wide scan vs concentric question......

[JimGilmore]

First off my understanding is that the coils on the GB are wide scan or DD.
Most pictures describing the search pattern for a concentric is a cone under a coil. such that at it's deepest you are pushing a very small spot along the ground.
What I am wondering is how the DD really work in regards to shape and pattern of it's coverage,,,
I think the idea is that it is more like just a line from toe to heel.Being swung side to side.
But I am wondering if you could view it from the side. Would you have a triangle of coverage where things closer to the center are able to be picked up deeper . Or is it more of a consistent depth from front to back the whole length of the coil ??

 

[Dave J.]

All pictures of the detection pattern of searchcoils are uninformed imagination at worst and gross overgeneralizations at best. The detection pattern depends on the target and its lay in the ground just as much as it does on the searchcoil.

For equal overall geometry (size and shape) a DD will tend to have a longer and narrower search pattern than a concentric, for objects shallower than about 1/2 the length of the searchcoil.

There are many other differences between DD and concentric, but that's what you asked about.

This is the GB/G2 forum, and the GB/G2 platform is designed specifically to work with DD's. Questions what it might do with a concentric are almost irrelevant. Some individual concentric searchcoils have been mated up to specific individual GB/G2 machines and have seemed to work OK according to the customer. It's just that customer's luck. We'd gladly sell our "Fratbros" concentrics as accessories for the GB/G2 except for one reason: we can't tell a customer that the darn thing will work. The GB/G2 platform is not designed for use with concentrics.

--Dave J.

 

[JimGilmore]

Dave J thanks for the answer... I was though trying to figure out what the shape of coverage would be.
I realize that the GB does not have nor meant to use a concentric..but that it(the concentric is always said to have an ice cream cone type detection pattern...It was just meant as a point of reference....
Same idea I was wondering about the DD.
I was wondering if a DD's pattern would tend to be more flat along the extreem depth ,rather than going to a point?

 

[amberjack]

thanks Dave.

i know its good at pulling coins out of junked up spots today i found myself saying "you rock gold bug" guess its like anything practice using the machine and targets being there. if i look back at my older posts i was going to chuck it in the bin, now it comes everywhere with me

AJ

 

[rockpup1]

Was wondering if fisher is going to produce some more DD coils for use with the Gold bug pro/se.I see the F75 has a new 15" coil-could this not be adapted to work with the gold bug pro?

The 2 coils it has are great and I would not mind a 8" round DD,but from what I hear the 11" is very amazing at seperating targets.

I been waiting since seeing the 15" for the F75.I would much rather have a 15" coil over the 11".