F75 10" concentric and 11"DD coils

[WV62]

I do quite a bit of testing of coils on my F75 and I got a used 10" concentric coil this past summer and hunted with it a couple of times but after running the 11"DD the 10" concentric seemed so little I thought 10" couldn't be all that deep of a coil. So I kind of went back to the 11" thinking it had to be running a lot deeper.

When I got around to testing the 10" I was surprised it is giving me numbers a tad deeper than the 11" coil.

I hate to admit this one, but on my first time out with the 10" I hit a silver dime at about 7" and the first thing I did was switch to the 11" coil thinking I would do better.

I haven't tested the target separation on the 10" yet, but I am pretty sure it will not be better than the 11".

Any thoughts on this?

Ron in WV

 

[basstrackerman]

That's interesting and id love a reason to buy another coil lol.

 

[Elton]

Perhaps the 10" concentric shrinks the out-put area , and shoots it further into the ground on a slightly smaller area.

Years ago almost everyone claimed more depth with concentric over the DD coils.

 

[REVIER]

Very underrated coil.
Many get an F70 with the concentric and take the advice to sell it right away and get the big DD.
Most that use an F75 never had experience with the elliptical concentric.
Both big mistakes in my book.
Concentrics can have a scanning field that goes as deep as a comparable size DD or deeper...it is just not as wide down deep.
Target separation seems to be excellent on the elliptical concentric in both trash and iron.
The sound and response on the concentric is better than on any DD...don't know why, it just seems that way to me.
I think the bigger DD is slightly deeper, deeper by at least a couple of inches in great soil but in my mineralized soil and maybe yours to I get the same depth on both.
The better ability DD's are supposed to have in mineralization I believe has a lot to do with how much mineralization...a little it works better, a lot and all coils performance levels are curtailed.

You found silver and immediately switched to another coil....not something I would have done.
Ya gotta go with what works and that concentric just does...I will never get rid of mine and it is a prime and beloved member of my arsenal.

 

[REVIER]

On the other hand....
That larger scanning field down deep on the DD can make a difference, not referring to depth but just the greater coverage.
bruinvikes on another forum got an F70 with the standard elliptical and he lives up in Ohio.
He has a great site near his house that had a school that is knocked down now, and we think old homes were here long ago before that.
The area is about 2 1/2 to 3 acres large.
He did pretty well with the concentric, found some great things as we adjusted his settings from factory and he was getting deeper and deeper in that great soil.
Then he wanted a bigger coil and went with the 10x12 DD on my recommendation.
I told him he would probably get a little deeper but the real advantage is going to be how many more signals he will come across both shallow and deep thanks to that larger field...it is just hard to miss much with a scanning field that wide.
The minute he put it on he did start to find more, 5-6" was his usual depth with the standard but the first hunt with the DD he scored a 1909 wheat at 8".
Till the weather shut him down recently he was pulling up some nice things from that 6-8" area that I believe the concentric could reach but the DD made them all easier to notice.
Again I believe it was the wider field that helped more, not so much the depth thing.
When I used the elliptical in great, mild Kansas soil getting to the 8" mark was no problem, even dug a few other things at 10" but the big DD got me past that to the 12-15" area which was rare but it happened on a few.
There I had full confidence the concentric could get me deep enough to find most targets, I used it and not just the big DD because it just "sounded" great to me every time I used it on all targets.
Again, in your soil the depth between the two might be the same as it is here in mine, only you can know with experience, but the area you cover per sweep will be improved so it can be considered an advantage.

 

[Jackpine Savage]

Gotta wonder what a nice round 10" concentric would do on the F70/F75)

Tom

 

[WV62]

Good question, wonder why they kind of moved away from round coils?

Ron in WV

 

[Rob in (Ca)]

Concentric coils for me, work best for Parks / sports fields / Tot lot, type hunting, Better ID, Dead on Pinpoint.

Now hunting for deep coins or relics a DD coil would be it.

 

[Jackpine Savage]

Probably because at the time First Texas came out with the T2 / F75 detectors DD coils were all the rage. We are lucky to have the concentric's that are available.

