Steve Herschbach

Jim, again, are we talking about a modded unit? Or a factory stock TDI SL? What you appear to be saying is that on your detector disengaging the ground balance cuts performance across the board in air tests. What I have trying to do on this thread is illustrate why under very low mineral conditions people may want to experiment with shutting the ground balance off or reducing its aggressiveness to get better performance. There would appear to be no option for this on the unit you have, and the option to disengage ground balance may as well in itself be removed. It serves no function on your detector except to decrease performance. That being the case beach hunters would be wise to stick with the original TDI and TDI Pro because with ground balance off they are one of the best straight PI options available for beach detecting short of the Eric Foster Deepstar itself.

The technique used to ground balance a TDI so that it can ignore or cancel the ground mineral signals is done by taking multiple signal samples over a period of time. The later signals are amplified such that the signal from the ground in the later sample equals the main sample and the latter sample is subtracted from the main sample. The result is the ground signal appears to go away. What also goes away is part of the signal from many targets. If the main sample is the full signal, and the basis of results for ground balance off, and then you subtract from that by engaging the ground balance to subtract the results of a later sample - how exactly is this subtraction of part of the signal adding signal strength to targets like a quarter? Perhaps long time constant targets like a quarter have not decayed appreciately by the time the later samples are taken, and the amplification process is boosting the signal for long time constant targets over what was achieved in the original sample? Jim, the TDI SL comes with a 12V battery. Do you have a modded version of the detector? I sure am not going to dispute what you guys are saying. I admit a nickel is my standard test item and so I have not observed what happens on a quarter on the TDI SL with GB both on and off. It just highlights to me that there are multiple versions of the TDI in play and their performance characteristics are not consistent across all versions.

Well, if your machine is defective using it as an example to others of how a normal TDI SL should behave is not very helpful.

All of the three or more TDI SL detectors I have used all gain depth in air tests by turning the ground balance off. Considering the subtractive nature of how the ground balance works I fail to see how it can be otherwise. What you are saying John also directly contradicts the owners manual, page 14: Ground Balancing One of the key features of TDI is its ability to balance out ground mineralization while maintaining pulse induction depths. This is achieved using a differential technique whereby two decay samples are compared; the Ground Balance control is adjusted until the two samples have the same response, thereby canceling the ground signal. Targets below the GB point produce an overall positive response, and targets above the GB point produce an overall negative response. Broadly, the two ranges of targets depend on conductivity, which gives TDI some ability to discriminate. In rare cases a target might fall so close to the GB point that it gives either no response at all or a double-tone response. Because ground balance is achieved using a subtraction method, there is a slight loss of depth any time ground balance is on. Some ground, notably neutral beach sand, is mild enough that no ground balance is needed. In such cases, Ground Bal- ance can be switched off and TDI will run in straight PI mode. This will slightly improve depth, but loses the ability to distinguish between low and high conductivity targets.

Some GM1000 tips and commentary by Bill Southern and others http://www.nuggetshooter.ipbhost.com/index.php?/topic/30778-few-more-gm-1000-tips/

The quote is from Modern Metal Detectors by Charles Garrett, first printing 1985. So Charlie heard about your advice and put his seal of approval on it quite some time ago Norm. Garrett's original books are quite good, before the marketers took over and replaced all the real detecting photos (often black and white and often picturing competing brands in a friendly manner) with posed color photos with models. Prettier maybe but the nitty gritty realness of Charlie's first efforts was lost. I still have a like new first printing copy of Modern Metal Detectors on my bookshelf because of its clear concise text and excellent illustrations. The old version of the book is white - the new "marketers version" is green.

