Pulse induction detector alternatives to Minelab GPX series?

[GreyGhost]

I've been detecting for about a year and a half in Arizona with my Gold Bug Pro. I've been hitting some areas sometimes weekly that are known gold producers (Las Guijas, Greaterville) and still haven't had any luck finding nuggets.
Recently I upgraded to the 10" DD coil for my GBP to try and get a little more depth out of my detector. The areas I detect have alluvial gold and the miners that have worked these areas dug down into the gravel and bedrock for the nuggets. The gold out here is deep and naturally the areas that are gold bearing are extremely mineralized; white floater quartz everywhere, dark red soil and hot rocks at every step. I've been detecting an area recently with magnetite boulders the size of basketballs! Swing the GBP near one of those and the thing goes nuts.
I don't feel I'm getting enough depth out of my VLF detector or enough ground balancing or discrimination for these extremely mineralized areas. My chances of finding surface nuggets within the first few inches of over burden that my GBP can sniff through just doesn't seem to be cutting it. My GBP feels like a toy out here, these areas have already been hit for years by other guys with VLF detectors so anything within the first few inches of ground is long gone.
So I'd like to upgrade to a pulse induction detector. However a $4-5$k Minelab GPX just isn't in my budget. Are there any viable PI alternatives to the GPX series that might be a little less expensive?
Thanks

 

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[H-2 CHARLIE]

Atx at $2,200 or the new minelab in the next few mos. sdc F-7 WHICH IT SHOULD BE BETWEENN 2-3 K... THESE ARE MY CHOICES FOR A MID LEVEL GOLD MACHINE

 

[Rick K]

There's also the Whites TDI and TDI SL. I have a TDI and an ATX. They have roughly comparable performance - although they are quite different machines. The ATX is a more sophisticated design and is waterproof but it weighs a TON! The TDI is more adjustable, takes a wide range of TDI specific coils and any coils for the Minelab PI's also fit. To top it off, used TDI'S are available for well under $1000.

I also have a ML SD-2100. It seems a bit deeper than either the TDI or ATX, but it is burdened with a warbly threshold which can be tiring to listen to. These are available used for around $1000 as well.

 

[huntsman53]

I am wondering if a White's Surf PI could be sent back to the Factory to get a power boost and possibly a larger coil. If that could be done, I believe that these Underwater metal detectors that also work great on dry land, would perform just about as well as any of the $4,000 to $5,000 Minelabs.


Frank

 

[Rick K]

The problem with the surf type PI detectors is,that they have no way to compensate for ground mineralization. They are useless in any kind of mineralization. I have one of those also!

the only exception was a machine designed by Eric Foster called a Goldquest SS. it used DD coils,and,a,trick Self Adjusting Threshold to allow terrestrial use.

 

[AzViper]

I've been detecting for about a year and a half in Arizona with my Gold Bug Pro. I've been hitting some areas sometimes weekly that are known gold producers (Las Guijas, Greaterville) and still haven't had any luck finding nuggets.
Recently I upgraded to the 10" DD coil for my GBP to try and get a little more depth out of my detector. The areas I detect have alluvial gold and the miners that have worked these areas dug down into the gravel and bedrock for the nuggets. The gold out here is deep and naturally the areas that are gold bearing are extremely mineralized; white floater quartz everywhere, dark red soil and hot rocks at every step. I've been detecting an area recently with magnetite boulders the size of basketballs! Swing the GBP near one of those and the thing goes nuts.
I don't feel I'm getting enough depth out of my VLF detector or enough ground balancing or discrimination for these extremely mineralized areas. My chances of finding surface nuggets within the first few inches of over burden that my GBP can sniff through just doesn't seem to be cutting it. My GBP feels like a toy out here, these areas have already been hit for years by other guys with VLF detectors so anything within the first few inches of ground is long gone.
So I'd like to upgrade to a pulse induction detector. However a $4-5$k Minelab GPX just isn't in my budget. Are there any viable PI alternatives to the GPX series that might be a little less expensive?
Thanks

Hi Chris,

I was out in Greaterville this morning for a good 4 hours making a delivery of water and buckets to help out a friend. I also made my way over to mining partner who just bought the ATX who was working an area in Greaterville. There are lots of videos on YouTube of the ATX. As mention its not a lightweight such as the 2.5 pound GBP as it tips the scales around 6.5 pounds, but it will go much deeper. Your right the Greaterville area has been hit hard with the VLF's but there are areas where nobody will go into because the bushes will rip the clothing from your body, but if your game for it I have been told the gold is waiting for someone to swing over it.

