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I am somewhat new to metal detecting and was recently told, by a veteran detector, that all machines are multi frequency. I was also told to not buy into the multi frequency hype and that machines advertised as ones, is a marketing ploy. Please help! Is he right?

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Welcome to the forum! No, that is inaccurate. One simple example is saltwater - multifrequency machines have a clear and indisputable advantage there. Target id accuracy is another area of clear superiority. These are not opinions; there are clear technical reasons why this is so. This article will tell you more about the subject.

Selectable & Multiple Frequency Metal Detectors

That is not to say you can’t do well with single frequency or that single frequency does not excel at some tasks. There is generally a situation in metal detecting where any one methodology can have some advantage.

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Either you misunderstood the veteran detector user you talked to or they have a bone to pick with a certain type of detector. Most hobby VLF detectors are single frequency. Depending on their quality they may be able to very slightly change frequencies in order to prevent crosstalk with other detectors. Only a few VLF detectors have the ability to selectively change from one detecting frequency to another like the XP Deus, XP ORX and some of the Nokta Makro detectors. A very few detectors also have the ability to operate with simultaneous multiple frequencies. Depending on if your soil has high mineralization conditions or if you detect saltwater beaches, a simultaneous multiple frequency detector may be the only VLF detector that will work well. In very mild to moderately mild dirt you won't see much difference between a good quality single frequency detector and a good quality simultaneous multi frequency detector for shallow to medium depth targets. On the deeper targets (past 6 to 8") the simultaneous multi frequency detector may out perform the single frequency detector as far as identification of the target is concerned.

So, simultaneous multi frequency detectors work very well where many other detectors fail miserably. That is not hype or some kind of marketing ploy, it is a well known fact.

Jeff

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I think the location your hunt is the single most important part to finding something good followed by knowing your machine and having the right coil for the job.

I hunt more by audio than vdi so if the numbers are a bit dodgy it means very little to me but that is just the way I hunt. Others keep their eyes glued to their screens.

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24 minutes ago, kac said:

I hunt more by audio than vdi so if the numbers are a bit dodgy it means very little to me but that is just the way I hunt. Others keep their eyes glued to their screens.

I have read this response in your posts before and on many detectors with or without displays that strategy works very well. On some simultaneous multi frequency VLF detectors being hype or not, which is the topic of this thread, visual target IDs are very accurately accompanied by very accurate multiple tone ID capabilities. On the Equinox specifically, I hunt first by tone ID and use the numerical target IDs to support what I hear. I don't know anyone who uses an Equinox (that knows what they are doing) that has their eyes glued to the screen. They don't need to especially in 5 or 50 tones. 

Jeff

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Yup, what Jeff said. It has nothing to do with the target id information being presented in an audio or visual fashion. It’s is all derived from the same base information, and if one is inaccurate, the other will be also. An aluminum beaver tail that reads like a dime will also sound like a dime, a common occurrence with single frequency in bad ground, but does not happen to me with multi.

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8 minutes ago, Steve Herschbach said:

Yup, what Jeff said. It has nothing to do with the target id information being presented in an audio or visual fashion. It’s is all derived from the same base information, and if one is inaccurate, the other will be also. An aluminum beaver tail that reads like a dime will also sound like a dime, a common occurrence with single frequency in bad ground, but does not happen to me with multi.

  With my xterra 70 many pulltabs  would up  average to coins. In places where  I  didn't mind digging more targets or when the  depth of  up average was where their would be old  nickles or gold rings  I did   not care to much.If the pulltabs and coins were both very deep because of soft ground,that up average thing the  machine did made it tough when you were focused on silver coins or you were cherry picking  .I like the nox Id. It is good enough for me to know it's a coin.

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I was about to say the same thing, the audio just seems to represent the exact ID on the screen so having inaccurate ID's on the screen would also mean your audio is out of whack.    If hunting by audio you're still listening for that sweet tone of the target you're chasing and the tone will represent the number of the target.  I used to hunt exclusively by screen, as I've aged on my detector I've started to use tones a bit but for me nothing beats ID's on a screen.   The tones may pull me up on my lazy wander through a field but in the end for me the screen is what gives me confidence to dig.    In fact I'm still blown away my detector can throw up a number and I dig that number and 10 inches down is a little silver coin, the exact coin the number was telling me it is.... what a neat technology.