I have had that REI rucksack for so long.... over 30 years, 40 maybe? The zipper in the lid flap pouch is broken. The knapsack is like an old pair of jeans I can't bear to throw away so I guess I need to sew in a new zipper. 1515Art, jumping right into bad ground definitely adds to the challenges and the worse the ground the less reliable any discrimination will be. That flat steel really bangs out hard as a non-ferrous target at 74 kHz. That stuff is a challenge for all VLF detectors. Usually when using discrimination gold will run at the low end of the disc range whereas steel that "wraps high" will come in at much higher VDI readings. The problem is that the higher you go with the frequency, the more all targets shift to the high end of the VDI scale. I need to do some testing on larger nuggets but I bet they read quite high compared to what would be seen at lower frequencies. My gut feeling is that the Deus has a vast array of possible settings to deal with almost anything, but that this is a dual edged sword. For me it gives me a great deal of confidence that I can get this machine to perform well (for a VLF) under nearly any conditions. At the same time that complexity could make certain levels of nuance more inaccessible to some people and outright daunting for beginners. If the Gold Monster represents simplicity the Deus takes it to the far other end of the scale. Most VLF prospectors should feel at home in the Gold Field program however. One issue there. Gold Field is a threshold based all metal program. The threshold is off by default and can only be adjusted with the main controller. If you are trying to operate via headphones only there is no way to adjust the threshold! This means Deus Lite owners or somebody like me that might want to leave the controller at home are out of luck. Attempting to use Gold Field without the controller means no threshold, at least as far as I can determine at the moment. If anyone knows different please let me know. Here is all that can be adjusted directly via either of the Deus smart headphone options: DISC ------------ Discrimination SENS ----------- Sensitivity GND ------------ Ground FREQ ----------- Frequency TONE ----------- Number of Tones VOL ------------- Audio volume COIL ------------ Selected coil or MI-6 P1 to P10 ------- Factory programs I have the WS5 headphones and I like them a lot. Comfortable over ear design like most good nugget headphones. I tried the small backphone version before and was not impressed. If I want lighter weight phones I will just use plug in types. Oddly enough the only Deus volume control is built into the headphones but that option is not available on the main controller, so if using plug in headphones look for ones with volume controls. I tried my ear bud style that does not have a volume control and got a nasty audio blast.

I think in this case it's just designer habit. That's how they made the other DEUS coils so they did the same on this one. A smooth solid design has less edges to catch, is easier cleaning, and in the long run will be more durable. It's like they wanted to make a prospecting coil but are still trying to appeal to their original user base. After using a GPZ so much my first reaction on taking this coil out of the box was "it's so tiny!" I am still struggling a bit with the daintiness of it all. The tiny Deus controller designed for small, clean fingers. Delicate little plugs, wires, and connectors. The little plug that connects the battery to the coil is smaller than any connection I have seen on any detector ever. It's good it does not need to be disconnected to be charged because the opportunity is really there for bending a pin or stripping the plastic threads. It does perform however and at the end of the day that's all that matters. Every detector has physical design issues that we have to accept and work around. I wonder how long it will take before a solid skid plate is available, if ever? I have a suspicion making one myself may be in order.

Something is wrong. Wiggle everything, try another outlet, maybe even use the 12V hookup to a car battery. You should have a blinking green light while charging, steady green when charged. As a Lithium Ion battery it requires no special care or handling procedures. Just use until low or dead and charge up. Does the battery work when placed in the detector? Always have the AA holder alternative as backup. I use it with rechargeable AA batteries and it works fine.

