Difference between VLF and PI metal detectors

[SteelPat]

Ok well the main ones are VLF(Very Low Frequency) and PI(Pulse Induction). I was going to go into a detailed description for you but then found a post by Whites detectors that explains it all way better than I ever could. It gives you a pretty good run down on how both types of detectors work and the main differences.

http://www.whiteselectronics.com/the-hobby/knowledge-base/field-reports/how-metal-detectors-work

 

[Jaros]

Thanks SP. . I think that link is a great read for all members.
Jaros

 

[limpalot]

Maybe put it in Downloads, I read another explanation the other day on this site, was on a yellow background.
Cheers LL

 

[soggybottom]

Thank you SteelPat. The site explained it very well.

Cheers

 

[Digger58]

I have a question regarding taking two different detectors out fossicking.

If using a PI machine, does the VLF come out and go over the same ground already searched with the PI?

I can see the VLF being used on ground where a PI and a large coil would be awkward, and I can see how the VLF can be taken as a backup machine in case the PI plays up.

Cheers.

 

[Ded Driver]

If the ground isnt high mineral the VLF can be useful for finding small nuggets a big coil PI might miss, & also for species in quartz ground.
The VLF can also be handy if you're in a high trash area (if it has good discrim)

 

[AngerManagement]

So many variables but all depends on ground conditions and in HOT / heavy mineralised ground; a VLF is as good as useless, VS a PI.

 

[Digger58]

Thanks guys, much appreciated, cheers.

 

[RM Outback]

VLF are the early detectors and still current PI was released in 1994 and revolutionised metal detecting, Minelab were the first to release it to the market. Given Australia's high mineralised ground where the PI has been king since its release when looking for gold detecting it hasn't been challenged until the release of the GPZ. PI is just another great Aussie design that's proven to hold its own on the world stage :Y: :beer:

 

[BigWave]

I made my first mono PI detector around 1978, so am very surprised commercial units weren't available then.
Depth detection was great, but the ground balance was non-existent and the audio interface was woeful compared to those of today.
Still, it worked better than the VLF machines that I built.

 

[mudgee hunter]

Always good to have a spare. I've seen 4500's picking up tiny pieces using stock coil. It would have to be a serious size coil to warrant going back over it again with a VLF.
I would be leaning more towards a smaller coil to go over it again with the PI.
Could be wrong.
Perhaps if mention the two set ups, it might make for better informed opinions

 

[Guest]

I have a question regarding taking two different detectors out fossicking.

If using a PI machine, does the VLF come out and go over the same ground already searched with the PI?

I can see the VLF being used on ground where a PI and a large coil would be awkward, and I can see how the VLF can be taken as a backup machine in case the PI plays up.

Cheers.

Gday

As mentioned a high end vlf machine like the Fisher gold Bug 2 are good for getting small nuggets and species, but can't compete depth wise to a pi machine, they can also struggle to run quietly in some areas where the pi detector will almost always run quietly in hot ground, in some places if you cant get the detector to run quietly enough you will not hear the target responses, also with the introduction of machines like the sdc2300 running the standard 8" coil will find the same small nuggets and specimens that a vlf will and at better depths, so its debatable whether there is any advantage in using a vlf detector just for hunting nuggets.

I use a vlf minelab sovereign gt in goldfields areas as I like to hunt for coins and relics as well, so the advantage there is that firstly I can run it in "silent search" and secondly it has very good discrimination which allows it to be used effectively in trashy areas, I have never found any nuggets with it but plenty of old coins and such, the discrimination feature of the vlf machines is the main advantage that they have over the pi machines.

As a backup detector a vlf can be useful and handy to have with you if you want to just quickly check out places where conditions are tight, or as you say if the pi detector craps itself, which does happen :awful: , at least its not game over you can still get in some more detecting.

cheers

stayyerAU

 

[UnderEmployedGeo]

So, despite having already dabbled in PI machines, I have come back to being interested in detecting but this time I have bought a Nox 800 and a 6-inch coil.

WHY? Because I am more of an investigator, I like scratching around and looking in places I find interesting. I don't get out every week so a $5-10K machine is just obscene price wise.

Am I stupid?

 

[Muk]

Depends on what your looking for if its relics Nox is great if its gold Nox may not handle some areas because of the hot ground. I have a mate who is very expirenced detectorist that has a Nox 800 /gpz7000 he cannot use the Nox where we look for gold due to hot ground/ mineralization here in the Pilbara WA. Loves it chasing coins on local ovals and at the beach in Geraldton where he lives, he has tried it several times out on the gold but drives him crazy there may be other Nox users that can give you some better tips on how to use it in hot conditions but generally Pi detector is better in goldfields cheers muk.

 

[Goldtarget]

Not stupid but youll have to have a happy go lucky attitude and not be discouraged easily.

Mild ground, high recovery, all metal. For Gold a GM might have been a bit more suitable, but both need a can do attitude and a bit of patience.

You could get on the gold for less than a grand with the GM, and a half decent PI for under 2.

Best machine you can afford is the go on goldfeilds, but the 6 will double up as a park and beach hunter so handy whilst also giving the option to make it a free detector from finds.

I always though park hunting definitely helped keep me detecting ready when the weather time or distance stopped me from getting out gold detecting. Added bonus is figuring out what they are capable of.

 

[XLOOX]

Not stupid, just depends on the ground & target combo whether a VLF or a PI is a better choice.

As Muk says there will be some ground that is so mineralised that you simply cant use a VLF.

But equally there is some ground around old workings that is so trashy that in practice you couldnt use a PI

Personally there is nothing I hated more than driving 1000km to a mouth watering spot only to find my detector wasnt up to it ( looking at you ADS Deepseeker & TDI SL...).

With my Kruzer & SDC combo that is a thing of the past.

I guess if there was a really trashy & really highly mineralised area then I would be screwed but so would everyone else.

A second hand GP and your Nox would cover all bases and in total wouldnt set you back $3k.

But in the end its your hobby, only you can decide how much is worth spending on it.

 

[UnderEmployedGeo]

Cheers for the replies. I think the 800 will keep me happy given I kinda go out there "to be out there", not as a determined search for gold. That may change again... I wasn't enjoying my QED before.... Maybe one day I'll take out the mortgage on a Minelab PI