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My AT Pro with latest firmware and 9x12 concentric audio and vdi match right to the fall off (older firmware numbers would drop off but audio was still there). The MK has very reliable numbers when gain is not maxed out. 80-85 is where the machine should be and gain above that your simply pushing the machine. In Gen Mode that the vdi #'s are just raw unfiltered response.

When I say I hunt by audio first I do that to judge the target size and depth. My last large cent the numbers were all over the place and buddy passed over it with his Nox 800 for the same reason. Turned out there was a tiny bit of iron in the same spot. Coin was only 6" down. Out here hunting for size of an object has helped me more so than the numbers.

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14 hours ago, Jeff McClendon said:

On the Equinox specifically, I hunt first by tone ID and use the numerical target IDs to support what I hear.

That^

14 hours ago, Steve Herschbach said:

It’s is all derived from the same base information, and if one is inaccurate, the other will be also. An aluminum beaver tail that reads like a dime will also sound like a dime, a common occurrence with single frequency in bad ground, but does not happen to me with multi.

The only thing I can add to this is that there are tonal nuances that can provide clues.  Yes if you have junk that gives the same ID as a desired target (Steve's dime/beaver tail example) you will get the base tone ID that corresponds to the visual target ID, but on some detectors, especially those that have audio modulation with depth, whether they are multi F or single F, then if the target is irregularly shaped and not perfectly round, can sometimes hear a distortion or tonal sideband nuances in addition to the fundamental ID tone that tell you maybe that is a corroded zinc, bent tab, or slaw even if you get a rock solid ID.  I have found that the Deus/Orx, especially in pitch mode gives you this nuanced information better than the Nox (but no target ID), similarly on the Nox, sometimes Gold mode can do this too.  I like 50 tones on the Nox because if the target ID is unstable (usually a dead giveaway for junk unless there  are multiple targets in the "hole" or more correctly under the coil - like KAC described with his large cent or a coin spill) you can just hear that right off and decide whether you need to circle the target to lock in the ID, move on, or just dig it out to be sure.  Bottom line, it is both the audio and visual ID information and how the target responds to coil movement and perhaps a shift in modes/frequency (that is why having that single frequency option on a multiF detector is important to me)  that all combine to give you the clues so you can make your best dig decision - I call this interrogating the target.  Regarding the Nox, since it has less tone modulation than other detectors, I find the pinpoint to be a useful tool for "sizing up" the target otherwise, Nox's gold mode pseudo VCO audio is also a useful tool, so I usually keep a gold mode program in my Nox's user profile slot to interrogate an iffy target.  Bottom line, though, these target interrogation techniques and audio clues work regardless of whether the detector is single or multi frequency, but the language varies from detector to detector due to the detector target ID feature implementation differences. 

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      1994 Compass X-200                6 kHz    14 khz
      1997 Minelab XT 18000            6.4 kHz    20 kHz    60 kHz
      1999 Minelab Golden Hawk        6.4 kHz    20 kHz    60 kHz
      2002 Minelab Eureka Gold        6.4 kHz    20 kHz    60 kHz
      2005 Minelab X-TERRA 50                7.5 kHz    18.75 kHz
      2006 Minelab X-TERRA 70            3 kHz    7.5 kHz    18.75 kHz
      2009 Minelab X-TERRA 305            7.5 kHz    18.75 kHz
      2009 Minelab X-TERRA 505        3 kHz    7.5 kHz    18.75 kHz
      2009 Minelab X-TERRA 705        3 kHz    7.5 kHz    18.75 kHz
      2009 XP DEUS                  4 kHz     8 kHz     12 kHz     18 kHz
      2016 Rutus Alter 71        Variable 4 - 18 kHz
      2017 XP DEUS V5           Additional 14 kHz    30 khz    55 khz    80 khz options
      2017 Nokta Impact            5 kHz    14 kHz    20 kHz
      2017 Makro Multi Kruzer            5 kHz    14 kHz    19 kHz
      2018 Nokta Anfibio            5 kHz    14 kHz    20 kHz
       