I finally went out and found my first gold nuggets with the new DEUS elliptical high frequency coil. I want to emphasize that I am a newbie on the XP Deus. Although I purchased an 11" Deus V3.2 model almost two years ago, it was with the express purpose of being able to test the V4 update with the new high frequency coil options for gold prospecting. I decided I was better off just starting fresh with version 4.0 before really digging in and learning the detector. I do get the hang of detectors quickly but this does show what can be done by somebody who went out barely knowing the machine. The other catch is that I picked a location that favors the Deus with relatively mild soil for a gold location, so mild I could run the machine full out to get the maximum possible sensitivity with the machine. These results are not going to be as easy to obtain in extreme mineral ground. You have to start someplace however and being new to the machine I wanted to give myself someplace easy to start. Finally, the goal here was to find the smallest gold I could so for the purposes of this report - smaller is better. These nuggets were recovered over the course of a day. Ten nuggets, 4.7 grains total weight. There are 480 grains per Troy ounce and with an average weight of less than half a grain I think you can agree this is some pretty small stuff. The smallest bits are probably near 1/10th grain or 1/4800th of a Troy ounce. Click picture for larger version. Gold nuggets Steve found with XP Deus HF elliptical coil The new HF elliptical coil running at 74 kHz is clearly in the same league as the 71 kHz Fisher Gold Bug 2, 45 kHz Minelab Gold Monster, 56 kHz Makro Gold Racer, and 48 kHz White's GMT. However, the devil is in the details and it will be some time before I sort out how the machines compare under more difficult and varied conditions. Again, I am not an expert with the Deus and so the settings I mention are not to be taken as "the best" or anything like that. I was actually gold prospecting so the primary focus was to find gold, not to test every possible combination of settings on the Deus. With 10 program options and numerous settings that will be a longer term project. I obviously wanted to try the Gold Field program 10. After a little experimenting I settled on the GM Power program 2 as an alternate disc mode to try. Getting from program 10 to program 2 is only a couple button pushes, so I bounced back and forth between the two programs and tweaked settings higher as I found targets and could compare readings. Gold Field is a threshold based all metal mode with what I find to be a rather pleasant digitized buzz. That's me of course, others may differ on that point. I was able to run sensitivity full out at 99. All my work was done at 74 khz, the default highest frequency setting without trying to push it higher via the offset. I figure the coil is tuned at 74 khz and so stuck with that for now. Manual ground balance about 84. GM Power I got sensitivity to 94 with only minor falsing. I reduced reactivity (similar to SAT for you nugget hunters) to 0 from the default of 2 and ran the audio response (audio boost) up to 7 (max). Both modes exhibit just a little touch sensitivity at these high gain levels. This might be tamed with the ground notch but I have not fooled with that yet and it did not bother me at all anyway. What I found was Gold Field has a softer response in general but that my boosted version of GM Power banged hard on the little bits. Not unlike going from all metal mode on the Gold Bug 2 to the Iron Disc mode. Instead of faint threshold variations you get a strong "beep". The difference is that the Gold Bug 2 Iron Disc mode has an obvious loss in sensitivity. The Deus by comparison in this particular situation actually seemed to work better in GM Power mode, but that is mainly the boosted audio at work. I left the disc settings at the defaults for GM Power which worked well - low tone iron, higher tones non-ferrous. I ran the IAR (iron reject) in Gold Field at 2. This was just enough to cause ferrous to break up. Higher settings would blank most ferrous completely but getting to aggressive can also eliminate weak gold signals. The ferrous discrimination worked very well in both programs. GM Power in particular was pretty awesome in the nail pits with iron tones firing off like a machine gun. I bumped reactivity back to 2 in the dense trash. Anyway, this is a very preliminary report and so no point getting too deep into it as I will probably modify my opinions and settings as I get more time on the machine. Right now this is a high price option if all you need is a prospecting unit, but for a person wanting one machine to do everything XP just kicked it up a notch. If they introduce a dedicated gold unit at a lower price similar to the Depar DPR 600 it would be very competitive. For now this is an option for somebody that wants a detector for more than just gold prospecting since the Deus is a superb coin, relic, and jewelry detector. The actual dimensions of the HF elliptical coil are 9.5" x 5". The elliptical coil and rod assembly is just 1 lb 13 oz (1.8 lbs) and so a true featherweight. At 5' 11" I have to run it fully extended and at that it does flex a bit, but I did not find that bothersome at all. A solid coil cover will be good as there are too many coil edges that want to hang up on rubble and sticks. A minor quibble however as the machine is a joy to handle, especially when reaching uphill waist high and higher. A great unit for poking in and around bushes and other obstructions. The coil is hotter at the tips which also helps in poking into tight locations. Early days but the final word is that I am happy with how this coil performs on small gold nuggets after all the wait. Time will tell how it handles the really bad ground and how it fares directly against some of the competition as other people report in. As always giving it time and waiting for a consensus opinion from many users to develop is a wise policy with any new detector. Steve Herschbach DetectorProspector.com September 2018 - New XP ORX announced. This post promoted to an article

The new Deus HF elliptical coil has just slightly smaller dimensions than the 10" Gold Bug 2 coil. The Gold Bug 2 coil is solid and the Deus coil is an open web design. Even more important, the GB2 coil is a concentric as are all Gold Bug 2 coils. The Deus coil is a DD coil. This means the Deus has a more complex response on small shallow targets than the GB2 coil but the DD design may have advantages in more mineralized ground over the GB2 concentric coil.

