Which brings up a good question,

[Hobojo]

I recently received my " wide scan " coil from our favorite soon to be makers of the NOW famous and unspoken detector the Tesoro Caz.... ,
What do they mean by "wide scan" ?
When I swing the coil its obvious that it is much more selective on the targets, able to pickout the good from the bad even when they are very close together. So it appears to this " knuckle head " that it is much more " narrow " in its operation. Then why the term " wide scan " ?
I know a little about radio, and I keep thinking of my coil as my " antenna " so the term "wide scan " confuse's me.
Antenna propogation can be vertical or horizontal, directional or omni-directional. It's my thinking that a Concetric coil would be more of a " wide scan " coil. And that the " wide scan " would be more of a vertical directional. Anyone else have thoughts on this subject? Below are some pics of Antenna propogation and their frequency spread,


See the difference. So why the term "wide scan"?

 

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[RobRieman]

Yeah very narrow scan is probably accurate. [emoji4]

 

[Terry Soloman]

The "Double D" coil, and the "Widescan" Tesoro variant, paint a wider search area compared to the snow cone-shaped search area of deeper Concentric coils.

 

[patpall22]

What i really want to know is if the dd coil detection field is in the middle strip, why would they make a round dd coil like the WOT? is their an advantage to the extra space like more wiring to make it deeper? It would seem to make it heavier and harder to get into tighter areas

 

[atomicscott]

What i really want to know is if the dd coil detection field is in the middle strip, why would they make a round dd coil like the WOT? is their an advantage to the extra space like more wiring to make it deeper? It would seem to make it heavier and harder to get into tighter areas

I believe one reason is the capacity for more windings that makes the round design useful. The average size of the coil still relates to average depth. I remember reading somewhere, that a 10" coil averages 10" on quarter (air test). 8" averages 8", etc...If you have a 10" x5" coil, the average is 7.5". If this is the case, the benefits of the round coil become more clear. I prefer the separation of the elliptical DD coils. You still get good depth but the tighter separation of a smaller coil.

 

[Hobojo]

Thank you all for the extra info, it hepls makes this hobby a little more fun when I think about all the engineering that goes into just making a coil.
It still appears to me that the DD signal is really a " narrower " field of radio waves out front. But it makes more sense as to why its called the wide scan, when the coil is swung to the side you actually have a " wider scan " of waves emitting in to the ground. Thanks for the visual Terry it helps.

 

[digger27]

The scanning field from a concentric coil is like an ice cream cone in shape coming off the bottom, (and top), of the coil, a widescan, butterfly, double D or DD coil, (all the same), is more like a book or blade.
Not exactly in real life, but these terms are most used to describe the field shapes.

I believe the reason for the term widescan is because at the end of the scanning field that cone shaped field narrows down to the size of a quarter, the DD coil stays much wider at depth.

 

[tabman]

The scanning field from a concentric coil is like an ice cream cone in shape coming off the bottom, (and top), of the coil, a widescan, butterfly, double D or DD coil, (all the same), is more like a book or blade.
Not exactly in real life, but these terms are most used to describe the field shapes.

I believe the reason for the term widescan is because at the end of the scanning field that cone shaped field narrows down to the size of a quarter, the DD coil stays much wider at depth.

Yep! You can scan a wider area of ground with each sweep of the search coil when using a wide-scan search coil.

It's debatable if a wide-scan search coil can separate better than a concentric search coil. I like searching the same area with each.

tabman