Chase Goldman

Doubtful, I have the Legend and 900 so I am not seeing it as a fit for me as a backup or otherwise. But it is a great value and I am VERY interested in how it does, especially at the beach, to see if it can hold its own as single frequency machine up against the Nox and Legends out there. Certainly, at that price, it's hard to go wrong. I think it's proven its worth as a solid general purpose detector already What are you using for phones?

Thanks. Good info. Keep sharing your experiences with the Xterra Pro and happy hunting.

What tone settings are you using? Tone should stay consistent in something like 5-tones (or less) as long as the TID variation does not cross a tone break. Are you saying that the tone stays consistent even if it crosses a tone break? (If I recall the upper three breaks of 5-tone tone are at 20, 56, and 84, so I would expect some tone variation on the "high" bounces above 84.). Much appreciated.

So I did that with some quick and dirty air testing with my Nox 800 and the 6-inch coil (happened to be the coil I had bolted on, but it also provided a quieter test bed as I was able to crank sensitivity up to about 23 for all frequencies in my wi-fi saturated neighborhood). Ran a zinc penny, modern nickel, clad dime, and clad quarter across the coil (air test) at 4 khz, 5 khz, and the dime and quarter across the coil at 20 khz. The noise situation was such that I was able to run sat noise cancellations on all frequencies to get quiet channels on all 3 frequencies at Sensitivity 23. After running this test, I'm convinced that: 1) There is no signficant differences in air test detection depth between 4 khz and 5 khz for each of the targets. 2) The dime and quarter at 20 khz saw a loss of about 1/2 to 1 inches air depth vs. the 4 and 5 khz air test runs. Conclusion: "Quiet" 4 khz on the Nox does not come at the obvious expense of performance versus "Noisy" 5 khz and at 20 khz, all other settings and factors being equal, you take a performance hit on high conductive target depth vs. 4/5 khz, which is not surprising. As the resident doubting Thomas here, Dig, I know you are not going to take my word for it and will want video proof. Well, I leave it to someone else to go to the trouble of convincing you with that objective evidence. In the meantime, I welcome you or anyone else to share or post results of similar 4 to 5 to 20 khz testing and would definitely be interested in any results that differ from mine. But for now, I've convinced myself that 4 and 5 khz are basically equivalent in depth performance and I've seen 4 khz excel in EMI situations that shut down 5 khz, and to me, that's all that matters. Regards.

May the Fourth be with you, CAPT.

I disagree with the absolute "can't know the difference" statement as there are probably sophisticated ways to use signal processing and machine learning (assessment) to determine with good certainty the nature of the magnetic field disturbance (i.e., target based, EMI based, or ground based) under normal search conditions and to dynamically change filtering. I don't know of any specific detector that does this...yet, but I find it totally plausible. Automatic ground balancing does this to a certain extent by continuously monitoring the level of ground mineralization, and executing a ground grab when signficant changes in mineralization are sensed. But it can also be fooled by ferrous targets. But for today's detectors we are instructed to set up specific initial conditions so that basic assumptions can be made (or directly measured) to execute semi-automatic noise cancel (frequency shift/filtering) and ground balance routines. In the former, the detector "brains" either know (via a sensor) or assume the detectrorist is following instructions and the coil is NOT moving so any magnetic field imbalances must be due to EMI. Similarly, during ground balance, the machine "knows" or "assumes" you are swinging or pumping the coil over target free ground, so any magnetic field imbalances must be due to ground conductivity. Either way, we trust the designer not to significantly degrade performance while going about the process of finding a quiet channel or setting the ground reference point, as instructed. Be curious all you want. But continuing to ask forum members here "why" or "how much" performance is affected by these EMI and ground noise cancellation routines is just unverifiable speculation precisely because we are not privvy to the specific design details. I you want to get down and dirty into this type of technical detail, I suggest visiting Geotech's (Carl Moreland's) excellent detector design focused forum. https://www.geotech1.com/forums/forum Carl is a forum member here. Has written a number of books on detector design that are referenced in Steve's detector resources list. Cheers

Dig - none of us can prove or disprove any of this because we didn't design these rigs. So if you want concrete answers about what's going on under the hood. Ask the manufacturers directly. Who knows, maybe they can answer your questions without giving away state secrets. Those using the Equinox don't really care how ML made 4 khz quieter, they just know from experience it is, they can run higher gains than 5 khz, find decent targets at depth, and are not seeing any noticeable performance hit (even if there is a slight gain reduction). Simple as that.

Against my better judgment... Jeff is saying that you keep bringing up this hidden gain reduction premise, yet no one is reporting target depth loss at 4 khz vs. 5 khz in situations where you can run either at max sensitivity. Further, your 20 khz "solution" ignores the fact that there is discrete loss of target detection depth, especially for high conductive targets, by going from 4 khz to 20 khz and unlike your stealth gain reduction conspiracy theory, that's a given performance hit.

The Quest Wirefree mate should work with both Nox 800 and Nox 900 by plugging the Quest transmitter into the headphone jack of either detector.

