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Steve Herschbach

Under 4 Pound, Under $2000 Gbpi Challenge

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OK, final note. Just in case novices or newcomers to the forum are reading all this and taking it as a full blown endorsement of the White's TDI SL. Far from it.

I have rigged the game here by placing an reasonable (in my opinion) but artificial set of limits in place. The reality is that many detector users really only care about one thing - pure power. If you are a gold prospector who finds substantial amounts of gold (money) while metal detecting, all else is secondary. Cost is less important because your tools are paying for themselves. Higher cost just means more hours before reaching the breakeven point. For some people price is just not an issue. And ergonomics? I once jokingly told a Minelab engineer he could put spikes in the armrest that made me bleed every minute I was detecting, and if it meant I found a lot more gold, I would do it! Exaggeration perhaps but not that far off the mark either.

Given that reality the fact is there just is not a huge demand for machines near last place. The TDI SL shines here because of the parameters I have set up, but it only shines as far as weight and cost. Being a 2 on my "Minelab Scale" means there are a lot of detectors out there with far better performance, especially as not all of them are on that list, like the ATX and SDC 2300. The TDI SL is pretty low on the totem pole.

The reality I faced when using the TDI SL was that in low mineral ground it truly is not any better than any good VLF run in all metal mode. In fact given that most VLF detectors will hit smaller gold, and offer some form of ferrous discrimination, the TDI SL is a step backwards. White's own GMT and MXT models both are more compelling choices for most people working in lower mineral environments. You have to get into ground so mineralized or with hot rocks so bad that the GMT or MXT are really struggling before you really see the benefit of the TDI SL. Having a hard time ground balancing, machine overloads unless sensitivity backed way, way down? Hot rocks nearly every swing? Break out the TDI SL and those issues just go away.

This is why many people who don't get around much or have not experienced those types of ground conditions are truly puzzled by the TDI SL. Their VLF pretty much kicks its posterior, so they just don't get it, and even go so far as to think the machine is a rip off. A lot of the ground I have encountered in Northern Nevada, for instance, is mild enough that I believe I would be better off running a GMT than a TDI SL, especially given the prevalence of small and porous type gold. Bottom line is that for the TDI SL to look good compared to a decent VLF, you need some really bad ground.

So before you go thinking "aha, Steve says I should buy a TDI SL" think again. What I am really trying to do here is get more and better machines into this under 4 lb, under $2K region. The TDI SL simply wins by default.

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Novices and newcomers and extreme fans may want one just because you put it on the list...it is just human nature to skip over the explanations and facts to get to a conclusion...

No one can say you have not given clear explanations of your desires and opinions...kudos!

fred

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Steve I'm not that up on the workings of the current or past Minelabs. Is it the weight of the battery, electronics or search coil that causes a PI to weigh over 4lbs or the combination of all three? I know with the TDI the weight of the battery and 12" search coil make the detector on the heavy side, but if the smaller coils are used the detector is manageable for all day use. If it is the battery that causes a PI to be on the heavy side, is there technology out there to power a PI today that would make it lighter?

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It is just everything - it all adds up. Certainly newer modern battery systems will go a long way to making detectors lighter. There are still quite a few detectors using eight AA batteries. The TDI SL is under 4 lbs but honestly looking at the weights below just getting under 5 lbs is doing good. Unlike all the others the TDI SL could actually add a little weight and still look very good.

Here is a list of nugget detectors sorted by weight with my own somewhat arbitrary categories. Weight is not everything as balance is also very important, as is the handle design. Obviously the ability to hip mount counts for a lot. Properly designed bungee systems can render even heavy detectors weightless on the arm.

VERY LIGHT

Fisher Gold Bug / Gold Bug Pro  - 2.5 lbs. with 5" coil and one 9v battery (2.7 lbs with 10" elliptical coil)

Fisher Gold Bug 2 - 2.9 lbs. with two 9v batteries (may be hip mounted)

Minelab X-Terra 705 Gold - 2.9 lbs. with four AA batteries

Garrett AT Gold - 3.0 lbs. with four AA batteries

Makro Gold Racer - 3.0 lbs. with four AA batteries

LIGHT

Minelab Gold Monster 1000 - 3.5 lbs with eight AA batteries

Tesoro Lobo Super TRAQ - 3.5 lbs. with eight AA batteries (may be hip mounted)

White's TDI SL (GBPI) - 3.5 lbs. with eight AA batteries (3.0 lbs. with 7.5" coil)

White’s GMT - 3.9 lbs. with eight AA batteries

MEDIUM

Nokta FORS Gold / FORS Gold+ - 4.3 lbs. with four AA batteries

White’s MXT - 4.3 lbs. with eight AA batteries

HEAVY

Minelab Eureka Gold - 5.3 lbs. including rechargeable battery pack or optional eight AA batteries (may be hip mounted)

Minelab GPX 5000 (GBPI) - The GPX weighs 5.3 lbs. not including the harness mounted proprietary rechargeable battery, which weighs another 1.7 lbs (7 pounds total). Detector weight normally supported by bungee.

Garrett Infinium LS (GBPI) - 5.6 lbs. including rechargeable battery pack or eight AA batteries (may be hip mounted)

White's TDI and TDI Pro (GBPI) - 5.6 lbs. including proprietary rechargeable battery (may be hip mounted)

Minelab SDC 2300 (GBPI) - 5.7 lbs. including four C batteries

VERY HEAVY

Garrett ATX (GBPI) - 6.9 lbs. including eight AA batteries

Minelab GPZ 7000 - 7.2 lbs. with standard rechargeable battery

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Great thread and couldn't agree more Steve. 

