Axiom Detection Modes Explained

[Steve Herschbach]

The video below goes over it pretty well. However, I think the mode names confuse things a bit, so want to go into more detail here. Before I start however, if you have not read it already, please read my post about the Axiom sensitivity control. Understanding that control and not having it set too high is critical to everything else.

The Axiom detection modes are:

Fine Mode

Normal Mode

Large Mode

Salt Mode

Now, to look at that it implies you chose the mode according to the desired target size. Fine for tiny, Normal for medium targets, and Large for, well, large targets! And that is kinda sorta true…. but not really. 

The modes are basically pulse delay presets. A type of PI preprocessing sensitivity mode, unlike the sensitivity control itself, which is processing the signal after the fact. Due to digital processing it’s more complicated than a simple pulse delay control, but that’s the best analogy to go with for you techies out there.

Fine Mode has the shortest pulse delay, and so is the most sensitive across the board to all targets. This means the smallest targets in particular, but it also means ground and hot rocks.

Normal Mode is less sensitive to the smallest targets, but it is also less responsive to hot ground and hot rocks.

Large is less sensitive still, with good sensitivity on larger targets, but less so on the smaller targets. Some small stuff won’t be detected at all. But the worst ground will become invisible, and some of the more troublesome hot rocks.

Salt is specifically set to ignore the signal produced by conductive salt environments. Salt water is conductive, very low conductivity to be sure, but the same as very small gold nuggets, single post ear rings, and thin gold chains. You want this setting for wet salt beaches, but it will also tune out some tiny gold or other desired items. This is physics at work and can’t be avoided (read this link).

The mode names imply that the focus is on target size, but that is not what you normally will use to determine what mode to employ. It’s more about the ground conditions. Think about this instead:

Fine Mode = Normal Ground Conditions. I would have named it Normal Ground Mode, as in the normal mode you use for normal ground. The default mode for most uses, with best overall sensitivity to all targets, large and small.

Normal Mode = Difficult Ground Conditions. I would have named it Difficult. Let’s you are having problems ground balancing or with hot rocks in Fine Mode, and have done you best to use sensitivity, speed, and coils as a solution. Lower the sensitivity a bit. Use the ground balance window. If using a mono, try a DD. If none of this is working, go to the Normal Mode, or as I think of it, the Difficult Ground Setting. At this point you may be able to go back to a mono coil, or increase your sensitivity, etc.

Large Mode = Severe Ground Conditions. Yup, I would have named it Severe Ground Mode. What if Normal (Difficult) still is not working? Ground signals from hot spots, maybe in a fire burn area, or clay deposits. Perhaps really bad hot rocks. Large Mode is for the worst ground and hot rock conditions. Yes, you will lose some target sensitivity, but if everything sounds like a targets, that’s no good. So get rid of the false signals to make the real targets stand out better. This mode can be used to help alleviate some of the tiniest trash targets also, by desensitizing the Axiom to those targets. The main use however is for dealing with really bad ground. Again, be sure you have explored all the options in Normal Mode, like lowered sensitivity or DD coils, before going to Large Mode.

Salt Mode = …. Salt Mode! Yes, this is for use in salt water or on wet salt sand or soil. Wet desert salt conditions after a rain storm. It’s not all about the beach, but any salt conditions. As noted above (read that link!) tuning out salt also tuned out a class of the smallest conductive targets. Tiny aluminum, tiny gold, tiny lead… little stuff. This mode in all actuality is an alternative to the Large (Severe) Mode and should never be ignored as a setting even if salt is not involved. It may actually be the magic setting to make one particularly nasty hot rock just disappear.

So two pieces of advice. Think less about target size and more about the ground you are dealing with in choosing modes. And in general, use the most sensitive mode possible, no matter where you are. To aid in that, let’s treat the modes for what they are, a type of sensitivity control.  I am putting these numbers in reverse of order of choice since higher numbers normally mean more sensitivity. If this was a knob, turn it up or down.

4 = Fine Mode (normal ground). Your most sensitive mode, your first choice, and the default for that reason.

3 = Normal Mode (difficult ground). A little less sensitive than the above to difficult ground and hot rocks, and tiny targets.

2 = Large Mode (severe ground). For the worst ground, burn areas, clay domes and seams, and severe hot rocks. Can help with tiny trash, so a relic hunter looking for larger bullets when there is a lot of tiny lead or other stuff may prefer this mode.

1 = Salt Mode (salt ground). Usually for salt conditions, but also as an alternative to Large Mode on any really bad ground. Can eliminate tiny lead shot, small aluminum foil, and other troublesome trash targets.

Turn it up to 4 for most situations. Lower as needed. It’s that simple actually. Let the machine tell you when you need to go to a lower setting. For beach detecting, do not use Salt unless you really need it. Up in the dry beach, any one of the other settings may work, and should be used if possible. Always use the highest setting possible, dropping down a notch at a time until you find the mode that helps deal with whatever issue you are having, whether it’s bad ground, hot rocks, salt, or tiny trash.

I hope that helps rather than confuses. So Steve, you ask, why did they not name them the way you like? Well, the LCD was baked before I even saw it. One if the frustrations with this testing stuff is decisions being made before I even have a chance to comment. If I had been on board when the LCD was penciled out, the modes would be oriented to ground, and speed would have been reactivity. But I was not, so there you go.

