Question on Coil selections for the X70...

[Doug[Manila]]

I have a question on the favored targets under the coil selection tables found here... http://www.findmall.com/read.php?55,612930,612930#msg-612930

Does this mean that the 9 inch coil marked BGL (brass, gold and lead) cannot find silver? I think not but I guess it does mean that it is less hot on silver. How many inches more can the 9" coil marked BCS find a silver dime?

 

[nero_design]

I think you'll find the chart suggests that the High Frequency coils (18.75khz) don't indicate Silver either but they CERTAINLY do detect it just the same.
You are referring to a High Frequency coil. The frequency allows you to penetrate different soil conditions. High Frequency coils allow you to punch through highly mineralized soil conditions so if there's a silver coin buried in mineralized soil, the HF coil is the one which will likely find it. But on neutral ground, the Medium Frequency coil might have an edge over the HF coil.

Medium Frequency coils appear to favor Silver ...and the Higher Frequency coils favor Gold.

Any coil will detect metal. And any of the coils will detect silver. But if you are specifically hunting Silver coins, the coils suggested in the chart are going to
have preferred targets to which they are slightly more sensitive to. My Medium Frequency coil likes Silver just as much as my High Frequency coils but it appears that whoever put the chart together (BB?) had noticed a slight preference for one coil over another in relation to sensitivity to particular metals.

 

[Steve in Idaho]

I have a 7.5khz DD 10 1/2" coil that I use all of the time and I have found small gold nuggets (1/2 gram) and lots of silver coins with it. I think that a lot of it is to knowing your detector and how to use it.

 

[mndigger]

Hi i'm new to this forum, and have a new X70 that I purchased a few weeks ago,
what i've been reading about the DD 10.5 inch 7.5khz coil seems to be very good and was wondering if I should purchase it
and basically learn with it rather than learn with the concentric coil and then have to relearn with the DD coil, what's the concensus on this?
and where is a good place to buy it and what would be a good price?
Right now I have the option of getting the 5x10 eliptical coil as the pro package with the minelab carring bag for a hundred bucks but if my
money would be wiser spent on the DD 10.5 inch 7.5khz coil then thats what I would rather do, I could sure use some pros and cons to better
weigh my decision.............i'm leaning toward the DD 10.5 inch 7.5khz coil.
Thanks in advance

 

[coinsh00ter]

Mndigger,
What type of hunting are you doing? I personally think the first extra coil should be a 6 inch coil, some prefer the DD, I use the 7.5khz concentric. It does a great job separating out trash. I do have a 10.5 18.75khz dd coil, but have only used it at some trashy homestead sites, that are better suited for the smaller coil.
Dave in NJ

 

[mndigger]

Beach hunting, some parks and old homestead sites and once a year we go to Mytle Beach SC for two weeks
and i will be using it there.

 

[coinsh00ter]

Maybe others can comment, but my suggestion for optimal for your conditions would be:

Beach Hunting: 18.75 10.5 dd coil the 7.5 10.5" close second, both will cover the extra ground at a beach. 18.75 is supposed to be hotter on gold, and iron trash usually isn't very prevalent at salt water beaches.

Old Homesites and parks depend on the amount of trash. You may get very frustrated learning with a larger coil at a very trash site, and will probably miss some targets. Most coins will be found in the range of either 6 inch coil. I have found the higher sensitivity you can run a 6 inch coil, more than compensates for the increased depth of larger coils that my get too hot when you up the sens.


If you are hunting a public park you may not want to dig everything, as to not have people complaining. With my six inch coil, I can either use a small plug or probe and get to coins with little lawn damage.

 

[mndigger]

Thanks coinsh00ter for the info, points well taken.
is the 10x5 a DD coil?

 

[rifleman]

Yes the 5 X 10 18.75mhz is a DD coil. It is also the only coil Minelab makes for the 70 that is not waterproof. If you search for the thread, it can be made waterproof with just a little work for your beach use.

Good hunting, John K

 

[Digger]

Whether or not I would use the 10-inch round DD coil would depend on the mineralization of the sites I was hunting. My unscientific "rule of thumb" is the number 28. If I can GB my concentric coil with a GB number of 28 or higher, I use the concentric. If, however, the mineralization requires me to GB with a number less than 28, I get more performance out of the DD. Simply a matter of coil design characteristics.

