DD loops arrangment

[m23585]

Another noob question. Because Tx and Rx loops in this design have to overlap, does it make any difference which loop will be on top? Thanks

Greg

[joop]

In my opinion, no!!

[m23585]

Well, that's what I think. But in the book, one of the examples say, place Rx on Tx. So, I was wondering if it makes any difference?

[WM6]

This is more of personal preference than real difference in praxis.

With RX on TX you get some fixed distance between soil (say if you lead coil touching soil) and RX coil, which can lower parasitic capacitance effect between (very sensitive) RX coil and soil.

On other side TX on RX can be (theoretical) a little more sensitive (question of small difference in distance between RX coil and target).

[Qiaozhi]

Well, that's what I think. But in the book, one of the examples say, place Rx on Tx. So, I was wondering if it makes any difference?

It only says that in the book because the TX loop was fixed into the coil shell first, leaving the RX loop to be adjusted. It could have easily been the other way round. In practice there will be no discernible difference with the TX on top or the bottom.