 

[2cmorau]

I favor the TDI, short learning curve
Poison Oak keeps me out of a lot of areas

 

[63bkpkr]

Once upon a long time ago a very sweet lady asked if I could remove/cut down some of the blackberry bushes on her property, she had about 2 acres of large/tall all grown together blackberry bushes. The prospect was ugly so I made a few test runs on this stuff to find that all the typical plastic blades were useless. I purchased a 7.25" 18 tooth carbide circular saw blade and returned to her place to manufacture a spacer from a washer I'd purchased for the job. The hole in the washer would JUST go over the mounting shaft of her gas powered weed whacker. I mounted the washer on a bolt, ran a second washer up to the first, added a lock washer and spun on a nut and tightened the assembly good and tight. Next I put the open end of the bolt into her lathe. (Note here: she did not know she owned a lathe, she only had a 3/8" B&D driver drill and that is what I used)


I clamped the Drill Motor to a bench top, and with the bolt held snugly in the drill chuck I turned the unit on and went to work on the washer with a good but not really aggressive file. Every now and then I would stop and measure the outside diameter of the washer with a caliper, the measurement would tell me if I'd gone too far or had more to go. The closer I got the the dimension of the Inside Diameter of the hole in the saw blade I would become more and more gentle with my filing strokes. I reached the point where the washer was just small enough to be able to tap it into the bore hole of the blade.


I installed the blade onto the weed whacker, making certain the blade was installed in the "cutting direction" of the whacker, on top of the blade I added a large diameter "Fender Washer" and then the whacker nut. The fender washer does two things - first it holds the spacer in place and second it holds the blade in place -- the spacer is there to center the blade to the weed whacker shaft. I made certain the whacker nut was tight and tested it frequently during the work and it was always tight.


I cleared out about an acre of blackberry bushes with this unit and went through two blades due to contact with rocks in the ground. After going through the first 18 tooth blade I went up to higher quantity toothed blades with the result that the more teeth I had the faster it cut. Understand here that the blackberry stalks have a lot of water in them so they cut easier than dried actual wood so bringing the blade into contact with actual trees or dried bushes or dead trees and etc. one must be careful to not be to aggressive or the blade will bounce off of the object to be cut up. I did cut down some 2" diameter trees with this unit but I did it slowly and carefully.


I have all my fingers, toes, skin and bone after the work that I had before the work so I know this works BUT if it is not treated carefully some serious damage or death could result from using this tool.


So gold versus bad weeds/bushes/scratchy-pokey-mean bushes and such no problem it just takes time, gasoline, a couple of blades, extra shaft nuts, spacers, washers and some determination and it all works. With the long tentacles of the blackberry bushes I found that cutting them into 12" long pieces was the best way to deal with them. A 10' to 12' piece of blackberry 'vine' will grab everything it touches including the person that is holding it so I cut them into the one foot lengths so they could be easily racked and wagon-ed away.


Cut a little, rake a little, detect a little and repeat. Best of success to you should you try this out!...................63bkpkr


A last note here: Be Certain to ONLY use this method with the guard still on the weed whacker! Always use the guard as if that blade comes off it could easily cut a leg off! Gold is not worth damage to the self, be careful with this tool!

 

[Hard Prospector]

TDI SL with the 7.5" DF and 7.5" Mono Aussi coils and you've got all your bases covered in the gold fields. Keep in mind the GPX series stands alone but of all the mid range PIs available, I feel this is still the best option especially for around $1600.00 bucks.

 

[GreyGhost]

Atx at $2,200 or the new minelab in the next few mos. sdc F-7 WHICH IT SHOULD BE BETWEENN 2-3 K... THESE ARE MY CHOICES FOR A MID LEVEL GOLD MACHINE

I wasn't aware of this new Minelabs coming out, will have to look into it.

Hi Chris, I was out in Greaterville this morning for a good 4 hours making a delivery of water and buckets to help out a friend. I also made my way over to mining partner who just bought the ATX who was working an area in Greaterville. There are lots of videos on YouTube of the ATX. As mention its not a lightweight such as the 2.5 pound GBP as it tips the scales around 6.5 pounds, but it will go much deeper. Your right the Greaterville area has been hit hard with the VLF's but there are areas where nobody will go into because the bushes will rip the clothing from your body, but if your game for it I have been told the gold is waiting for someone to swing over it.

