short hunting times.

[mh9162013]

1 hour ago, GB_Amateur said:

The one thing that jumped out at me is that you had (only) 2 hours to detect that site.  But it sounds like you can go back, so that's good.  It takes me more than 2 hours just to figure out where I want to hunt and what settings (and coils) I want to use.

The owner was friendly enough, so I think I can go back. But while hunting, I took the approach that I can't assume a second hunt. But I'll definitely try to hunt there again.

So 2 hours really isn't that much time, eh? Sounds like there's an echo in here ? Up until this thread, I honestly thought expert or experienced detectorists could dial in their machine to their soil and intended targets within 30 minutes or so (assuming they had the right equipment).

[GB_Amateur]

4 minutes ago, mh9162013 said:

I honestly thought expert or experienced detectorists could dial in their machine to their soil and intended targets within 30 minutes or so (assuming they had the right equipment).

I guess it's where you set the 'discriminator' on the 'expert' scale.  Soil and targets are part of the settings input.  So is trash distribution, trash type, depth of good finds, location of good finds, difficulty in digging due to ground type (clay vs. sand, depth of vegetation, etc.)....  But, yes, you've got to fit your hunt into the time available.  Now that you have permission to hunt more, I predict better results.