Anyone know how many FBS frequencies the Quattro MP transmits? Andy?

[Anonymous]

Minelab makes a point of advetising 17 BBS frequencies for the Sovereign/Elite and 28 FBS frequencies for the Explorer line, but do not do so for the Quattro MP. I assume it's between 17 and 28, but maybe it's fewer than 17. Anyone know? I've emailed Minelab, but they're taking a long time replying.

 

[Anonymous]

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[Anonymous]

It uses FBS circuitry with 28 frequencies. It can use any coil or accessory that the Explorer uses; Sun Ray coils/X-1 Probe, Coiltek or Explorer coils. Minelab is closed for their convention. Good hunting, David @ Dixie <center><a href="http://www.dixie-metal-detectors.com"><img src="/metal/html/d-m.jpg"></center>

 

[Anonymous]

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[Anonymous]

I know it transmits 28 but does anyone know how many it actually receives AND processes?

 

[Anonymous]

You are one of the first that I have read to ask the real question to frequency. It is how many are processed that counts.
If a square wave is used to drive a TX coil then you have the fundamental frequencies and odd harmonics. The harmonics have a decrease in power so that the third hamonic is 1/3, the fifth is 1/5 and so on of the fundamental frequencies. It takes Fourier Analysis, math modeling and analysis, to see the harmonics of fundamentals. A square wave drive coil has both the fundaments and harmonic in the TX and RX coils but are they process in the receiver circuits.
As an example, the DFX has 16 frequencies as the cTX coil is driven by a square wave. However, only the 3khz and 15khz signals are processed in the receiver due to agreements with Minelab who ownes the patents for the process. No one can patent the frequencies.
What follows is an opinion from looking at the patents, and using and testing the Explorer. I believe thate are thee or four fundamental frequencies and the harmonics for total of 28. Noise cancel shifts the band width between frequencies and each shift is a channel.
However, it looks to me that all 3 or 4 fundamentals and all harmonics are processed for a total of 28 frequencies. I say that becasue of the fine level of discrimination that can be obtained with the Explorer. Also, the lower end of the FBS is for deeper targets while the upper end is for more shallow targets. The same rules that apply to frequency and size is also a factor.
<span style="background-color:#ffff00;">In contrast a sine wave drive coil is a fundamental single frequency detector.</span>
<STRONG>A major advantage of multiple frequency is the ground balance and tracking can be to both iron oxides and salt at the same time for multiple frequency.</STRONG> A single frequency detector can only be ground balanced to salt or iron oxides at any give point in time.
<STRONG>A MAJOR factor in depth is ground balance and discriminaiton. The Explorer is outstanding in both areas due to the number of frequencies used.</STRONG>
YOu did not ask but if the Quatro uses the same front end and 28 frequencies does it make sense that it would get more depth, be less complicated to use, and cost less? <span style="background-color:#ffff00;">The answer is yes and no in that if the front end is the same then the electromagnetic field from the coil is the same so it penetrates to the same depth.</span> However, with a new processor and improved receiver circuits it could in theory be more efficient in selecting faint target from the composite signal in the receiver that is the fundamental frequencies and the harmonics. But why pay more for an Explorer is it is more difficult to use, gets less depth, and cost more?
<span style="background-color:#ffff00;">It makes sense to me from what I have read and my own understading of electronics that the depth is the same between the two detectors.</span> If that is true than why purchase a Quatro? There is where I believe the actual reason for the the Quatro. Number one is it is simpler to use and based on some solid best sellers for other manufactures as far as presentation is concerned, it cost less, get the same depth as the Explorer, but simply has less features.
The Quatro is a Explorer with less features, less cost, and has a quick learning curve, with some of the features that are well received on other brands of machines and makes a great primary or backup machine. However, the song and dance about depth is just that. <STRONG>You still get your money's worth in features if you prefer the Explorer. As a matter of fact I am going to get a Quatro in because I consider it to be a very attractive addition to the lineup.</STRONG>
HH, Cody

 

[Anonymous]

Cody,
After a somewhat less than thorough study of the Minelab patent 5,537,041 , it seems rather obvious that the detectors are time domain machines. They transmit a rectangular pulse, followed by an opposite polarity rectangular pulse. The processor then analyzes the time domain response of the two half cycles (See Figures in the Patent) to determine the nature of both the ground mineralization and any metal target that may be present..
It has never been clear to me why the detector is referred to as a 28 frequency machine. Frequency seems irrelevant when one considers the time domain behavior.
Can you clarify this for me?
HH,
Glenn

 

[Anonymous]