I doubt lobbying for more choices would do any good due to the cost of development. Supposedly a concentric coil is cheaper to manufacture vs DD's and may be part of the reason Dave J has stated that we will see concentric coils available on all future products. Perhaps then we will see a nice selection of round coils.

To

 

[REVIER]

I love the shape of an elliptical, kind of a squeezed down scanning field going up the middle like a DD...or it seems that way.
I swear that helps make it think it can work more than well in the target separation area, plus it handles pop tops easily and gets decently deep.

 

[Jackpine Savage]

I hear what you are saying as well. The 12XXX and 10.5" CZ coils have the oval inner receive coil and we always felt they gain a lot of signal on those one edge coins. Should get another CZ but I'm holding out for the new multi-freq machine that's been rumored about for a couple of years.

Tom

 

[jim tn]

Funny, Tom, I've been thinking about another CZ a lot lately, myself. Merry Christmas, all, jim tn

 

[WV62]

I am a big fan of the elliptical shape, I like the slim profile for better target separation and still get good ground coverage.

Ron in WV

 

[Bruinvikes]

I am a huge fan of both coils for different reasons. I like the DD for its depth for finding old coins. I like the concentric coil to find jewelry at parks and sports field sidelines. Honestly, I don't think you could go wrong with either coil. As REVIER had said, I recently purchased the DD, but I'm not letting go of the concentric either. I received a sniper coil as a Christmas gift the other day, so I'm looking forward to see what that coil can do too.

 

[REVIER]

I am a huge fan of both coils for different reasons. I like the DD for its depth for finding old coins. I like the concentric coil to find jewelry at parks and sports field sidelines. Honestly, I don't think you could go wrong with either coil. As REVIER had said, I recently purchased the DD, but I'm not letting go of the concentric either. I received a sniper coil as a Christmas gift the other day, so I'm looking forward to see what that coil can do too.

Well well...Santa got you a sniper for Christmas.
Now you match my coil selection and I can tell you that sniper gets deep and finds things...Lots of things at most any site but ya gotta overlap.
The small coil in my mineralized iron infested sites gets more swing time than my others but I do love switching between them all.
Like a different machine every time I change over and they all have their slight advantages and unique superpowers.

 

[WV62]

Bruinvikes,

I would be interested in which of the sniper coils you got for Christmas and how it works out for you.

Ron in WV

 

[WV62]

I am kind of thinking for me the 11" DD is kind of the odd coil out for my F75.

The 10" concentric seems to be a little deeper, and the 10" DD elliptical is about the same depth and an inch better on separation (2.125" to 1.125").

Now I would never get rid of the 11"DD because it is the stock coil that came with the detector, but I may give it some extra rest time in the coil bag.

Ron in WV

 

[Bruinvikes]

Bruinvikes,

I would be interested in which of the sniper coils you got for Christmas and how it works out for you.

Ron in WV

I received the Fisher 5" DD coil. I will let you know how it works for me after I use it on a hunt.

 

[WV62]

Bruinvikes,

I would be interested in which of the sniper coils you got for Christmas and how it works out for you.

Ron in WV

I received the Fisher 5" DD coil. I will let you know how it works for me after I use it on a hunt.

That's a good choice, I have 3 little coils the 5"DD, 6.5" concentric elliptical and a NEL snake. All are about the same depth, the little 5" seems to have the smallest foot print and that is a plus for that coil.

In a new area I like to cherry pick the silver with one of the bigger coils that we have been talking about and then go back with a little coil and clean house.

Good luck with that little 5,

Ron in WV

 

[Bruinvikes]

Bruinvikes,

I would be interested in which of the sniper coils you got for Christmas and how it works out for you.

Ron in WV

I received the Fisher 5" DD coil. I will let you know how it works for me after I use it on a hunt.

That's a good choice, I have 3 little coils the 5"DD, 6.5" concentric elliptical and a NEL snake. All are about the same depth, the little 5" seems to have the smallest foot print and that is a plus for that coil.

In a new area I like to cherry pick the silver with one of the bigger coils that we have been talking about and then go back with a little coil and clean house.

Good luck with that little 5,

Ron in WV

Thanks Ron!