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      1991 Minelab Sovereign            BBS
      1999 Minelab Explorer S/XS        FBS
      2001 White's DFX            3 kHz & 15 kHz (Simulates single frequency by ignoring half the dual frequency signal)
      2012 Minelab CTX 3030            FBS2
      2020 Minelab Vanquish             Multi-IQ
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      1995 Fisher CZ-20             5 & 15 kHz (CZ-6 in waterproof housing)
      2001 White's Beach Hunter ID   3 & 15 kHz (DFX in waterproof housing)
       
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      2020 Garrett Ace Apex   5 kHz or 10 kHz or 15 kHz or 20 kHz plus multi frequency options
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      I personally think we have seen enough variations of single frequency detectors. I do not believe much can be done to exceed the performance of the dedicated single frequency VLF type machines we currently have. What can obviously be done is a better job of packaging machines that deliver true punch at different frequencies, or multi frequency machines that bring across the board performance closer to what is expected of PI detectors. I do think we are seeing this happen now. The new Nokta Impact and the new DEUS V4 update are expanding the available options in selectable frequency in more usable packages. The Minelab GPZ and other hybrid platforms blur the line between what is traditionally considered PI and VLF and simply need the addition of discrimination to go to the next level. There is still a lot of potential to deliver machines that might reduce the number of machines many of us feel compelled to own by delivering more across the board performance in a single machine that would now take several detectors. Exciting days ahead.
      For those who want to try and get their head around selectable frequency and multi frequency technology, Minelab and White's have a gold mine of information in a few of their references. Dig into the following for some great explanations and diagrams.
      Minelab - Metal Detector Basics and Theory
      Minelab - Understanding Your X-Terra
      White's - Spectra V3i Owners Guide
      White's - V3i Advanced Users Guide
      Better yet are the last three parts of the DFX instructional video by White's featuring engineer Mark Rowan explaining frequency and multi frequency methods:
       
       
       
       
    • By Abe2020
      Is this detector able to detect diamond? I am trying to find a diamond from a ring that fell out a number of years ago in my  garden. My friend Aberal Molzesman said in his blog tha it is possible.
    • By Steve Herschbach
      Steve's Law of Target Depletion - All good locations with high value targets will be detected with progressively more aggressive means until no metal can be found. When any location contains items of great perceived value, detector technology will normally be applied in reverse order of aggressiveness. First will be VLF discrimination "cherry picking". This will be followed by varying degrees of "turning down the discrimination" to dig iffy targets and then on to using the barest of ferrous/non-ferrous discrimination. This will finally be followed by "all metal" detecting to remove masking effects with either VLF or PI detectors. If the location is considered good enough all targets will eventually over time be completely removed until no detector is able to acquire a target. At this point a site may be considered "hunted out" until a new technology arrives allowing for more depth or ground separation capability, when a few more remaining metal items will be removed. The key concept is that since discrimination is unreliable, all metal items must be removed from high value locations in order to rest assured nothing has been overlooked.

      Nugget hunters and beach hunters get right with the program. If a nugget "patch" is located it will be relentlessly pounded until no metal remains. Beaches survive to some degree by being a renewable resource but even on beaches the richer, older deposits of jewelry are worked out over time. Good relic locations can and will be subjected to the same attention given to nugget patches, detected relentlessly until no metal remains. The rule is that as long as you can find a piece of metal hope remains that good items can be found. If not you, somebody else can and will return until no metal remains. I have promoted PI detectors for all uses for this very reason for over 15 years now - see that last few paragraphs at www.losttreasure.com from 2005.
      Most people consider depth to be problem number one, but for many areas target masking is by far the more serious issue. Until detectors can actually see through trash instead of blocking it out, even the smallest surface trash can and will block deeper adjacent items from being detected. Superb discrimination only gets you so far and ultimately the only solution is to remove the surface trash to see what lurks below. The only real limitation we face in this regard is in areas sensitive to digging holes of any sort, like a well groomed park. Even there, slow careful extraction of surface trash over time can reveal old coins missed by others for decades.
      Beneath The Mask by Thomas Dankowski
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