[Steve Herschbach]

I want to add that I have run the Axiom around the world, and it handles ground extremely well. Fine Mode really is the Normal setting for almost all conditions. Salt is mandatory in salt water. As far as dry ground, it was only the very worst Tahoe beach conditions that foiled Fine Mode. Most people will never see ground like this, basically almost pure magnetite sand. The Axiom mono coils simply would not ground balance. DD coils were better, but the real solution was to go to Normal (difficult ground) mode. When set like this, the Axiom is the first PI that I have ever used that actually would balance perfectly and detect targets at good depth in almost pure magnetite. The ability of the Axiom to handle severe conditions is pretty astounding when you actually experience it like I have.

The Large (severe ground) mode will probably be the least used mode, reserved for the worst ground conditions possible, or to purposefully make the detector less sensitive to bird shot. It may come more into its own if any really large coils are ever released for the Axiom, as the more ground a coil sees, the more use a setting like this will have.

[HardPack]

Steve,

Question: In the Tahoe magnetite beach sands you were able to balance the 13x11 DD?  The 11x7 mono coil had problems balancing?

If this is the case I am starting to understand your leaning towards the Axiom 13x11DD; 11x7 mono package for the majority of western ground conditions. 
 

 

[Steve Herschbach]

All the coils balance if you use the correct settings. DD by its nature handles ground better than a mono, but the difference there is less pronounced with the Garrett DD coils. They are hotter than a normal DD. It’s all about hitting the wall with sensitivity, and you can alleviate that wall in various ways, but it all boils down to the same thing. A normal DD coil handles ground better precisely because they normally are less sensitive than the mono coils. Make the DD hotter, it is hotter on both on the target and the ground. There simply is no free lunch. To eliminate salt, you will lose some small gold targets. Set it to pick up those targets, you pick up the salt. People want some magic. Pick this up while not picking that up, but reality is some ground signals and some target signals overlap, and getting rid or one, gets rid of the other.

It would be interesting to have Detech make some standard DD coils for the Axiom. A narrower, more elongated response area than the Garrett Focused Core DD, and also less sensitive to smaller targets. But also milder response to bad ground.

[Deep Beeps]

On 12/11/2022 at 11:34 AM, Steve Herschbach said:

I want to add that I have run the Axiom around the world, and it handles ground extremely well. Fine Mode really is the Normal setting for almost all conditions. Salt is mandatory in salt water. As far as dry ground, it was only the very worst Tahoe beach conditions that foiled Fine Mode. Most people will never see ground like this, basically almost pure magnetite sand. The Axiom mono coils simply would not ground balance. DD coils were better, but the real solution was to go to Normal (difficult ground) mode. When set like this, the Axiom is the first PI that I have ever used that actually would balance perfectly and detect targets at good depth in almost pure magnetite. The ability of the Axiom to handle severe conditions is pretty astounding when you actually experience it like I have.

The Large (severe ground) mode will probably be the least used mode, reserved for the worst ground conditions possible, or to purposefully make the detector less sensitive to bird shot. It may come more into its own if any really large coils are ever released for the Axiom, as the more ground a coil sees, the more use a setting like this will have.

Thanks for all the info Steve... Your bringing us all up to speed and cutting down on that learning curve we are all anxiously awaiting with the Axiom. 

Really hoping this detector fills some gaps, especially when dealing with magnetite in the goldfields. What's your experience on running the Axiom though mixed cobble, with various sized, positive sounding, magnetite chunks mixed into it. Or even magnetite chunks mixed through shallow alluvium on bedrock. The real nasty stuff that sounds just like chunky deep nuggets sitting down there. The key here is not constantly magnetite, but variable bits and pieces, mixed through where your hunting.

Also, if you did have a chance to test this scenario out, how did the DD's iron check and the hot rock/double balance work out in your opinion? Do you think it can efficiently run in this situation and still be descriptive enough not to be digging every other chunk of magnetite.

Thanks again,

[Steve Herschbach]

The Axiom works as very well in scenarios like that, but I honestly have not worked in your specific situation, and so will say I just don’t know. The weird thing about a PI like the Axiom is you can be in what is normally really bad hot rocks and not even know it. All I can say is the Axiom handled the worst locations I could find in California, Nevada, and Australia.

The only time it struggled even a little was in using the ground balance window to tune out not one, but two really bad hot rocks. This was Australia, hot ground, plus ironstone and laterite hot rocks. I’m talking having the ground be one thing, this rock another, and this rock another yet. So three very different ground balance points at once. I was able to make the Axiom work, but it took playing with the ground and the two rocks all at once with the balance window, and finding a setting that averaged out the entire mess. I found gold in those situations, but the balance was not perfect, as in if I got the coil within an inch of the ironstone in particular, it would break through. But it was right there, an inch away.

A similar situation occurred in California burn areas, where the ground was one thing, some rocks another, and little pits full of ash another yet. Getting all three to settle down was challenging. Keep in mind I’m always pushing my sensitivity too high, which means I’m creating my own struggles! It’s always a battle trying to keep the machine as hot as possible while not having false signals be overwhelming, and I’m always pushing the edge.

The reality is the machine will easily tune out anything, but at what cost? You can make it as quiet as you want on almost anything, but will you want to? It’s always a trade, and I always worry if a machine is dead silent. That’s my clue to push it some more, until it’s noisy, then back it down to whatever seems reasonable. If I’m not digging a rock now and then I’m probably set too low.

I wish I could answer everything but the reality is the world is a varied place, and I can’t promise how the machine will handle places I’ve never been.