Equinox Software Update 3.0...

[Chase Goldman]

30 minutes ago, GB_Amateur said:

The only plus I saw (admittedly very short time to be testing) for 4 kHz was that it was pretty quiet at gain=24 whereas MF had to be turned down to 22 for similar near quiet operation. 

Chuck - would be interested in comparisons of 4khz to 5khz (in addition to your MF comparisons).  For example, whether you observed 4khz could also be run at higher sensitivity vs.5 kHz (similar to your MF observation).  Just trying to ascertain whether ML is doing something different with the 4 kHz SF WRT signal processing and noise immunity vs. the other SF modes.  Thanks.

[GB_Amateur]

12 minutes ago, Chase Goldman said:

Chuck - would be interested in comparisons of 4khz to 5khz (in addition to your MF comparisons).

Good idea.  Will do.  My back yard is pretty EMI noisy, noisier than any of my current parks.  Thus it's a pretty good stress test for EMI.  Mineralization-wise it's moderate (2-3 bars on both GB Pro and F75) which I think is typical for my area.

[cudamark]

I wonder if substituting 4khz (or even 3khz) in place of the 5khz in multi would be beneficial. Does that leave some sort of khz gap making it undesirable? How far can you stretch a khz gap before it starts to "break down" the advantage of multi? If too many frequencies dilute the signal too much, then fewer frequencies should be better, right? Why wouldn't a 3khz, 20khz, and a 60khz combo not be better? Too big a span between them? Sorry, I'm not an electronics engineer, just a button pusher! 😁

[cudamark]

16 hours ago, cjc said:

Hope they got his good side--guess they ran out of bearded guys.  

I had really hoped that 4kHz would be in the multi mix hence the stability gains by way of balance in the higher weighted modes ie P2.   Jury still out would like to hear from some salt water hunters on this. Never liked how the big coil performed in salt--same with the CTX's even bigger processor.  cjc 

I use the 12X15" coil almost exclusively at the beach....both in the water, wet sand, and dry sand. I love it! Still very sensitive to tiny targets, very stable using the proper mode and settings, and great for ground coverage. The only thing I've found that goes deeper (and only by a slim margin) is the Excalibur with the 15" round coil (both WOT and NEL Attack) The Excal will miss small targets, however, in comparison to the Nox.

[mn90403]

I have gone out with the 15 two nights this week and it performs better now than it did before IMHO.  I always called the 15" coil finicky.  By this I meant it was harder to make it quiet and the iffy signals were a challenge.  I KNOW the sounds of the 11" coil and if I used the same settings with the 15" it was a different animal.  I avoided using it on the beach because of the transitions.  I would much preferred using the 17" CTX with hipstick on the beach.  

Now it is much more stable.  I found some targets that I need to take a picture of but they range from very small to larger rings (none gold) on beaches that don't have patches.  It now is a tossup between the 11" and the 15" on walking the beach which one to use.  I did get into the water and shallow waves with the 15 and while stable it was going to drag me away or break the ears so the 11 would be better there.

Now I am wondering about the V 3.0 and the 6" coil and Gold Mode.  I'm thinking about taking a night trip for gold again and using the Equinox rather than the Xcoil most of the trip.

Mitchel

[GB_Amateur]

2 hours ago, cudamark said:

I wonder if substituting 4khz (or even 3khz) in place of the 5khz

People who have used oscilloscopes to deduce the frequencies in Multi indicate 5 kHz isn't used, either.  (See Chase's post above.)

[GB_Amateur]

Just a quick report on my test garden results today.  I investigated pseudo depth limit on a 5 inch deep (in ground) 95% copper Memorial USA 1 cent 'penny' in 2-3 bar Fe3O4 dirt (Gold Bug Pro and F75 scales).  11 inch coil in Park 1, recovery speed 5, Iron Bias F2=0, ground balanced and noise cancelled:

MultiFrequency and 5 kHz allowed me to raise the coil 2.5 inches above the ground before losing signal.  4 kHz beat that by 1/2 inch.  Those were all performed with Sensitivity of 20.  (My least unit of measure is 1/2 inch which is also my estimate of uncertaintly.)

I repeated at sensitivity 22 which was a bit quieter for 4 kHz than the others (which were about equally noisy).  Again the MF and 5 kHz were the same -- coil could get 3 inches above ground level before loss.  And again 4 kHz beat those by 1/2 inch.

Previously (reported in this thread this past Monday) I was able to get the sensitivity up to 24 in 4 kHz in my back yard, but not today.

 

[cjc]

21 hours ago, Chase Goldman said:

Clive, most of the "magic" of Multi IQ is likely about how the target signal is processed not what and how many simultaneous individual constituent frequencies are transmitted by the coil.  There is ample evidence from those who have actually measured the individual frequency components being transmtted by the coil for the various Equinox modes, that all four of the. Park and Field modes across the board likely, simply use the two frequencies of 7.8 khz and 39 khz (5 to 1 frequency ratio) combined and transmitted simultaneously (different frequency combos are used for the Beach and Gold Multi IQ modes).  Yet each of those modes has very different responses to high and low conductive targets.  This can only be explained by postulating that the relative magnitudes of the two different transmit frequencies are varied from mode-to-mode and/or different signal processing algorithms are applied to the received target signals from mode-to-mode.  In fact, adding another discrete frequency to the simultaneous frequency mix would likely only degrade performance as transmit power would have to be shared between 3 vice 2 individually and simultaneously transmitted frequency signals, reducing depth performance (a case of where more is not necessarily better).   

