Difference between VLF and PI metal detectors

Prospecting Australia

Help Support Prospecting Australia:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Rabert

Robert
Joined
Jan 10, 2013
Messages
6
Reaction score
0
Rabert here from WA.. lately I am hearing about VLF and PI metal detectors and want to ask you experienced folk whats the difference.. why choose one over the other?? Ive only used a cheapy that I bought of ebay a couple of years back but its buggered now and wouldnt even have a clue what it is.. also is VLF for coins and PI for gold?
 
Howdy Rabert, VeryLowFrequency machines have the ability to handle mineralised soil conditions and also be able to descriminate out most of the unwanted ferrous trash scattered about the place as well. Great in Ghost towns searching for coins/relics.
Pulse Induction detectors have a better ability to handle highly mineralised ground, and have a substantial depth advantage over the VLF machines. Detecting wih a PI machine is the way to go if you are serious about hunting gold nuggets, especially in WA. :D
 
Pete_The_Prospector said:
Pulse Induction detectors have a better ability to handle highly mineralised ground, and have a substantial depth advantage over the VLF machines. Detecting wih a PI machine is the way to go if you are serious about hunting gold nuggets, especially in WA. :D


Yeah good point Pete! Most detectors that work fine over east would be hopless in W A. They'ed blow your ear drums.
 
Has anyone tried the AT Gold over in WA? Based on my use here in Vic, it would surprise me if it didn't get positive results.
 
You'll only find minelab in the western goldfields. To much hot rock.
 
Ever detected in Vic Bulldog? Some of the hottest ground around is here in Vic. Not that I've detected in WA :)
 
Wedderburn in Victoria is well known for hot ground, rocks. and is reputed to be the hottest goldfield ground in world.
 
Aussie Detecting said:
Ever detected in Vic Bulldog? Some of the hottest ground around is here in Vic. Not that I've detected in WA :)

No I cant say I have. Is that an invite? :)
 
Hi Guys ' I'm new here :8

Can someone explain why a ML4500 could not signal on certain gold specimens when an older VLF ( made for gold hunting ) could ?
The 4500 had a small coil fitted & was set up correctly on the mineralized ground tested .

Thanks
OB .
 
Outback - I have tested the 4500 with a 6" mono against an Xterra70 VLF with the 10" (I think) eliptical DD. The VLF won by a margin and gave a definite advantage on the threashold - a very faint 'woof' on very small (wheat sized) pieces. I used headphones with the VLF and a speaker with the 4500 - that may be a clue. Some of our more technical friends may have the answer.
 
loamer said:
Outback - I have tested the 4500 with a 6" mono against an Xterra70 VLF with the 10" (I think) eliptical DD. The VLF won by a margin and gave a definite advantage on the threashold - a very faint 'woof' on very small (wheat sized) pieces. I used headphones with the VLF and a speaker with the 4500 - that may be a clue. Some of our more technical friends may have the answer.

Thanks Loamer , had headphones on both , the gold was easy seen on the specimens that the 4500 just did not give any signal ?
Made me feel a bit uneasy , must be some kind of anomaly :eek:
 
what size and type of coil on the 4500? Don't feel uneasy. Its horses for courses. The VLF WILL NOT find gold your 4500 can. Put a VLF up against the 4500 on a mullock heap covered in hot rocks, ironstone and red clay. The VLFs will have the sensitivity turned way down while the 4500 will just hum along as per usual. I pinged wheat sized gold with the 4500 on mullock heaps the Xterra 70 could not 'hear' due to noise and chatter. Yes, they are very good on white mullock and quartz dumps. On hot ground - they lose depth, sensitivity and are very noisy. I have seen people switch them into coin mode, to shut them up. I am not having a crack at VLFs - they are good for what they are designed for and I have posted numerous times that they have a niche on the goldfields - quiet mullock heaps and quartz dumps. I am also referring to the hot golden triangle ground - for those who have never had a crack down here on them with a VLF - be my guest.

Just a post script - there is a very good prospector who uses the alias 'BT' and used to write article in Gold, Gem and Treasure. He tested the XTerra (VLF) and came to the same conclusions as you - the VLFs did/will outperform on species.
 
A PI detector needs the gold joined together to energize it and produce a signal. VLF's can detect finely disseminated gold but this is also why they are susceptible to ground mineralization. You can test this out by trying to detect a container full of alluvial dust. I have tested this with my 5000 and it doesnt make a noise yet a whites GMT picks it up easy.
I have also tried it on some specimens in WA that contain an ounce of finely disseminated gold in a lump about the size of a tennis ball, the 5000 made no noise but the GMT detected it easy.
For this reason it is definately worthwhile to have both a PI and a VLF detector in your kit.

DD
 
Diggerdude said:
A PI detector needs the gold joined together to energize it and produce a signal. VLF's can detect finely disseminated gold but this is also why they are susceptible to ground mineralization. You can test this out by trying to detect a container full of alluvial dust. I have tested this with my 5000 and it doesnt make a noise yet a whites GMT picks it up easy.
I have also tried it on some specimens in WA that contain an ounce of finely disseminated gold in a lump about the size of a tennis ball, the 5000 made no noise but the GMT detected it easy.
For this reason it is definately worthwhile to have both a PI and a VLF detector in your kit.

DD

Amen DD. Don't sweat it outback - you will win in the long-run.
 
I saw a patch pulled out over this season and the last, out of 300+ speci's(the patch was completely speci's) only 10 pieces were detectable with the 5000....the rest were picked up with a whites GMT. Some of the pieces the 5000(and a 4500) missed contained multiple ounces in a smallish piece of quartz.
Many people would not believe the 5000 missed everything and I tried every setting possible to try and get a response from one of the speci's...not a hum beep or tweet was to be heard.
Overall over $150,000 worth of the yellow stuff was extracted from the quartz over the 2 seasons with barely a fraction of the speci's able to be heard with a modern PI machine.
So think about that when you walk around swinging....you may just be walking right over 100's of thousands worth of gold!
BTW I use a 5000 and wouldn't consider trading that in to use a whites full time....the chances of finding a patch that size of all speci's a 5000 cant hear is very remote....but if you have a spot where the gold has been peppered in the quartz then go back with a whites etc and hve a swing....you never know!
 
HI all. Been seeing all different anagrams/abbreviations relating to the type of processor used for metal detectors.

Can someone please explain what the differences are?

Thank you
 
Top