Dual field coils

[Mark-VA]

Is the White's SL 12" dual field coil basically two mono coils, one small in the middle and the larger one on the outside?

[kt315]

yup. one coil splitted in the two. try dig the forum and ll find the info.

[Mark-VA]

Is it possible, using a toggle switch, turn off one of the coils and in a simple term have a single mono coil?

[Carl-NC]

It's possible to design a coil like that but not possible with the DF coil.

[Mark-VA]

That answered my question, thanks.

[Mark-VA]

Can't help but to wonder why the DF coil would not work?

Hey that is the only way to learn.............

[kt315]

Is it possible, using a toggle switch, turn off one of the coils and in a simple term have a single mono coil?

do you mean TO OPEN the coil and to change a connection by switch?? for what??

[Mark-VA]

I was thinking more along the line of breaking one lead inside the housing where the cable is connected and adding a toggle switch. And leaving the other pins the same.
But Carl says it can't be done with the DF coils.

[kt315]

same quation. FOR WHAT? do you want to get more depth? what what you want???????

[Mark-VA]

Seriously looking to make a mono coil that would be better relic hunting in the heavy iron trash. The 12" DF see way to much.
And of course I don't won't to loose 1/2 my depth to acquire the results.
My understanding, well not mine but advise given by Reg is that a mono coil will not be as sensitivity to the very small pieces of iron.

[Carl-NC]

The DF coil is made of 2 low-inductance coils in series that add up to ~300uH. If you split them and run just one, the inductance is too low. Also, you would likely need to replace the cable as the second coax line is clipped off. In short, start over from scratch.

Edit: The cable comment was assuming you wanted a switchable large-small coil, a la Garrett BFO. I think that's not the case in re-reading, I think you just want to kill one of the coils. Again, the inductance will be too low.

[kt315]

you are not on right way. try order a housing from a geotecher and do the coil yourself as you want to get.

http://www.geotech1.com/forums/showt...um-table/page3

[Mark-VA]

Thanks Carl, now I understand why it won't work.

The DF coil is made of 2 low-inductance coils in series that add up to ~300uH. If you split them and run just one, the inductance is too low. Also, you would likely need to replace the cable as the second coax line is clipped off. In short, start over from scratch.

Edit: The cable comment was assuming you wanted a switchable large-small coil, a la Garrett BFO. I think that's not the case in re-reading, I think you just want to kill one of the coils. Again, the inductance will be too low.

[sirbedevir]

Hello!
I have a 2×2 meters double frame: lower transmitter-receiver. upper counter turn compensation coil - connect inline to preamp.
I use it with PulseStar2pro and homemade Delta Pulse - and it works well, reduce powerline noise.
But!
I try it with my new homemade Superscan clone, and make more noise!
This compensation coil not works with differencial opamp system detector, like Superscan, Minipulse, Hammerhead?

[Orbit]

Hello sirbedevir !
What are the inductance coils on the picture ?