Yet another SEF coil question ?

[a.c.t.i.v.8]

Hello people, had the SEF coil out for the first time today, but found it hard to pinpoint! Wasnt to bad as I was on a beach, but did struggle. Does anybody know, where the pinpointing is ??


Dave

 

[Jason in TN]

Lay a coin on top of the ground and use it to learn could paint a spot on the coil where it pinpoints.

Jason

 

[Larry (IL)]

I would suggest holding the coil above the target by a couple of inches too. The SEF's I have tried don't like close targets, I got double beeps.

 

[a.c.t.i.v.8]

Both good answers thanks......

 

[Neil in West Jersey]

I also had a hard time with the D2, which is also a DD coil. As the coil size gets larger, pinpointing becomes even more challenging with these types of coils.

With a concentric coil, the sweet spot is centered under the middle of the coil, but with a DD the sweet spot actually runs from the front tip to the rear tip of the coil running along the center axis.

I found a nice graphic (on the green machine's corporate site) that made it easier for me. By understanding the signature pattern of the transmitted and received signals, it helped me to understand where the "sweet spot" is. The picture is a frontal view and a side view of a DD coil.


[attachment 151286 DDProfile.jpg]


I guess the one easy answer is there is no poinpoint spot on a D2. It runs along the center of the coil from the front to back. The center front tip when sliding the coil forward, the rear tip when coming back.

It is important, especially when using DD coils, to sweep from two directions.

 

[Pulltabs by the pound]

Awsome graphic Neil! Big help thanxs