That being said, it really appears that 4 khz has something different going on vs. the other five original single frequency settings and that may actually be indicatve of some additional signal processing magic.  Perhaps ML is attempting to optimize a new signal processing algorithm by getting it into the fielded Equinox machines as a massive beta test bed (albeit in a single frequency vice multifrequency application, to start) for potential incorporation into their next genera mtion Multi IQ platform (e.g., a Mu,ti IQ variant of the CTX).  All just hopeful speculation on my part.

I think Minelab just created a lot of consternation and confusion with their infamous "cloud" diagram (below) that implied but never actually confirmed that the 5 original individual single frequency settings of the 800 were also the individually transmitted, simultaneous multifrequency constituents of Multi IQ.  If this were actually true, then that would probably be one of the most craptastic multifrequency detector technology implementations of all time for the reason stated previously regarding power efficiency.  Adding 4 khz would just make the situation worse, as stated above.  Consistent with the sentiment that respected detector engineer Carl Moreland (Geotech) has expressed elsewhere on this board, and as an engineer myself, I am very disappointed that the ML engineering community allowed the marketeers to let that pseudoscience graphic design abomination see the light of day.  Reading more closely, it appears that the advantages of two different Equinox concepts/technologies/capabilities were attempting to be explained that were both rooted in the principle how targets of consisting of metals of different conductivity and magnetic properties respond differently to different transmit frequencies, simultaneous multi-frequency (Multi-IQ) and discrete selectable multifrequency (which ML dubs 5Fx8 on the 800 and 3Fx3 on the 600).  In the former, you can get away with just two or three simultaneously transmitted frequencies to get the desired "frequency spectrum effect" due to signal interference and harmonics when two or more frequencies are mixed (ironically, the principle of a beat frequency oscillator used by early BFO machines).  But to cover the same spectrum "ground" so to speak, using single selectable multifrequency requires a lot more discrete signal frequencies to be able to be transmitted one at a time (ML chose 5 and then eventually 6 for the Equinox 800...wonder if they have to call it 6Fx10, now and what about the 600, is that now 4Fx3.75? ).  These two concepts got smushed together somehow in the graphic below and most everyone got confused as a result (including me, until Carl and others helped me to understand how what ML was showing/implying in this diagram could not represent a practical working simultaneous multifrequency detector).

That's certainly and interesting and informative run-down, Chase.  I had the impression that multi meant multi--but in using the detector had the sens of high and low competing--with small surface targets dominating to produce a "bittyness" to the audio if you were up too high in one of the higher weighted modes (P2, B1...).  The industry is certainly no stranger to "psuedoscience"--I guess they don't expect guys with engineering backgrounds and the wherewithall to conduct proper testing (Carl is certainly a known "debunker") to take them to task.  The modes certainty do each "feel" different and what will stabilize one will make another go berserk.  Of all the machines that Jim and I have looked at--we are still trading notes and trying to get a handle on the EQ.  My take is that sometimes it surprises you with the depth--other times with the lack of it....

I share your next gen CTX dream...but hope it's easier to figure out and tune than the EQ.

cjc

[Chase Goldman]

5 hours ago, cjc said:

I share your next gen CTX dream...but hope it's easier to figure out and tune than the EQ.

If ML indeed comes out with a Multi IQ variant of the CTX, I suspect it will be more intuitive than the Equinox.  ML seems to learn from each iteration and rarely repeats mistakes, so I suspect it will comprise the best of what it's predecessors (the CTX 3030 and the Equinox) have to offer.

I may be overly harsh on that diagram, btw.  I do think it can aid in understanding how simultaneous multiple frequencies create a spectrum that can interact with targets differently than a single transmit frequency on a conceptual basis, I just think that they confused the issue by implying a link between Multi IQ and the 5 individual 800 frequencies when none actually exists.

[Smithobx]

On 8/12/2020 at 10:10 PM, Chase Goldman said:

confusion with their infamous "cloud" diagram (below) that implied but never actually confirmed that the 5 original individual single frequency settings of the 800 were also the individually transmitted, simultaneous multifrequency constituents of Multi IQ.  If this were actually true, then that would probably be one of the most craptastic multifrequency detector technology implementations of all time for the reason stated previously regarding power efficiency.  Adding 4 khz would just make the situation worse, as stated above. 

I do not think anyone, other than Minelab, could make that statement as a definitive fact. I say that because on page 100 of the Explorer ll manual titled “Technical Specifications” it states: “Full Band Spectrum. Simultaneous 28 frequency transmission ranging from 1.5 kHz - 100 kHz.”  Unless Minelab is flat out lying (which I doubt) they have had the technology to transmit on up to 28 frequencies SIMULTANEOUSLY for at least 15 years. I don’t think transmitting on 5 or 6 frequencies simultaneously  would be a problem, especially considering Minelab has had an additional 15 years to refine the technology. I think the much maligned cloud illustration means exactly what it implies. This is just my opinion based on the above as I certainly would not wish to confuse opinion with fact.