Glenn,
With a single frequency detector is it easy to talk about Time Domain and frequency. A 6.5khz sine wave that drives a single frequency detector is pretty ease to describe and talk about. Driving the TX coil with a rectangular waveform would be difficult to PR as a Time Domain detector when we all think of frequency so need to go to frequency domain to PR the machine. My assumption is the rectangular wave is split out in the receiver into 28 frequency.
I agree to say that the detector is a time domain machine would make a lot of sense to a technician or engineer that works with time domain on an oscilloscope. However, to the consumer and to PR the detector it looks to me like it is best to specify the number of frequencies that the rectangular wave is split into. That gives a lot of room to talk about frequencies, ground balance, discrimination that is a little hard to do in terms of the time domain. I further assume there is some type of circuits that do use Fourier to take into consideration the time domain and frequency domain. I cannot find anyone that is willing to explain it so these are my assumptions.
Anyhow, the rectangular waveform that drives the coil is split into 28 frequencies in the receiver. Exactly how that is split as far as fundamentals and harmonics is not clear. It would seem to me that seven fundamental to the forth harmonic or four to the seventh harmonic would make sense. This is an area where no one is talking that I know of.
HH, Cody

 

[Anonymous]

You said, "with a new processor and improved receiver circuits it could in theory be more efficient in selecting faint target from the composite signal in the receiver that is the fundamental frequencies and the harmonics."
If the quattro is indeed a new machine from the ground up, then this is probably true. However, considering the limited market of detectors and the costs of re-tooling a factory, I would guess that all that has been done to the quattro is that new software was written (to disable some features) to run the same board with less buttons. The answer would probably be obvious if same a unit of EX and the Q were opened and laid side by side.
I would further this speculation to include that if indeed the Quattro is an entirely new detector, then possibly the EX is up for a update. As it would be advantageous for Minelab to manufacture two models based on a single chassis/board.
bing

 

[Anonymous]

Cody,
I respectfully disagree with what you are saying. Referring to the Minelab 5,537,041 patent, there is a discussion about frequency domain and pulse induction machines. The patent then goes on to say "The subject of this invention is a pulsed, discriminating time domain conducting metal detection apparatus utilising rectangular transmitted pulses. The term time domain implies that the method employed by the invention is best analyzed in terms of the temporal evolution of signals, just as frequency domain devices are best analysed in terms of frequency and phase signals." Here we see the great distinction between frequency and time domain techniques.
By looking at the waveforms covered by the patent one will see that there is nothing in the analysis of the received signal that relates to frequency or phase. All of the analysis is done by examining the time (temporal) domain waveform.
Looking forward to your comments.
Regards,
Glenn

 

[Anonymous]

Bob,
Refer to my comments to Cody above. I think that this explains why Minelab does not get hung up on the 28 frequencies. The reason is that it is a time domain not frequency domain detector.
HH,
Glenn

 

[Anonymous]

The beauty of any of the computerized detectors today - Minelab, Whites, Garrett, etc. - is that they can be retooled and made to function entireley differently through software.
Minelab has <STRONG>NOT</STRONG> has you state "<EM>simply taken an Explorer board and disabled features</EM>". The unit uses FBS technology but much of the rest of the internals are different between the Quattro and Explorer. You want to see the boards laying next to each other to satisfy your curiousity as to there being any difference . . . . . . do you have the expertise to tell what a different IC chip means as to the final product?
Your statement as to the Explorer being ready for an upgrade now that the Quattro is out also makes little sense. There are options on the Explorer that still stand out above the Quattro and there are new features on the Quattro that are not on the Explorer. Why would you possibly want to take make a common circuit board and apparently do what you said they did initially; i.e., simply disable features on an Explorer board to get a Quattro?
The Quattro does operate on 28 frequencies like the Explorer with the lower and upper points fixed; i.e., 1.5 kHz and 100 kHz. The 26 in between these points vary slightly from channel to channel (that's what is being selected when you see the Quattro cycle from 10% to 100%). When the optimal "set" is selected based on ground conditions and outside interfernece, you are ready to hunt.
As far as the technical details of how BBS and FBS works, I personnaly think that trying to delve into that subject - with much of it still proprietary - would simply result in more confusion and pointless exchanges. I have discussed this very topic with the engineers at Minelab extensively over the years and while I have a rudimentary understanding of the technology, even with an engineering background, I do not profess to be an expert in any fashion. Bruce Candy - the inventor of BBS, FBS, MPS, etc. - is someone that thinks on a far different plane that 99.9% of us do. To be able to hear of a problem with current detector technology and then develop an entireley new solution in a short period of time - with much of it done in his head - is something I can not even imagine attempting.
Andy Sabisch

 

[Anonymous]

