Hi, I realize air testing is not a sure way of measuring depth but does the air test typically give a deeper reading or a more shallow reading? I am asking because it is raining out and I am in the basement with Simplex and Deus 2. Silver half and silver quarter. Basement floor is clean. Simplex is totally quiet prior to test and Deus has a little EMI from something. I can only get 3 inches on each machine before the signal disappears. Is this normal? Thanks!

depends on target "corona", moisture, and mineralization of the soil, but my experience single frequency air-test will be deeper. Multi-frequency air test will be shallower.
PI I think is about even, but I've not done much testing in that regard.

That seems very shallow.

Air testing is deeper than soil detection by about 1 inch in my world.
I place the detector in a vise parrell to the ground and then move the coin away from the coil until I lose the signal, I don't place the coin on floor.
My f5 will reach 11 inches on a clad dime using this method but only about 10 inches in normal soil.

casull454 said:

That seems very shallow.

Click to expand...

I was able to get outside for a little bit and was able to squeeze 6-7 inches out of the Deus 2 on the half. I guess maybe it's my soil (NW Indiana).

Sounds like emi is bad there, d2 does pretty well on depth but like other mf machines they can be crippled by emi. You can use the xy screen and see emi effect.s. I often end up using single frequency mode in tough areas.

If you are in the basement of a house when you do the air test, take and switch to all metal and then check it out again as the ground can be trash or iron you can not see, this will make difference and limit you depth. Also if you have any thing like light on it can also affect the air test. Most air test should be done outdoors and make sure it is ground balanced to get max depth, I do air test just to see what the meter will say for the ID numbers on different items. Another think I was told as there is no finds in the air, so do the air test in actual hunting with the detector. If you bury coins and see what depth they are they will be less than actual what you will get in the field .
I love my Minelabs and a few other detectors like my Troy Shadow X5 as when I bury some coins just to see what depth was, which wasn't very good for the price we paid for them, so I talk to Troy on the phone and told me the actual in the ground target will read deeper. I found this out in a old area that been gone over many time with top of the line detectors and piked up the coins other left behind. Air test got about 4-5 inches, but in this area the coins I were a good 6-7 inches deep with many close to nails. This can because they were going too fast and the detector didn't have the time to see the target.
Just take it out to a place that has had some activity and take your time and learn your detector, you will get a lot of new thing, but when you know it well find some older places and you will see how deep some target are.
I feel the Deus 2 is a great detector even though I never used one, but we have a fellow up here in ND that goes over so old parks and playgrounds and has one and seems like he all ways seem to do well in those well worked area so we know he understand his Deus well and know how deep it will go and what listen for

Good luck and let us know what you find and how deep it goes.

Rick

rick78 said:

I was able to get outside for a little bit and was able to squeeze 6-7 inches out of the Deus 2 on the half. I guess maybe it's my soil (NW Indiana).

Click to expand...

You don't say which coil you are using. Silver half you should get around 10-12 inches with the 9"coil. For elliptical coil, that sounds about right (6-8 inches) based on my experience with the same sized 9x5 elliptical coil I've used on another machine.
If you are using a set ground balance and have it set way positive, that will reduce detection depth. I personally like a positive GB, but only by 1-2 points... Example; if your soil gives a response of 85, set your GB to 86-87.
The reason I recommend slightly positive instead of balanced, is that it will reduce target falsing by a lot, but won't affect depth by any significant amount. However, if you want to eek the most out of the detector, go balanced.

rick78 said:

Hi, I realize air testing is not a sure way of measuring depth but does the air test typically give a deeper reading or a more shallow reading? I am asking because it is raining out and I am in the basement with Simplex and Deus 2. Silver half and silver quarter. Basement floor is clean. Simplex is totally quiet prior to test and Deus has a little EMI from something. I can only get 3 inches on each machine before the signal disappears. Is this normal? Thanks!

Click to expand...

@rick78 - Hi.
I don’t know how you’re conducting your air test, nor do I know your metal detector settings.
Coil size, the search program used, and the resulting search frequencies are equally critical factors.
However, most manufacturers specify the procedure in their manuals for testing how the detector reacts to various metals, coins, jewelry, etc.
It makes a huge difference whether or not you have locked the automatic ground balance.
The device's various filter options, target response speed, and other settings also play a significant role.
One factor to disregard here is the so-called "halo effect," which primarily occurs with iron that has been buried for a long time—though not exclusively with iron.
The higher the quality of the alloy or metal, the less pronounced the halo; gold and silver, for instance, barely form a halo at all.
But if the halo effect were truly crucial for a detector's depth performance, it would be impossible to search freshly plowed fields.
But I digress.
The Deus II manual also describes how to go about such a test.
Incidentally, my VX3 detects targets at the same distance during an air test in multi-frequency mode as it does in single-frequency mode.
That is by no means everything there is to know about this topic, but I hope it helps you a bit.
Don't take it to heart—just get out there and search. Practice makes perfect.
Besides, aren't the two devices you're using waterproof, or at least splash-proof?

Best of Luck & Have Fun

Ism said:

You don't say which coil you are using. Silver half you should get around 10-12 inches with the 9"coil. For elliptical coil, that sounds about right (6-8 inches) based on my experience with the same sized 9x5 elliptical coil I've used on another machine.
If you are using a set ground balance and have it set way positive, that will reduce detection depth. I personally like a positive GB, but only by 1-2 points... Example; if your soil gives a response of 85, set your GB to 86-87.
The reason I recommend slightly positive instead of balanced, is that it will reduce target falsing by a lot, but won't affect depth by any significant amount. However, if you want to eek the most out of the detector, go balanced.

Click to expand...

I am using the 9" coil. I will test some more today. I do have EMI issue. I just thought Deus 2 would be deeper. My property was built in 1933. I have found some wheaties etc with the Deus 2 but it almost seems like I have sanitized the yard with a Bounty Hunter Tracker IV and a Simplex. I guess that's possible. Just need to research some old sites. I will look into your GB advise. Thanks!

Air test at about 6" away to get an idea on how a target responds and can use the id's as a reference. Actual depth on a machine varies quiet a bit in the field. EMI is the biggest killer especially on smf machines. Ground mineralization and moisture content also effect the depth sometimes for good and sometimes for bad. Coil shape and signal footprint ie large coils more effected by those factors than smaller coils. Eliptical coils have a narrow response field and tend to do well in higher mineralized grounds as the signal is concentrated in a narrower field.
Wet grounds here can run hot and make targets respond more stronger and in the case of iron and other targets that have broken down over the years have a halo that responds as well. This can in some cases mask targets or affect their response that are nearby even with fast machines or quick recovery speeds. I like hunting old iron infested grounds when it's dry out as I get a truer response to them and better judge on their size and depth.
When EMI is the trouble in an area I try to hunt that in off peak hours. More power drain on the power lines the stronger the emi field is. I was detecting on a 1700's permission that was near the end of a dead end road and I could tell when the houses would draw as it would scramble my xy screen forcing me to use single frequency. As the power was used less the emi would magically calm down. My guess it was their ac units cycling.

As for depth I have found silver dimes in the 10-12" on the D2 with 9" coil with weak but clean signals. My deepest machine is the Tejon with 10x12 widescan as it can hit a nickel close to 16" and strong signal on a dime at 12" in the field. Air tests on that are less impressive in my basement than what the outside is.