Coil dead zone

[Mark-VA]

I know this is not a normal symptom.
On a DD coil the area from the front tip down 3" is dead to low conductors. In other words I can air test 3 different pieces of gold and the machine fails to respond (even less than 1/2” from coil) until the targets are more than 3" under the coil. No other coil I have does this and I'm sure it is not the norm.
Would this be caused by improper winding patterns in the front of the coil?
High conductors are not affected or I might say it is not as noticeable.
Other coils are not showing this problem on the same machine so the machine is fine.

[Mark-VA]

I think I have my answer.
The overlap area from the TX and RX windings.
It is a common occurance, or more common than I thought.

[dfbowers]

I think I have my answer.
The overlap area from the TX and RX windings.
It is a common occurance, or more common than I thought.

I think I know what you are referring to. I noticed this with a DD coil that I have for my Shadow X5. I even had a discussion with Troy Gallow regarding this because one of my posts was misinterpreted and he didn't seem happy about my post. Anyway, your targets need to move through the detection area to get to this "dead zone", correct? If so, then there is not issue, except for pin pointing.

[Mark-VA]

The area from the very tip down 2 3/4", moving toward the center of the coil has a very weak response. I can only confirm this with the lower conductors/smaller mass. Doesn't seem to affect targets with more mass. I confirmed this on two different machines using the DD coil.
Still interesting to know.