If anyone can do it, it is Minelab. Why? They already have the technology to place themselves anywhere on your number list. They also have a big Engineering team. Pretty much throw the Gold monster and the SDC into a pot, stir it around and pull out some sort of hybrid. 

Yes agree with your comment about the TDI, in mild ground any decent VLF will ping small gold better, and will even keep up with it depth wise when bigger coils and lower frequencies are used. That is the beauty of the GPX series in particular, optional timings and various adjustments like Rx Gain, Audio Type and optional Timings means that they can be optimised regardless of ground type. With a small mono coil they are so sensitive they will pick up smaller gold then a lot of VLF's except for dedicated very high freq machines. 

You forgot to add the Gold Racer into your Very Light section :rolleyes: It is also the best balanced machine due to having the battery compartment under the armrest.  

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Yeah Nenad, it was late so I figured on finishing up today but welcome the reminder. I added the Gold Racer at 3.0 lbs and also the Gold Monster at 3.5 lbs with batteries (the specs quote it without).

Manufacturers - none of us swing detectors without batteries. I want to know what's hanging on my arm. State weights with batteries. And some catalog weights are understated. Nearly all Nokta detectors weigh more than stated in their literature. All weights quoted on my website pages are normally derived from my actually weighing units with batteries included on my digital postal scales. The Nokta FORS Gold units, for instance, are catalog quoted at 3.9 lbs including batteries but weigh 4.3 lbs with batteries on my postal scales. Its not just Nokta - I have caught others out on this before.

The TDI SL as I note above is dramatically lighter than other GBPI options, so much so White's could add nearly a half pound of battery mass and still have a detector weighing under 4 lbs. Really no excuse not to go to a larger, more powerful battery. The other guys just getting under 5 lbs with batteries included would be a real accomplishment.

I agree Nenad. How many years have to go by with Minelab watching people strap external batteries and speakers on GPX detectors before we can just get a stripped down GPX with built in speaker and integrated rechargeable or drop in battery? I don't mind changing batteries mid-day if that is what it takes to get decent ergonomics. Here is a picture from Minelabs own Pro-Sonic video showing wireless audio being adapted to a GPX 5000 that has a Minelab half-size battery strapped to the side. I understand Minelab not wanting to undercut existing model sales, so if it has to be a limited control set locked into just Normal or Fine Gold timings, I am all for it. Better for beginners that way anyway. Or as a second unit for people who own the full blown rigs.

minelab-gpx-5000-with-integrated-battery-and -wireless-audio.jpg

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The problem with the little half battery is the battery life, i unlike you steve need a battery that lasts all day like the current GPX battery does, the little half battery although i would love to be able to stick it to the side and become "wire free" is not viable when im kilometres from the car prospecting on the side of a hill somewhere... i tend to walk around quite a lot and dont carry spares with me ....What i need is a little battery that has a big batteries "life"! ahh in an ideal world :)

 

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I have the White's SPP it may work great in some ground that a VLF can't go but it's under powered and eats AA batteries like they grow on trees.

Right now I'm just going to live with what I got and that's a Gold Monster 1000. I find a place I can't hunt I'll just move on.

If I'm finding gold the pain of the weight of the detector don't hunt so bad.

GPZ 7000 Where are you ?

It's so many detectors out there and i don't want to buy them all to have what I want. So I'll just live with less and be happy.

you can now call me less happy Chuck

Chuck 

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On 6/13/2017 at 11:53 AM, Aussieau said:

i unlike you steve need a battery that lasts all day

I need full day operation also. My attitude is that if a detector needs a battery swap during my lunch break to stay light then so be it. If running time on one battery is paramount then we already have detectors that do that anyway so no issue really. I agree though and that all day operation on a charge is preferable and should be no problem with modern Lithium Ion batteries.

Chuck, I personally would take a GM1000 over the TDI as a general nugget hunter. The problem as I have noted is that unless the mineralization is pretty severe then I think a good VLF is a better choice than the TDI SL. The GM1000 running in full auto is as close to a PI as you can get in a VLF, and even easier to operate. The main thing is it will bang hard on smaller bread and butter gold the TDI can't touch. The TDI does a decent job as a PI in high mineral ground but is poor in low mineral ground compared to a good VLF.

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      The ultimate constraint on the kind of gold a PI detector can find has never been pulse delay. There are commercial PI detectors designed to find pin-sized targets. For gold prospecting the constraint is always the ground. If you make a detector with a 1 uS pulse delay, all it will do is light up the ground like the largest target ever found. The key is the ground balance technology employed, and how efficient it is at eliminating ground and hot rocks, plus alkali effects in some areas, while losing as few gold nuggets as possible.
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      That is how all this works folks, time constants. PI detectors know nothing about ground or gold or ferrous or non-ferrous. Conductivity is loosely involved if at all. You can accept targets and reject targets or ground based on their time constant, and for every good target there is a bad target that has an identical time constant, and vice versa. That is the reality of the technology, and getting your head around it is the key to knowing what these detectors can and cannot do. Does the Impulse AQ exhibit any detection “holes?” My answer is define first exactly what you mean when using the term, then apply that to the AQ to get your own answer.
      UNDERSTANDING THE PI METAL DETECTOR by Reg Sniff
      For anyone who wants to dispute any of the above, please provide an exact definition of what a “detection hole” is, and how it does or does not apply to the Fisher Impulse AQ.
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