Coil Selection

[kansas_jayhawks]

What coils would you suggest for an F75?

I believe it comes with an 11" coil ... are there any others that would be something one would want to pickup and add?

 

[WV62]

For me a must have is at least one of the little coils, either Fisher or after market. I like the little Fisher 5"DD and the 6.5" elliptical concentric, I also have the NEL snake is runs about like the 5"DD.

Ron in WV

 

[kansas_jayhawks]

For me a must have is at least one of the little coils, either Fisher or after market. I like the little Fisher 5"DD and the 6.5" elliptical concentric, I also have the NEL snake is runs about like the 5"DD.

Ron in WV

My ignorance shows - what are the benefits of the smaller coils?

What does "DD" stand for?

Thanks

 

[lytle78]

Smaller coils see less ground. Two advantages with that, less ground noise and better separation between adjacent targets.

DD coils are better at separation - the downside is that concentric coils ID better and might be a bit deeper.

 

[Jackpine Savage]

+1 on the 6.5" elliptical concentric.

Tom

 

[D&P-OR]

Snake DD

 

[WV62]

For me a must have is at least one of the little coils, either Fisher or after market. I like the little Fisher 5"DD and the 6.5" elliptical concentric, I also have the NEL snake is runs about like the 5"DD.

Ron in WV

My ignorance shows - what are the benefits of the smaller coils?

What does "DD" stand for?

Thanks

DD stands for Double D, which is the construction type of the coil. With a DD coil if you could see inside the wire windings look like 2 D's with the straight sides back to back. So if you look at a picture of the stock 11"DD coil you will notice it has a straight thick bar down the center of the coil and is curved on the the outer left and right. So with a little emanation it looks like 2 D's back to back. Now that straight bar down the middle of the coil is the hot detection area of the coil which gives better target separation.

Now a concentric coil is made different no mater the the shape of the coil, elliptical, round or oval. These coils still have 2 windings of wires one big one and one small and small one is inside the big one. The detection signal of the coil is like cone and goes down into the ground ending in a point. So if you can get a mental picture of that you can see why the concentric does not do as good a job as a DD coil in separating targets.

In both types of coils there are 2 coils of wire one sends the signal and the other receives the signal back to the detector.

As stated above the little coils will see less ground and less targets at the same time, so the separation is better. The trade off is the depth, the small coils will not detect as deep as the big ones.
So if you are hunting nice clean ground (not a lot of metal trash) the big coil would be the best choice. If you are hunting in a trashy area the little coil will give you a better shot at finding something good in close to the trash.

Ron in WV

 

[jim tn]

The 5" DD Fisher is a laser! A must have coil for the serious trash hunter. HH jim tn

 

[REVIER]

Love my Fisher 5" DD!

 

[nalc472]

Gotta have the 5 inch stock coil.

 

[markg]

The stock 11"DD coil is the very best all round coil. Extremely fast, between target recovery and very deep to boot. There is a definite advantage of the small 5" coil when working the heavy trash. Amazing what I've pull out in the trashy areas where everyone seems to avoid.

 

[Mike Hillis]

I have the 5" DD, the 3x6" concentric, the 5x10"DD, the stock 11" DD, and a 10X14" RIF Ranger DD.

I find I use the 5x10 DD the most and split the rest of the time between the stock 11" DD and the 10x14" Ranger. The 5" and the 3x6 see hardly any use. If I coin hunted more I'd probably use them more.

HH
Mike

 

[Jackpine Savage]

Mike

I don't have anything in the 5x10" size range, probably will get one as I liked the performance of the Nel Sharpshooter on the T2 Classic. For a larger than stock coil I went with the 10x13"Mars Tiger.

Now just have to wait for the ground to thaw out.

Tom

 

[markg]

I have the 5" DD, the 3x6" concentric, the 5x10"DD, the stock 11" DD, and a 10X14" RIF Ranger DD.

I find I use the 5x10 DD the most and split the rest of the time between the stock 11" DD and the 10x14" Ranger. The 5" and the 3x6 see hardly any use. If I coin hunted more I'd probably use them more.

HH
Mike

Always wondered about the 5x10 DD coil, but been reluctant in buying another coil. Thought I might try one in the future. I got on board with the very first F75 and still today reach for it when going most places. I too have found very little use for the 5" DD coil except for the super heavy trash areas. The depth really drops off with this coil in my bad ground. I might have to ask Tinfoil to let me try his for a week and see if it is an asset.

 

[MI-AuAg]

What coils would you suggest for an F75?

I believe it comes with an 11" coil ... are there any others that would be something one would want to pickup and add?

If you are buying the current F75 Ltd, it comes with the 5" round, as well as the 11". That is all you will need for most applications. At it's recently reduced price, it is an excellent value IMO.

At some point you may want to add a larger, or intermediate size, but, those two will be all you need for most situations.

 

[Mike Hillis]

Its hard to take the 5x10 off the F75. I bought the the 10x14"Ranger coil because it was the longest, narrowest coil I could find for it. I'm hoping the Deteck 8x14 WSS will get around to the F75 someday. I'd like to see the 7.8 kHz 11" teardrop get tuned for the F75. I like that coil.

All these aftermarket companies making the same size coils is funny. Like their coil is really going to be different from the same size coil from the mfg or the three other after market mfgs making the exact same size.

HH
Mike

 

[Jackpine Savage]

It is kinda funny that when one comes out with a new coil shape/design the others follow suit. I prefer the Mars because of the shape and lighter weight vs some of the others. Then Nel came out with the Thunder in a similar configuration and it weighs less than the Tornado!

 

[Galen1066]

OK, I'm in the process of getting the F7LTD combo set, but I was also offered a 15" coil for an additional $200 or so, and was wondering if it was needed for someone just getting into the hobby, from all that has been said, I don't think so, but I was told by another avid searcher that the larger the coil, the deeper you can scan, any opinions?

If you are buying the current F75 Ltd, it comes with the 5" round, as well as the 11". That is all you will need for most applications. At it's recently reduced price, it is an excellent value IMO.

At some point you may want to add a larger, or intermediate size, but, those two will be all you need for most situations.

Thanks in advance for your insight.

 

[Mike Hillis]

I'd wait on the 15" coil. If its the 15" Fisher coil, I haven't heard much good about it, and 15" is a pretty big coil that could actually turn into a $200 boat anchor. If you decide you do need a larger coil after you get some time under your belt you can get the 13" Ultimate. It has good reviews, very light weight and won't cost $200 dollars.

HH
Mike

 

[dfmike]

I like my Detech Ultimate but I've noticed that is doesn't ground balance with the same numbers as the 11 DD on the F19. That's strange. Where I found my standing liberty, the ground balance number indicated above 80 with the 11 DD but just slightly over 70 with the Ultimate. I tried different areas around the vicinity with the same results or just about. I get good results with both generally but the lower numbers on the Ultimate are kind of strange. The NEL Thunder was the same as the Ultimate, lower numbers for ground balance. Perhaps the high ground mineralization has the bigger coils fooled for some reason ?