Effectiveness of 12x10 coil

Hi all,

I'm buying a silver uMax as a spare detector for my Deleon this winter. I've noticed all the posts about the 12x10 and wonder if I should also buy one of these.

Has anyone done any testing to determine the actual increase in depth provided by the 12x10 over the stock 8" coil?



Well-Known Member
I have heard pros and cons? IMHO save your money. The stock coil on the DeLeon and the stock coil on the Silver will work on both. If I was to choose another coil for either it would be the small coil, Beale.
Thanks Beale, that sounds like good advice, especially the part about saving my money.

I already have a 4" coil that I've never used. I remember doing some air tests that suggested very little loss in depth between the 4" and the 9x8 on my Deleon.



Active Member
Hay Harry,

I have used the 12"X10", the 8", the 7", the 9"X8" and the 5.75",
all concentric.

The 12X10 has fewer uses than the other coils. The depth is not
effective for the most part because of masking and soil conditions.
It can not detect small objects if there is any masking, or tough
soil conditions. The 12X10 is nose heavy. I mount it backwards.

But, large iron and lower conductors can be found very deep under
certain conditions.

For instance, in a clean area, I thought I had a mini ball real deep.

I dug 18 inches just to recover a pull tab.

Another time I found a clevis at 24 inches,

The 12X10 can cover more area per sweep under areas with few


I recently picked up 10x12 concentric, pretty cheap so I couldn't refuse it. I hear some people claim more depth etc. I'll try it on the Silver and Eldorado, next spring after the ground thaws.

I am interested to see what the SEF coils are like for the Tesoro. They just cost so much, almost as much as the Silver.


Well-Known Member
The larger the coil the deeper they go at the expense of small objects.

What do you want to hunt?

Coins at 18" it will not do.

A buckle it may do.

Wider it will not Go.

If you want wider, go with a DD coil the same size.

Thanks gang,

That gives me a pretty good sense of the various pros and cons of this coil. Although I've decided not to get the coil this winter I can think of one site where it might help out.

I sometimes work an unbroken field for 19th century artifacts that have become more difficult to turn up and are also quite deep at times. Some extra depth at that location might be helpful.