Yeah I'll definitely keep trying Greaterville. It's only about an hour from my house to get to the area you showed my on Google Earth so its pretty convenient.

Once upon a long time ago a very sweet lady asked if I could remove/cut down some of the blackberry bushes on her property.....

Wow great post!

 

[huntsman53]

The problem with the surf type PI detectors is,that they have no way to compensate for ground mineralization. They are useless in any kind of mineralization. I have one of those also!

the only exception was a machine designed by Eric Foster called a Goldquest SS. it used DD coils,and,a,trick Self Adjusting Threshold to allow terrestrial use.

I thought that the Surf type PI detectors were preset or self-adjusting for mineralization as they are built for underwater use and saltwater is highly mineralized.


Frank

 

[Rick K]

Ground balance in metal detectors either VLF detectors or pulse induction detectors is required because of something which is often called magnetic viscosity which exists in many types of soil. This is most often due to the ferrous content of the minerals in the soil.

Beach sand whether dry or wet typically does not have a lot of this mineralization. Detectors like the Surf PI are designed to not see salt water as a target. They also will not see typical beach sand as a target. When I take my WHITES DF PI Out on my property here in Arizona and lower the coil to the ground, it sounds off continuously. This is because it sees the mineralized soil as a target. There is no way to compensate for that or adjust it away.

PI detectors like the TDI, ATX, and the Minelab SD and GPX series have additional circuitry which takes two separate samples at different time delays and uses them to "subtract" the ground signal.

 

[Steve Herschbach]

Surf type PI detectors do not ground balance at all. They simply rely on the inherent PI ability to ignore salt water and evenly mineralized ground if the pulse delay is sufficiently high. By nature due to their design goal of ignoring salt water they are unable to pick up small gold a properly designed prospecting PI will find and they are unable to compensate for extreme ground and hot rock conditions. Surf detectors can be used to find gold nuggets as long as the ground is evenly and not too intensely mineralized.

Garrett Infinium and ATX plus Whites TDI versions are alternatives. The TDI SL is the most ergonomic and affordable; the Garrett ATX the closest to the GPX in performance.

 

[GreyGhost]

I also have a ML SD-2100. It seems a bit deeper than either the TDI or ATX, but it is burdened with a warbly threshold which can be tiring to listen to. These are available used for around $1000 as well.

These can be had for a good price online. Not the D or E models or 2200 models but just the standard 2100. Besides the threshold issue anyone else have opinions about this detector?
Trying to get into the PI game and I know the Minelab name is legendary. Haven't started researching the White's or Garrett models mentioned yet.

 

[H-2 CHARLIE]

Ground balance in metal detectors either VLF detectors or pulse induction detectors is required because of something which is often called magnetic viscosity which exists in many types of soil. This is most often due to the ferrous content of the minerals in the soil.

Beach sand whether dry or wet typically does not have a lot of this mineralization. Detectors like the Surf PI are designed to not see salt water as a target. They also will not see typical beach sand as a target. When I take my WHITES DF PI Out on my property here in Arizona and lower the coil to the ground, it sounds off continuously. This is because it sees the mineralized soil as a target. There is no way to compensate for that or adjust it away.

PI detectors like the TDI, ATX, and the Minelab SD and GPX series have additional circuitry which takes two separate samples at different time delays and uses them to "subtract" the ground signal.

steve any news on minelab newest F-7 ? anything at all

 

[Steve Herschbach]

There is no F-7 Minelab. You must be thinking of the SDC 2300. Electronics are still being tweaked. My expectation has been by middle of this year, maybe sooner, but I am not holding my breath.

 

[Steve Herschbach]

Personally if I was looking for a used Minelab I would be after a GP3000 or GP3500. Should be able to get one used for about same price as Garrett ATX new. GP3500 was the pinnacle of the analog models before the switch was made to digital with GPX4000.

 

[GreyGhost]

Really liking the looks of that SDC 2300! Should maybe just save my pennies till it comes out.
Hope it's a "serious" detector with interchangeable coils and not something expensive with a gimmicky folding design.

 

[woof!]

Steve is correct, beach PI's are a whole different animal from gold prospecting PI's. Been there and done that with PI's before I realized the potential PI had for gold prospecting.

 

[2cmorau]

Now i am really bummed you moved to Texas, i have an area of poison oak that needs just the work you described,LOL but i have a solution, ( don’t worry it’s all natural spray) it just takes a couple of seasons to make the PO disappear