By Steve Herschbach
For the newbies.
There is this idea that detectors are defined by x depth on some items. I’m coming to discover the difficulty involved in explaining to people that the detector does not directly explain the true situation. The mix of gold type, ground mineralization, EMI, hot rocks, trash targets, terrain issues (steep ground, dense brush or boulders, wet or dry), and more decide which machine is best. Context is everything, but few people ever discuss it when reviewing detectors. The assumption is what works well, works well everywhere. No. The difference can be as stark as a $7000 detector being best in one place, and a $900 detector being a better choice someplace else.
If you want the best advice possible, find a genuine gold prospector, one who has years of experience in the same locations you want to hunt, and get their thoughts. Ignore the majority of the people posting anything on the subject, because frankly many have no idea what they are talking about. In gold prospecting, pay attention to those investing considerable time and money, with an expectation of profit. They have to be operating in situations that match up with your mix of conditions. They are serious enough to have considered and tried all viable options. I’ll say this also. Some people who have been doing this five years are better at it than others who have been in it a long time. So it’s not about length of time either. Some people are just better at this stuff.
Now, just a warning, some of us prospectors are nuts, and you can find people who think crazy stuff finds gold. But in general, I think this is good advice to help cut though the clutter. Quantity of opinions is not as important as the quality of those opinions. If a prospector measures his gold in pounds, that’s a pretty good sign.
Now I'm not saying other opinions are not valid. Not at all. This is just a strategy for weeding it down some. There are people you can follow over time that you can tell you want to listen to, and they may be pretty low key, not showing off gold. And a person may be a real class act, but simply not have much good gold nearby, that limits what they can find.
Long story short, the shortest route to success as a newbie would be to hook up with the right person in the field. Probably save ten years of messing around. The easy route here is to meet up with a couple dealers that offer classes. There is a huge divide between the people who are good at this, and the rest. If you can ever hook up with a genuine prospector in the field, expending the time and dollars would be the smartest thing most new people can do. Gerry McMullen and Rob Allison are fine choices. I'm sure there are others, but I will vouch personally for those two. I don't know of anyone else running classes these days. Bill Southern does some free outings, where you can no doubt bend an ear or two. Chris Gholson seems pretty invisible these days.
Getting this training before you buy your new detector has big advantages. It could keep you from buying the wrong machine.... or even make you decide to save your money entirely. Nugget detecting is not for everyone.
Right, this one is a true classic, the counterfeiters in China have outdone themselves on this one.
It's a cross breed of a GPZ, GPX, Digital Photo Frame, Mp3 Player, Movie Player, Ebook Reader and all metal gold prospecting metal detector all in one. You name it, it can do it.
It comes with various colour schemes, one to suit every taste. The shaft looks like a cross between the GPZ and GPX. The Arm cuff looks like a GPX arm cuff somehow they've mounted on a GPZ body using wing nuts.
The battery clips look like a decoration.
The buttons are fancy, I wonder what identify mode is, maybe they've done a ZVT detector with Target ID's! My dream has come true. A calendar would be very handy while out in the field, don't want to miss those appointments.
And without further ado, a video of this bad boy in action!!!!!
High Precision Underground Gold Scanner Machine ZVT Technology For Archaeology
Single package size:85X40X15 cm
Single gross weight:4.0 kg
Package Type:standard package
Application: Gold Prospecting (Waterproof coil to 3ft)
Frequency/Transmission: Zero Voltage Transmission (ZVT)
Coil (standard): 14" x 13" Super D Configuration with skidplate (waterproof to 3 ft)
Audio Output: 1/4" non waterproof socket, Wi Stream wireless signal transmission
Headphones Supplied: KOSS UR 30 100 ohm with 6.3 mm plug (1/4 inch) (non waterproof)
Visual Display: Full colour LCD (320 x 240 pixels)
USB Connectivity: USB interface for XChange 2 PC software
Detect Modes: Gold Mode (High Yield, General, Extra Deep) Ground Type (Normal, Difficult, Severe)
Discrimination: All Metal
Audio tone: 1 100
Ground Balance: Auto and Manual (Quick Trak trigger button)
Sensitivity Adjust: Level (1 20)
Tune / Noise Cancel: Auto and Manual (256 channels)
Threshold: Level (1 50) Pitch (1 100)
Target Volume Adjust: Range (1 20) Limit (1 20)
Battery: LiIon Rechargeable Pack (7.2V DC, 72Wh)
Low battery alert: Yes
High-brightness LED panel can generally displays the detected metal type according to the signal strength.
The all-metal detection mode is suitable for searching metal objects on the ground, and can be a simple recognition of metals
In addition to LED panel display, it can distinguish metal type by tones
9.5-inch disk waterproof probe that can detect in the shallow water.
Equipped with an external headphone jack ,connected to a single-channel headphones (headset-owned), easy to use; built-in high-capacity rechargeable battery Worked continuously for more than ten hours when full of power.
