Detection distance, ground vs air

[Qiaozhi]

We do not discuss LRLs in the Geotech forum. Please go to www.longrangelocators.com if you wish to talk psuedoscience.

The LRL brigade use the term "halo effect" to describe something different to normal metal detectorists. The usual definition of the "halo effect" is the situation where salts in the ground [apparently] interact with a coin, thereby making it appear larger to the detector.

Although some coins do interact with salts in the ground, and iron certainly does, gold and silver are only affected to a miniscule degree, and often not at all. There is certainly no so-called "halo effect" as far as gold and silver are concerned.

Unless the ground is particularly benign, a VLF detector will lose depth in the ground due to absorption. In fact, some VLF detectors can lose as much as a third when compared to an air test. By comparison, PI detectors will experience much less depth loss in the ground.

[Koala]

Doesn't happen very often. Twice I can think of in thousands of artefacts recovered

A nice clean beep for an artefact that's beyond air test.

This one sticks in my mind as it was this summer and the ground was rock hard.

after chipping away at the ground for ages up pops a very small thin lead token. Well past the depth of my pinpointer so 12"-15" thought it must have come from the side so placed it back in the hole still a nice clean loud beep.

without the token in the hole there was an iron grunt a few inches to the side. Is there some sort of inter reaction going on. Or maybe a larger deeper target under the original?

[Tibuck19]

a VLF detector will lose depth in the ground due to absorption. In fact, some VLF detectors can lose as much as a third when compared to an air test. By comparison, PI detectors will experience much less depth loss in the ground.

That might Explain why I don't seem to dig things lower then 6 inches unless they are Old cans, As for VLF vs PI, Is that due to PI's, having lower frequencies? thus having more time to penetrate the ground?

[kt315]

Hey Aleximes

I am glad finaly to find one smart person here which has comfirmed existence of "Tha Halo" effect,
---
and a god of you is Flying Spaghetti Monster. we all know that good! LOL!

[qute1]

Sometimes called the "wish" field........... and only found whilst in a kneeling position and with buns perpendicular to the earths parabobalot aural haze.......

[Qiaozhi]

That might Explain why I don't seem to dig things lower then 6 inches unless they are Old cans, As for VLF vs PI, Is that due to PI's, having lower frequencies? thus having more time to penetrate the ground?

Most targets exist within the top 6 inches of soil, plus iron masking prevents a lot of targets being found deeper.

I think the differences between VLF and PI detectors are due to fundamentally different technologies. VLF detectors use balanced coils, which are essentially a loosely coupled transformer system. Any metal target will cause an imbalance in this [balanced] system, producing an audio response, whereas a PI detector relies solely on eddy current detection in the target. This seems to be the case because a PI uses much greater amplification than a VLF. In fact, so much so that it is necessary to provide a method of eliminating false responses due the coil being moved within the Earth's magnetic field.

If you take a VLF detector that has been perfectly ground balanced, and then use it in neutral soil, there will be no response from the GB channel. However, the DISC channel is still being affected. Motion detectors reduce this effect by only detecting fast changes due to metal targets, and suppressing any small changes to the ground matrix, or relative movement between the coil and the ground surface. For a PI, the target signal is unaffected by the same neutral soil. In my opinion the soil presents less losses to a PI due to the different detection mechanism.

[kt315]

VLF detectors use balanced coils, which are essentially a loosely coupled transformer system.
--
VLF detector of Andrej Schedrin does not use balanced coil, there is monocoil.

[WM6]

People here don't listen self proclamed Gurus from bananarepublic Slovenia or whatever else who said
BIG LIE that "Halo effect is interaction between earth mag. field and coil mag. field". Halo is a REAL and
EXIST whatever you want it or no.

Where in my answer to Alexismex (not "Alexismes" as you in rakija-mes wrote twice) did you read something about so called "halo effect"?

I am answering exclusively to the third (3) indent of Alexismex post. So you citation is pure lie and fraud as all your LRL compilations.

Halo effect is long known real phenomena (I checked it also many times) and has nothing to do with your religious LRL phenomena.

Reality of your claimed LRL phenomena is as much factual as "halo effect" in my previous answer. Both are your alcoholic delusions only.

I am proud to live in banana republic Slovenia.
You are evidently not proud to live in banana republic Serbia, cause you hide your origin in your personal info.

[Qiaozhi]

VLF detectors use balanced coils, which are essentially a loosely coupled transformer system.
--
VLF detector of Andrej Schedrin does not use balanced coil, there is monocoil.

The only commercial VLF detector that I know of, which uses a mono coil, is the Minelab GO-Find.
I searched for Andrej Schedrin on the forum and found a link to one of his books, but it's not in English, and I couldn't see any relevant schematics.
Can you post the schematic here?

[Nexus]

Ok guys. So many great opinions on the subject. Please tell me what effect is the one you see on the video below? Coin been detected louder in the soil than it is in air with the same settings.
Watch carefully from 7.05 to 7.18

[Tibuck19]

VLF detectors use balanced coils, which are essentially a loosely coupled transformer system.
--
VLF detector of Andrej Schedrin does not use balanced coil, there is monocoil.

Andrej Schedrin Vlf with a monocoil ?? and you belive because it is a mono coil it acts more like a PI detector when it comes to ground penetration, but with the benefits of a VLF discrimination ?

[Tibuck19]

The only commercial VLF detector that I know of, which uses a mono coil, is the Minelab GO-Find.
I searched for Andrej Schedrin on the forum and found a link to one of his books, but it's not in English, and I couldn't see any relevant schematics.
Can you post the schematic here?

Isnt the Go-Find a introduction model to Minelab's metal detectors? meaning the mono coil is not all it's cracked up to be ? I have seen lots of china knock off of the Go find on Ebay.

[kt315]

Andrej Schedrin Vlf with a monocoil ?? and you belive because it is a mono coil it acts more like a PI detector when it comes to ground penetration, but with the benefits of a VLF discrimination ?

i mean first his design, not Tracker-PI-Koschej-2..3...4...5-Clone you mean that is yes PI.

[Qiaozhi]

Ok guys. So many great opinions on the subject. Please tell me what effect is the one you see on the video below? Coin been detected louder in the soil than it is in air with the same settings.
Watch carefully from 7.05 to 7.18

Interesting video. It seems to confirm the idea that VLF detectors [in general] have less detection depth in the soil when compared to an air test.
I'm not sure why the Nexus would show the reverse, unless the coil balance is being affected in some way by the soil matrix, but I'm guessing you already know the answer. Hopefully you will share it here.

[Qiaozhi]

Isnt the Go-Find a introduction model to Minelab's metal detectors? meaning the mono coil is not all it's cracked up to be ? I have seen lots of china knock off of the Go find on Ebay.

Have a look here ->
http://www.geotech1.com/forums/showt...hlight=GO-Find

The interesting stuff starts from post #32.