Okay, maybe three.
1.. Was that an 'air test' depth measurement, or was that a measured depth of a coin located in the ground [size=small](and NOT a freshly planted coin)[/size] ?
2.. What was the sensitivity level you used?
3.. Out of curiosity, are you familiar with Tesoro detectors, or is the Mojave your first one?
To give a quick answer or comment: What coin were you using, and keep in mind that a lot of that Canadian coinage is made of what we refer to as 'junk metak' such as Nickel, Iron, Steel, etc.
On a freshly busied test target it might not provide typical detection depth performance.
I have a Mojave in my personal arsenal and I used the standard 7", a 6" and the donut 8" Concentric coil on it and opted to leave it as-is with the new 7" coil. It works fine, and I get sufficient functional depth.
Let's remember that ground mineral environments can change. Sometimes their might be nearby iron trashy that causes some masking and performance loss. And as good as this low-cost by useful detectors is concerned, it is a lower-priced, entry-level unit. It can work well for a lot of people and for a lot of applications, but for me it is only 1 of 5 Tesoro models in my arsenal. My Vaquero w/6" Concentric gets the best depth, if that is a comparison, followed by my Bandido II [size=small]micro[/size]MAX, very similar performance from my Silver Sabre [size=small]micro[/size]MAX, then the Mojave and it is a touch better than my original Bandido also w/6" coil.
If I am serious about wanting ... and needing ... increased detection depth, then I just grab one of my other detectors which, by design, provide me the increased depth of detection I might need. Those would be my Nokta FORS CoRe, FORS Relic or the new Impact.
To clarify 'depth' I should add that I have been metal detecting now for over 52 years, avidly, and Tesoro's are in my arsenal because these are all favorites that have proven their worth. Since '83 I have probably found more coins with a Tesoro model than all other brands combined. I have also found about twice the number of gold jewelry items with Tesoro's that will all other detector makes and models combined. Most coins and desirable jewelry are not located very deep on most places unless they has been some sort of outside action or disturbance to cause them to be located deeper for some reason. Surface to about 4" is where the bulk of the coinage comes from, and anything from over 4" to 6"/7" is what I consider to be a 'deep' coin target.
Can they be deeper and have I found coins deeper? Most certainly, Yes, but it is due to surface build-up from grass clippings and fallen, decayed leaves. Sometimes erosion, but that can also expose old coinage, too. At times old grassy areas have had sand or dirt added to build up or level a site, and that puts coins deeper. In some locations, if the ground gets well saturated with water and is heavily traveled on by vehicles, foot traffic, cattle, etc., that can cause displacement and coins, etc., can be repositioned to a deeper depth. Many other variables can effect 'depth,' but in most natural and undisturbed sites that I search, even older coins to the early-to-mid 1800's are found anywhere from surface to about 4".
By the way, I usually work all my detectors at, or as close to, maximum Sensitivity as I can, and I only reduce them if necessary to eliminate 'noise', if present, from EMI and other causes when the coil is at the operating height of about 1"-2" above the ground.
Monte
but even so they would have a consistent signature ? but then rust ? oh dear I am depressed already..
might need it..