I cannot disagree but don't understand the problem. It seems to me that patents would be in just as they are presented in time domain and pulse induction. However to market the detector as PI would be incorrect becasue it is not a true PI detector. The increase in the power in the harmonics by using a rectangular wave form and sampling the decay of induced eddy currents in the target is fundamental to VLF technology and is properly in the frequency domain. To discuss the operation in frequency domain that is familar and simpler to discuss also seems like a good idea.
Pule induction means someting completely different to most users and the hobby.
Tell me what the problem is with analysis in frequency domain instead of time domain. We can covert back and forth between the two but the physics are the same. Instead of a sine wave with limited power in the harmonics we have a pulse with increased usable power in the harmonics. Eddy current induction is still the method of ID.
Where am I going wrong?
HH, Cody

 

[Anonymous]

I agree with you but only to some degree. The discussions seem productive to me and do no harm for the most part. I would in fact say that they spark interest and some lively discussions.
As an example, you see that both of us took this as an opportunity to correct ideas about the Quatro and to squash the idea that the Explorer is going down the tubes.
Anyhow, I see all of this as just normal interest and coffee room talk by people that enjoy the hobby. I would expect technicains and engineers to have more than a basic interest in how the circuits operate.
I do think someone, an engineer such as yourself or one of the others, needs to host a forum for the folks that are interested at that level. My only concern is that in depth discussion may be confusing and create harm on a general discussion form. I think that is your point and I agree.
HH, Cody

 

[Anonymous]

Cody,
I really do not want to "beat a dead horse". All I am trying to say is that Minelab claims that it uses a "time domain" detection process and distinguishes itself from either "frequency domain" or "pulse induction" detectors. I think that we are trying to "force a square peg into a round hole" when we try to explain the behavior of "time domain" process in terms of transmitted and recieved frequencies components.
Still friends?
Glenn

 

[Anonymous]

Glenn, I am very interested in what you are saying. The same thing bothered me when I looked at the patents. I think if you drive a coil with a square wave and what I saw was a modified PI type detector. However, when I leaned in that direction I was chastised. I let that go so I would not cause confusion by saying a lot about it.
In no way is what you are saying a problem to me. I am very interested because I think you are correct but wonder about all the fuss over 17, 28, 2, 98 and infinite frequencies. I started to explain the machine from frequency domain to avoid the issues with time domain. It is also in line with the DFX which more people understand. When I looked at the patents I wondered if I was looking at the correct ones from all that I had heard and been told.
Believe me, I appreciate your comments and don't at all consider anyone on the forums as anything less than folks that love the hobby that I would enjoy detecting with. If I could I would enjoy coffee with you and hearing what you have to say any day.
I agree that there is no reason to beat a dead horse even if I have beat a few in my days. The interest is real and I hope to alwasy keep the door to learning open.
HH, Cody

 

[Anonymous]

Cody,
Thanks for your response. I am particularly in tune with (and think in terms of) time domain analysis because much of my career has been involved with computer simulation of circuit designs in the switch mode power supply industry. Simulation is done using "time domain" and "state space" techniques.
You will also note the question raised below by Bob about why Minelabs does not say much about the 28 frequencies in their advertising. My feel is that the 28 frequencies are not really fundamental to the operation of the machine. Even though the response of the various targets in the ground do depend upon the stimulation frequency, you cover all the bases by using a well shaped series of retangular pulses with controlled rise and fall times. You do not waste transmission energy at the excessively lower and higher frequencies.
HH,
Glenn

 

[Anonymous]

Am I correct then that we are looking at the slope of the decay referenced to the TX pulse for target identification?
HH, Cody

 

[Anonymous]

[No message]

 

[Anonymous]

You accusation that I am spreading misinformation is an affront and totally uncalled for. What? Did somebody send you a detector at the wrong time of the year again, and again, and again?
If you had bothered to understand my post, I merely posed two scenarios to the proposition that the innards of the quattro are new and improved. What is the harm in that? Is there suddenly a monopoly in thinking here? This is a forum, a place to exchange ideas.
Your lofty perch as an engineer is admirable, but us mortals are not entirely clueless of electronics manufacturing and design. I doubt that in your years of experience that you could on sight describe the function of an IC that has been fabbed specifically to contain proprietory software. That is the point eh? Software is fabbed into chips to keep the IP secure.
You said -
"Your statement as to the Explorer being ready for an upgrade now that the Quattro is out also makes little sense."
and in the same breath -
"The beauty of any of the computerized detectors today - Minelab, Whites, Garrett, etc. - is that they can be retooled and made to function entireley differently through software."
This actually supports my proposition of an update if indeed the quattro is new FBS platform from the ground up. It takes a simple flash of software to turn a board from an EX to a quattro, plus or minus a few buttons. An update does not necessarily mean an EX3 more like EXv2.1 which does not necessarily need to be announced.
All this is ofcourse mere speculation, an excercise of the mind. But then you barge in here and accuse me of misinformation! Ugh! You really burn me up.
bing