I assume I don't have to warn anybody here not to buy one? 🙂
Would like some help please on a specific coil for my TDI Pro,i have the option of buying this brand new Coiltek 6'' Mono coil which was of course specifically designed for the GPX range of detector,the GPX Mono coils do work very well on my TDI Pro as i own and use most of them on the TDI.
Has anyone specifically used this small 6'' Mono coil i am looking at using it most of the time because i am using smaller coils more and more due to the problems that i am hving with a broken wrist that i had from a bike accident decades ago,does anyone have any thoughts on this combination please.
I am chasing some advice, I recently swapped my QED PI detector for a Garrett AT Gold. I basically never used my QED and it was gathering dust and wasting cupboard space which with my growing collection is becoming an issue, I've never gotten rid of a detector before, I even have my first detector from when I was about 9 years old but I decided the QED had to go. I offered to give it to a friend but after trying it out in my backyard he decided detecting isn't for him as it was too complicated 🙂. An opportunity came up to swap it for an AT Gold to a guy in Australia who offered to swap his AT Gold plus some cash for a QED, I just took the direct swap with no cash involved to keep it simple so I jumped on it and sent the QED on it's merry way on an international flight the next day.
So now I have an AT Gold, I've messed around with it and the gold performance is not near the VLF detectors I prefer to use for gold more on par with my other 19kHZ detectors from other brands that also spend their life in the cupboard and nowhere near the performance of the higher frequency VLF's that I do use so I figured I'd get a bigger coil for it for coin hunting, not because I'm expecting it to compete or compare to my other coin detectors but just to give it another purpose as I'm unlikely to use it for prospecting, although maybe the odd creek trip being waterproof might be in it's future.
It's in tidy condition, the owner was a GPX 4500 guy and in the land of OZ with high mineralisation so the AT Gold was a cupboard decoration for him too. He sent the Garrett headphones for it too but I have a phobia of headphones so they're stashed away now never to be seen again.
So, what should I do for coil options for it? The Garrett NZ dealer only has the coil I've already got for it in stock and the 9" x 12" PROformance Concentric Search coil, I am in mild soils so perhaps this concentric would serve me well for coins?
I prefer aftermarket coils in general and especially in comparison to standard Garrett coils that I've got with my Ace 350, 300i and now the AT Gold, so would I be better off getting a Detech Ultimate, Nel Superfly or Tornado for it? I have both the Ultimate and Tornado for other detectors and really like them and I love that I even have the option of getting these coils with the Garrett as it is one of the things I absolutely despise about the other brand that doesn't allow aftermarket coils.
I've tested the stock coil on it and the target ID's are pretty poor on my usual coin digs, my Ace 300i with Nel Tornado is giving me deadly accurate Target IDs on deep NZ coins at 6+ inches in depth and the AT Gold with stock 5x8' is all over the place on the exact same targets, very unreliable ID's and won't even detect a 8" coin that the Ace 300i hits on with ease with the Tornado. Yes I know, big coil, little coil.... this is what I want to improve.
On Ebay there are a brand of coil I've never heard of available for the At Gold, Magic Coils, made in Russia and they look quite good, Youtube personalities like The Hunter GT have left them very positive reviews but I can't find too much info on them, I'm always willing to try new things though, you never know when you'll discover something special others aren't willing to try.
Here is one for sale for the AT Gold https://www.ebay.com.au/itm/292834716248?hash=item442e4f2a58:g:ijgAAOSwkB5b~EMv
So what's my best option from people using one of these higher end Garrett VLF's, Nel? Detech? Magc? or the good old trusty stock coils? if so which one? As at the moment for coins my Ace 300i is flogging it for target ID stability and depth using the Nel Tornado vs the 5x8" Garrett DD on the AT Gold, even on shallow coins the ID's are more stable on the Ace.
Also, is it worth getting a Nel Snake for it to get a decent little gold coil? I have one for my GBP's and it works well, again no match for the higher frequency detectors I prefer to use, has anyone used a Snake on an AT Gold? I don't expect it to compete with higher frequency detectors but even if it handled hot rocks better or anything it might be an option worth considering.
By Steve Herschbach
My first comment regarding discrimination with a ground balancing PI like the TDI and others is that people may be expecting things of the TDI it cannot deliver, and may be better off with a good discriminating VLF detector. If your priority is discrimination, no PI will discriminate like a VLF.
There are two ways to tune the TDI. The first and preferred option is to tune the detector for the best depth. On low mineral beaches ground balance "off" usually give the best performance and you generally have to dig all targets. The sensitivity control and pulse delay are set to the desired level of quiet operation. You have to adjust those settings for your conditions. Forcing it by using settings other people use is fruitless. Salt conditions do vary as does mineralization and electrical interference, and the machines themselves vary by a small amount.
I notice many people think lower settings will cause lost depth and therefore insist on higher settings, and then complain the machine is unstable. It simply is what it is. Adjust the machine for the conditions. If it does not perform to your satisfaction, use a different detector. You can't make a detector do what it does not want to do.
As ground mineralization increases on some beaches, there is a point where using the ground balance “on” gives you more depth. Only with experiments can a person determine which setting gives more depth on your beach - ground balance “on” or ground balance “off”.