Unfortunately, Nokta doesnt have a WM08 for Legend and uses a proprietary waterproof combo headphone/data/charge connector on their Legend/Simplex control boxes (which also makes using their outboard extended battery impossible with a wired loadspeaker or headphones). But Erik's nifty device will work with Legend (and Nox for that matter) with an APTX-LL BT receiver as an alternative to the Nox's WM08. Unfortunately, no WM08 equivalent or even APTX-LL receiver equivalent for the Nox 700/900 or Manticore as they use the latest and greatest BT LE Audio but there are no third party BT LE equivalents to these receivers out there quite yet. Because of the wonky Legend speaker and external wired audio limitations, I use the Avantree Torus neckband speaker with built-in earbuds so with one device I have a near field speaker or privacy as I see fit. I've used it with the Nox 800 too (and it is popular with GPX 6000 users). But it lacks onboard tone adjustments and the ability to plug directly into an audio source like Erik's device (which also appears to have a headphone jack of its own to pass through audio...nice).

Suit yourself. Maybe someone else will get something out of it. But I'm moving on from this merry-go-round discussion. It's like Ground Hog day and non-productive, tbh.

So why bother to continue to flog a dead horse? You want someone to prove a negative which is basically impossible. But knock yourself out. I'm tapping out, so congrats.

It wasn't an illusion, its just one of several legitimate ways to attack the issue. The F75 was on the ragged edge sensitivity wise, so they dialed it back slightly and used digital signal processing to cancel EMI. They also made it so you could switch DST on or off if you were concerned about weak signal masking. As Steve said in the EMI thread I linked above, the additional sensitivity is worthless if all it is doing is amplifying the noise floor.

Taking the time to read the technical references reveals that the rule or generalization or whatever you want to call is applicable mainly to power line noise sources. But given the growing proliferation of 5G transmitters and WiFi 6, solid state switching power supplies, and LED lighting, even detectors with higher operating frequencies will be affected more in suburban and even rural areas as time goes on as evidenced by Steve's anecdote about his noisy 19 khz detector.

To that point regarding TID, Chuck, you can also see where things take take a step backwards even when we think we are moving forward. Reference the TID stability issues that have been noted on the Nox 700/900 compared to the Nox 600/800 and even Manticore is wrangling with TID stability to a certain degree. This probably just illustrates the "no free lunch" adage as Minelab opened up the TID scale to provide better mid-conductivity target ID differentiation, but so far, it has come with a cost - less TID stability overall.

Without getting into a prolonged back and forth as to whether "...by far, that generalization is empirically and experientially true", I'll simply link to this excellent thread by Steve that addresses that generalization but also discusses exceptions. A deeper dive into the thread's technical references and the complex nature of EMI reveals that it's hard to lean too heavily on a single, convenient truism as the variables that affect the outcome of how a detector responds to the vast variety of EMI sources are also numerous. Nevertheless, some great nuggets about detector EMI susceptibility and what you can do about beyond sensitivity reductions and frequency shift based noise cancellation routines. FWIW, I was still curious and asked an expert a general question about metal detector EMI susceptibility and operating frequency and this is what they said about it: Metal detectors that operate at higher frequencies, typically above 10 kHz, are more susceptible to electromagnetic interference (EMI) than those operating at lower frequencies. This is because higher frequency signals are more prone to interference from other electrical and electronic devices, including power lines, cell phones, radios, and other metal detectors. At higher frequencies, the metal detector's circuitry and coils are more sensitive to changes in the surrounding electromagnetic field, which can cause false signals and reduce the detector's overall performance. In addition, the higher the operating frequency, the more likely the metal detector is to generate EMI, which can interfere with other electronic devices in the vicinity. To minimize the effects of electromagnetic interference, metal detector manufacturers often incorporate features such as ground balancing and sensitivity adjustments, as well as shielding to protect the circuitry from outside interference. However, even with these measures, it is still possible for metal detectors operating at higher frequencies to be affected by EMI, particularly in areas with high levels of electromagnetic activity. That expert...ChatGPT. 🤣 Clears things right up. SMH

First of all, one needs to be careful about generalizing EMI and the impacts based on operating frequency. Different detector operating frequencies have different susceptibilities to different EMI sources like 60 hz power line or florescent light balun noise vs. GHz wireless device noise (cell towers, phones, and wifi) and everything else in between. So its hard to generalize that high frequencies are generally quieter than lower operating frequencies. There are scenarios that I have encountered that are just the opposite of that. Also, EMI can interfere with detector operation from several different avenues and can enter the detector from more than just through the coil acting as an antenna. Operating frequency selection determines how target signals are filtered as they are processed. But the control box can pick up sources of EMI independent of the operating frequency selected and changing the operating frequency (the typical noise cancellation algorithms) doesn't necessarily fix those issues. Regarding the update, ML apparently did something to address EMI and ground handling with the 4 khz "mode" vs. the 5 khz "mode" and it had little to do with the actual operating frequency other than ML probably surmised that if they could make a lower operating frequency mode less susceptible to EMI then whatever they were doing could be used effectively across the board. Furthermore, they also needed to be concerned about unforeseen consequences such as reduced depth or target sensitivity, hence they left 5 khz alone in the event their "experiment" had unintended consequences. True, in general there is nothing that makes 4 khz signficantly less susceptible to EMI than 5 khz, but ML must have incorporated some secret sauce to make the added 4 khz mode to be less susceptible or more stable than the existing 5 khz mode. That extra 4 khz can also make a significant difference on detection depth for large, high conductive targets.