Something tells me that is a closely held proprietary secret!

The person wanting to name and shame needs to publicly provide their real name and address also so they can deal with the legal issues involved in making public accusations. People have a right to know their accusers. Anonymous accusations with legal implications (i.e. lost business or revenue) will be deleted because otherwise you are laying the liability on me for something I have no knowledge of. No thanks. What you all want to discuss privately is none of my business.

I agree. I should ask more than I do (as editor in chief I don't) but I often change thread names and locations so that the subject line reflects the content of the thread. It aids people doing searches later. I don't alter thread content however unless to perhaps fix a spelling error for somebody or to add links. That said, the thread name has been changed with apologies to Harry but thanks as always for getting it started!

Specifically in your case Harry, do a manual reset on your ATX whenever moving to new ground to start fresh and be sure you do not have overly aggressive settings locked in from the last location. This is critical as the ATX does "remember" the last settings used. Factory Reset All changes made to the ATX settings are saved when the unit is switched OFF. To return all settings back to Factory values, press and hold the RETUNE/ PINPOINT button while switching unit ON. ATX FACTORY/DEFAULT SETTINGS Mode: Motion Discrimination: Zero discrimination (1st LED) Sensitivity: 10 Threshold: 7 Volume: 10 Ground Balance: Neutral Ground Track: OFF

This is a big issue with Minelab GPX detectors. All the "Timings" are is different preset PI ground balancing schemes designed to deal with different ground types. The settings get progressively more aggressive to deal with more difficult ground and hot rocks if you encounter them. You should always run the least aggressive setting that gets the job done. However, some people who do not know their machines and what exactly those settings are doing. Others like myself may know better but fall into bad habits. On the GPX 5000 the Fine Gold setting is a bit of a dream in many severe ground conditions. Bad ground and rocks just disappear! It works so well in bad ground it is tempting to just leave the machine in Fine Gold all the time. However, Fine Gold is a very aggressive timing (filter) and I promise you without a doubt it will tune out and miss certain gold types. If you are running Fine Gold in ground where the Normal mode runs acceptably, you are missing gold. Period. My go to settings in mild Alaska ground were Sharp for large deep nuggets and Sensitive Extra for small gold. Prospectors who can deal with some hot rocks and some ground noise, mainly by mental filtering through tonal differences, can run more aggressive timings like Normal in at least limited small areas that deserve the extra effort. They may dig more hot rocks, but the location if good will most likely also reveal more gold that was previously hidden by aggressive timings. The GPZ 7000 is no different. Here is a thread from a bloke in Australia that has discovered the joys of the Normal versus Difficult ground setting, along with the price to be paid in bad ground by way of noise - but also more gold found. It is often not that you want to hunt like this in general. But if you have a 20 ft by 20 ft area that has really produced, and have a machine with multiple ground setting options, going hot and just dealing with the noise will often reward the operator. Tip - super slow and absolute coil control especially height over the ground. GPX owners - click on the chart below to get the larger version and read the box in lower right (Best Timing) and do pay attention to the depth chart. Note that you can actually turn the ground balance off on a GPX, but I never found ground mild enough to allow it. Beach hunters in Florida take note....