If you use the ground balance, it BY ACCIDENT creates two audio classes of targets, those above the ground balance setting and those below the ground balance setting. These give either a low tone or a high tone. The resulting two classes of targets have only a little to do with what they are made of, but are based instead on the rate at which eddy currents decay in the target after the transmit pulse shuts off. Size has as much to do with the audio results as composition, just like on a VLF. The pulse delay sets the minimum level for this eddy current cut off or rejection. See Understanding the PI Metal Detector by Reg Sniff.
With ground balance “on” you would normally, just like with ground balance “off”, adjust the sensitivity and pulse delay for whatever level produces quiet operation. I usually just put the coil underwater and pump it in the water, and first try lower sensitivity. If that does not remove noise I raise the pulse delay a little and try again. In general I am trying to keep the pulse delay as low as possible and sensitivity as high as possible. Eventually through trial and error I find a combination of sensitivity and pulse delay that eliminates audio results when pumping the coil in saltwater.
The ground balance setting is determined by whatever setting gives no audio results when moving the coil up and down over the beach or the bottom when underwater. If basalt cobbles are present they may also need to be included in the ground balance tuning procedure. In extreme cases you may have to lower the sensitivity and pulse delay even more to get a proper quiet ground balance.
Again, once you have tuned everything for best performance, you will have a pulse delay setting and ground balance setting that ACCIDENTALLY creates two classes of targets. The only way to see the result is to test various targets. In the U.S. our coins are much more conductive than many European coins and retain eddy currents better, and therefore generally give a low tone while most jewelry will give a high tone. Large ferrous will give a low tone and small ferrous a high tone. Very large rings may give a low tone as will most silver rings. In Europe and other places the tones may vary from what we see with U.S. coins.
After experimenting to find out what items give what tones, you have a simple decision. You can dig one tone only, or you can dig the other tone only, or you can dig all targets. The results will be what you have determined by your experiments and if digging only one tone or the other loses items you do not want to lose then you must dig all items. If that is not acceptable, your should be using a VLF detector instead.
Now, if you are willing to give up some depth, you can try to purposefully misadjust the ground balance control to move the tone division point. Doing so may switch some items from one tone to the other for a better result as regards discrimination. This however puts the detector out of proper ground balance. In mild ground you can do this easily but in highly mineralized ground the machine will now signal when moved over the beach or the bottom or past hot rocks. The depth is lost as you compensate for this by again reducing the sensitivity or increasing the pulse delay. Again it all is a matter of experimentation. If a desired item that is giving a "wrong" tone can be made to give the opposite tone by misadjusting the ground balance you may benefit from this in milder ground. It may be that the lost depth or audio side effects from being out of ground balance are not be worth it. You have to decide.
To sum up, VLF detectors offer the best discrimination but may not get enough depth on mineralized beaches. A PI detector can get more depth, but any discrimination is an accidental byproduct of the ground balance system employed and will not separate targets like a VLF. In general you dig everything with a PI but in some cases you can derive benefits by digging some tones and not others, but you will without a doubt miss some class of good targets by doing this. That is just the way it is.
The first ground balancing PI (GBPI) I used for beach detecting was the Garrett Infinium. Next was the TDI and then Garrett ATX. All three have similar tone results, but the TDI has the additional benefit of allowing you to manually set the tone break point via the ground balance setting. I have also used similar tonal separation using Minelab GBPI detectors. I go into more in-depth detail on another post referencing the new Fisher Impulse AQ where I reference all my notes on all these detectors so I am going to link there for further study. The Impulse is basically a refined version of what the TDI is doing, with the ground balance control used first and foremost as a discrimination control, and as with the TDI there will be performance trades depending on the settings employed. Understanding one will help you understand the other.
This is a very complex subject for those wanting a simple VLF type discrimination system in a PI detector. They are however two different things, and you have to read and think quite a bit about how a PI detector actually works to get your head around all this. Or at a minimum do lots of experimenting and learn by observation. I have tried my best to explain things, but there is no magic tuning or answers I can provide that will make these machines do what people seem to want them to do - act like a VLF. They are not. If they do not discriminate the way you want I have no settings that will make it happen other than what I have tried to explain already. This is kind of a summary and along with all the other posts is really about all I can offer or have to say on the subject. I hope it helps!
Fisher Impulse AQ Discrimination Explanation
Where Will The Holes Be In The Fisher Impulse System
White's TDI SL Owners Manual
White's TDI Beachhunter Owners Manual
White's TDI Pro Owners Guide
Steve's White's TDI Review
I have a question please help me
I found a site containing gold nuggets, and the problem is that it is next to a microwave or radar tower
The detector is very noisy, as if the whole earth is aluminum cans with GPX 5000 and Double D coils and Z7000 no pilot, and our choice was to use the gold monster
What is the solution? Is there a detector that provides better depth than the monster and can work in these conditions
I hope who found an actual solution Heuristic
Thank you all I thank Good forum