VLF

[jesus]

I made a question another place this forum, but I believe here is the correct place by the people who post here in metal detectors relation. My question is if the VLF technology can detect 12 meters down ground with a big coil ( 1mx60cm), I know the problem with big coils, but in a link I found a turkish vlf detector and the vendor says this capacity. Maybe somebody in the forum can explain about VLF technology and this way we can understand and no be robbed with some kinds of claims. Thanks.

[Carl-NC]

Probably you can do it in an air test with a big enough loop and a big enough target. But VLF uses induction balance, and when you put the loop to the ground it becomes unbalanced due to mineralization. The bigger the loop, or the higher the power, the worse it gets. So ground depth may be much less. Because of this, super-deep detectors with big loops are usually PI designs.

- Carl

[jesus]

Thanks Carl for your input about my question. Carl: If we have a good ground balance device in our VLF detector can we get more power into the ground ?. Thanks.

[Carl-NC]

Not really, because GB doesn't cancel out the ground signal, it just moves it to a place where it is easily ignored. The ground signal is still there, and increasing the TX signal will quickly cause it to overload the RX circuitry.

- Carl

[jesus]

Ok. Carl, then we must wait for another technology wich let us go deeper.With this inputs I have saved some good money. Thanks Carl.