Bingo. You do not lose depth when you ground balance on ground that requires ground balancing. You gain depth by eliminating the ground signal that is blocking the target signal. If you are detecting the ground, you can't detect the target. However, by employing any filtering system (discrimination, audio smoothing, ground balancing, etc.) where it is not required you are going to block possible responses that do not need to be blocked. This is easily seen with the White's TDI which allows you to turn the ground balance on and off. In air tests (and low to no mineral ground) you gain depth by shutting the ground balance off. As the ground gets worse and ground signals intrude, they mask target signals. At that point engaging the ground balance eliminates all the ground noise allowing you to hear the targets. It does cost you depth in absolute terms, but it is a moot point because eliminating the ground signals is paramount. This page Link deleted since Findmall Forum update broke all old links has some depth tests with the TDI and ground balance on and off. The settings: Air = Gain max, Ground Balance Off, Pulse Delay 10, Frequency 12 o'clock, Conductivity All, Threshold hum. Low = Gain max, Ground Balanced at between 7-8, Pulse Delay 10, Frequency 12 o'clock, Conductivity LOW, Threshold hum. All = Gain max, Ground Balanced at between 7-8, Pulse Delay 10, Frequency 12 o'clock, Conductivity ALL, Threshold hum. Check out the chart paying particular attention to the Air vs All measurements. The air depths are close to what you will get for depth using no ground balance in "no mineral ground" i.e. pure white Florida coral sand. The chart also highlights how in low mineral locations an MXT may be the better choice. For machines that have the capability however it is important to know this because running ground balance where it is not needed does rob depth. And in very low mineral ground savvy VLF operators can sometimes gain depth by purposefully offsetting the ground balance control. If the ground is not signaling over a wide range when you change the setting, is it better to set lower or higher? It depends on the targets sought and knowing how your machine performs inside and out. Hint - if your detector has a ground balance control that goes from 1-10 then take a quarter and a nickel. Air test both at GB setting of 2 and GB setting of 8 and observe what happens. Double dark secrets of the pros...

Very nice find, congratulations! Funny story - the first decent nugget I found I had made into a pendant for my wife, who them informed me gold nugget jewelry is not really her thing, so she gave it back to me! I wore that thing as kind of a good luck piece for many years. Guys wearing gold chains is not the thing it was however and that nugget necklace has now joined the rest of the gold in the safe deposit box. The only jewelry I wear these days is a plain gold wedding band I found in Kauai.

The discoloration you had to clean off is discouraging. Gold does not tarnish and 99% of the nuggets I find pop out looking like gold except for attached dirt or caliche. From https://portlandgoldbuyers.com/gold-testing-nitric-acid/

Awesome write-up, thanks Nenad!

I will almost always opt for power over weight when it comes to nugget detectors. However, with VLF performance so hair splitting close these days it is things like weight and balance that can be the deciding factor between two detectors with otherwise similar performance. In general I agree with others - I need better discrimination more than I need more depth. There are plenty of machines that punch deep but they are the very ones with the poorest discrimination features.

Enough that you are unhappy you got it? If so, I apologize for the recommendation.

Unfortunately gold depletes. Nugget hunters face the fact that every nugget dug from a patch depletes it until the gold is gone. It never comes back. I used to think "that's fine, I will just switch entirely to jewelry detecting some day since jewelry is constantly being lost. The beach will never run out of gold." I have come to realize however that any virgin park or beach of age has 100 years or more accumulation of jewelry. Very similar to silver, these "old jewelry" finds provide the bulk of the jewelry these locations give up. However, the rate of "fresh drops" or newly lost jewelry is quite slow, and due to constant detecting these days comes nowhere close to replenishing the jewelry. I think what we are all experiencing is initial enriched old jewelry getting cleaned out, leaving nothing left to find but new finds which are very sparse. The rate of loss must vary for jewelry by site depending on many factors. I am just making this up, but imagine a 100 year old beach where one gold ring is lost each year. 100 rings to find. The first people in have great success because of the old ring accumulation. As that old gold depletes however, there is only one new ring per year to replace it. Eventually you get to where everyone is fighting to be the first to find that one ring. Therefore while jewelry does replenish, it is quite likely that it will get increasingly difficult to make good finds, and we are seeing that result already. This is compounded by the trend to junk jewelry as young people would rather invest in a new iPhone than a quality gold or platinum ring. Cherish those quality jewelry finds. They will never cease entirely but I do think that just like we are seeing nugget detecting, the "golden age" of jewelry detecting is largely behind us. I am not trying to be a bummer about that, just trying to explain what I am personally experiencing and hearing from others over the last 20 years. With all that said, ring pull tabs are good! They are an indicator old gold remains to be found. If a location is cleaned out of pull tabs, the likelihood is the old gold is gone also.

I almost always use a classifier when panning. It both greatly speeds up the process and you also get better recovery. Double benefit. Personally I normally used one of the standard plastic classifiers. Always at minimum give the oversized discards a quick eyeball - you don't want to toss a large nugget!