Minelab introduced 4 khz as a feature "upgrade" a few years after release. Minelab stated that it was at the request of Asian "horde hunters". Yes, most were skeptical and scratching their heads regarding the additional frequency given that it was so close to the existing 5 khz setting. I am pretty sure ML was experimenting with SF noise mitigation, ground handling, and signal processing algorithms as many users noted that 4 khz was incrementally more stable and perhaps had incremental improvements in detection depth on high conductors vs. 5 khz. In hindsight, it was probably a stealth field test of single frequency enhancements that ML was considering for incorporation into future detectors such as the Manticore, but more likely, this was a test case for enhancements that were eventually incoporated into the X-Terrra Pro.

Garrett does not outsource production. Don't know about First Texas. FWIW - Minelab (Australia) outsources production to Malaysia.

You make valid points about advances in machine versatility and I too would not pull out my MXT or F75 (I still have them collecting dust) instead of my D2, Nox, or Legend, either. But that cannonball comment was in the context of fundamental detecting technology advancements (the detection technology principle), so yes, I stand by it. In that context, my view is that we are basically squeezing what little juice is left in the induction balance principle base technology that is the basis for hobby discriminating metal detectors. I honestly have not seen anything progress significantly other than bells and whistles and price points after Equinox was introduced 5 years ago. What Equinox brought to the table was incredible versatility vs. raw capability (a true all terrain, all situation detector that performed just about as well as any other detector out there) at an affordable price point. It ushered out the era of specialized niche detectors for hot dirt, gold, and salt water. But there was nothing really new in detecting technology other than a further refined iteration on SMF (been around for decades) and finally taking advantage of processing speed and embedded signal processing and user interface capabilities that have been present in phones and personal computing devices for a decade or more. Oh and manufacturers seem to be paying more attention to ergonomics. Since then we have had Garrett attempt an entry level SMF that was barely a blip on the radar screen. Legend which is just an iteration on Nox with affordability that, yes, makes it more accessible to the casual detectorist, and Deus 2 which is a hybrid of the Nox and Deus 1 that is still outdone by Nox in some respects. Manticore is also just an incremental evolution of Nox, to be honest. The advances have been mainly cost, terrain versatility, user interface enhancements, and ergonomics, not necessarily a step change in capability or fundamental technology. So with respect to recovering targets with the classics like the MXT and F75, experts with those machines still can hold their own against the Manticores of this world on nominal terrain. Sure, there is some hot ground and wet salt sand advantages to the latest machines vs. the Fisher and Whites standard bearers but again, that's improved versatility and reducing the need for specialized machines like PI's, Gold Monsters, eTracs, and Excals. Yes, we need fewer "specialized" detectors now, and that's a good thing. But if you are a long-time detectorists with a classic machine primarily looking for spread targets in mild soil which is the norm rather than the exception in the US, the case for upgrading from an MXT or F75 is not necessarily there. In other words, if Nox or Legend or even Apex did not sway you, what will Garrett do to make a dent now that the market is saturated with 4 generations of Minelab Multi-IQ machines, a dirt cheep selectable frequency machine, the Legend, a forthcoming Quest, and the higher end Deus 2 and Manticores. In other words, how does Garrett make a splash with the holdouts who have not seen the need to upgrade from an F75, MXT, or AT Max over the past 3 to 5 years?

Incredible button. That is an amazing design and to end up in a catalog. Fantastic.

An affordable, safe, and compact imaging detector.

Yep. Agreed. I Mentioned that in my previous post.

Agree. It may really be too late for the US manufacturers to get back in the game. There are also niche players in the US with interesting and different approaches to detector design such as Tarsacci. But they are small and niche so difficult to gain any significant market share or make a splash except for a few dedicated fans.

Not sure what one has to do with the other. It just shows that Rutus doesn’t have a strong marketing presence with detectorists in the US vs. XP, Minelab, Nokta, and Quest despite having a great design. All of these non-US manufacturers have products that far exceed anything the US has to offer at this point. I don’t think the US manufactures are oblivious to products like the Atrex, just as they know they are getting their clock cleaned by the other better known Non-US players. Also, as seen in this thread, a not-insignificant contingent of folks in the US are willing to continue to cling to their Classic MXTs, AT Pros, and F75s at this point, despite the demonstrated performance and features gains of these foreign detectors. Not sure what to do with that but I think it has something to do with the fact that they still work and find plenty of targets and the users are intimately familiar with their quirks and secrets (knowing your detector well generally trumps superior tech in the hands of a newbie). And like I said previously, these “significant” advances in detector tech, in reality, are only incremental and really only marginally increase finds in the grand scheme of things. The key being not technology so much as finding and gaining access to the shrinking number of sites that produce finds.