As to having to learn one coil or another....... there is very little difference in the way you use them. I do try to overlap my swaths with the concentrics more than with the DD coils. Again, it is a matter of design characteristics. One exception is in pinpointing with the two types of coils. Since the "hot spot" on a concentric coil is in the center, I can X over a target and get a good idea as to where it is buried. On the DD coils, the "hot spot" runs the entire length of the coil, front to back, right down the middle. So, when I am "Xing" the coil over a target, I slowly pull the coil closer to me. When the sound drops off, the target is directly under the front "tip" of the DD coil.


The price you mentioned for the bag and elliptical sounds fair. Of course it would depend on the condition of each. Whether or not you will find it your best option would depend on what you hunt for. The elliptical coil is a great coil for beach hunts (if you water proof it first) and some use it for prospecting. My brother uses his for coin shooting open fields as it has a solid bottom (don't snag) and covers a lot of ground. Personally, I don't think it has the depth of detection of the 10-inch round DD. And in my moderate mineralized soil, it don't have the depth of the 9-inch concentrics. If you give us an idea as to what you are looking for, and the type of places you are hunting (including mineralization), we'd be better able to answer your questions. HH Randy

 

[mndigger]

Thanks Digger that is a good rule of thumb for ground balancing,(i will try it) as far a what i'm looking at in mineralized soil i dont know.....i live in minnesota
and right now our ground is still frozen, so i haven't been able to take my new x70 out yet, but i assume we have pretty mineralized soil (whatever that means) as we are known for our iron ore deposits, so as of now i dont know yet what to expect as far as mineralized soil........i do believe i bought the best detector to handle whatever it might be i just have to learn it and it will serve me well.
i will be doing a lot of fresh water beach hunting.........land of 10,000 lakes........ and i really like relic hunting old home sites and....... some parks in that
order.
i will be purchasing another coil just not sure which one to get, is the 10.5 dd 7.5khz that much better than the 9.5 that comes with it as far as depth? i realize
there are probably not any pat answers to these questions but this is what is going on in my mind, im just like anyone, i want my dollars to be
used wisely. coinsh00ter mentioned the 6" coil and got me to thinking that i probably will have to add that to my list but as the next one i dont know.
i do really appreciate all that have given feedback and have i gleened a lot from this forum.
Thanks Digger and Everyone else
Mike

 

[mndigger]

Thanks Digger that is a good rule of thumb for ground balancing,(i will try it) as far a what i'm looking at in mineralized soil i dont know.....i live in minnesota
and right now our ground is still frozen, so i haven't been able to take my new x70 out yet, but i assume we have pretty mineralized soil (whatever that means) as we are known for our iron ore deposits, so as of now i dont know yet what to expect as far as mineralized soil........i do believe i bought the best detector to handle whatever it might be i just have to learn it and it will serve me well.
i will be doing a lot of fresh water beach hunting.........land of 10,000 lakes........ and i really like relic hunting old home sites and....... some parks in that
order.
i will be purchasing another coil just not sure which one to get, is the 10.5 dd 7.5khz that much better than the 9.5 that comes with it as far as depth? i realize
there are probably not any pat answers to these questions but this is what is going on in my mind, im just like anyone, i want my dollars to be
used wisely. coinsh00ter mentioned the 6" coil and got me to thinking that i probably will have to add that to my list but as the next one i dont know.
i do really appreciate all that have given feedback and have i gleened a lot from this forum.
Thanks Digger and Everyone else
Mike

 

[rifleman]

If the areas you hunt have a lot of trash, I would get the 6" DD coil. It sounds like your area might be mineralized and the DD coil works better in those types of areas. The little coil really does a good job at getting around the junk to make the good finds. Some places were darn near impossible to hunt with the stock 9" coil. The little coil earned it's keep in those areas. I have found dimes and pennies at 6" plus with the little coil. All gave good solid tones and I'm sure it would have detected the coins deeper. As was mentioned, you can run the sensitivity up pretty high with the 6" DD. If there is not too much junk, I like the 10.5 7.5khz DD for depth. One post I read from a Minelab dealer in the midwest says his deepest finds are with the 3khz coil. I've not tired the 3 khz coil, but sure do like the 10.5 7.5khz DD. A friend let me borrow his and as a result I just bought one for myself.

Good hunting, John K