Widescan or Concentric

[smileysauce]

What is the main difference between the widescan and concentric coils? Will a widescan (double D) go deeper?

 

[Scully]

Generally speaking, double D coils will give you better deapth than a concentric coil if your soil is moderately (or higher) mineralized. In good soil there is not much difference between the two, but a double D does give you better coverage (front to back).

 

[JB(MS)]

In the low to moderate mineralization in this and surrounding areas concentrics are deeper than widescans (DD's) of the same or similar size, and also discriminate better. In tests we did in mild ground comparing 5.5 and 8 inch concentrics to a 6X9 widescan showed the 5.5 to be a little over an inch deeper and the 8 inch over two inches deeper than the widescan on inground coin size targets. In moderately heavy to high mineralization the widescan has an edge but still doesn't discriminate as well, especially anything rusty and round. The coils we compared were a different brand but here's what James and Vince Gifford said about Tesoro widescan coils in response to a DD vs concentric coil question on the Tesoro forum at Tesoro.com, and also a link to the thread the info below came from.

<b><i>"Stick with the concentric coils. Concentric coils are overall better discriminating coils. They are used mostly for coin and relic hunting. Wide scan coils on the other hand are designed to work in the heavier mineralization. Then wide scan "sees" 30% less ground effect that a concentric, but does not discriminate as well. The wide scan may also affect the readings on your Cort

 

[Mike Hillis]

And that is ground coverage at depth. While it is always ground specific, I can know what type of coverage I am getting at a particular depth with just little bit of experimenting. If I know that at one site I'm getting 4" of coverage at the 6" depth mark with the 8.5 Widescan, that can mean a lot. I can be more certain of my overlap and more certain that I'm not missing much down to that level. Once you get below the 6" mark its mostly hit and miss with most concentric coils. Typically the more pronounced the ground mineralization becomes then the more restrictive the detection field becomes for both concentric and wide scans.

Also if you are hunt modern sites, ground coverage and target separation is more important than depth and widescan's excel in this type of environment.

HH

 

[JB(MS)]

True, at least mostly . I've had a lot of concentric and widescans since I began detecting 37 years ago, have several of each now, and like using both but if I had to choose between one or the other for my ground conditions and the way I hunt the concentric would be my choice. The widescans bowl shaped field does give a wider scan from a couple of inches down to it's maximum depth (effectively creating an illusion of more depth than is actually achieved) than the concentrics cone shaped field, but no question the concentrics are deeper than the widescans I've used in the mild ground here--plus they discriminate much better. Just have to make sure to overlap properly when hunting older sites when using a concentric.

 

[Jackpine Savage]

As a general rule of thumb, it is said that widescan (DD) coils get about 80% the depth of a similar size concentric coil in typical US ground conditions. Round widescans generally go deeper then the elliptic versions. The elliptically shaped DD coils concentrate the EM field making them more sensitivity to small targets which is why they are the preferred for gold detectors where sensitivity to small nuggets is required.

When I had the Lobo ST I used the 8 1/2" round widescan quite often, preferring it over the stock DD coil for general hunting.

Tom

 

[Neil]

When I did comparisons with a CZ3D and a Sov XS at an ocean beach, the Sov would get coins nice and deep and still hit them a good 4" plus across the coil whereas the same depth coins the CZ would only see them on one small spot.
The CZ would definetly hit dimes and gold deeper but the coverage was terrible and on the beach coverage is really important. I really wish Fisher had developed some DD coils for their CZ line.....so many years and so few coils.....

HH
Neil