Jump to content

Recommended Posts

Just an example of where multifrequency can still go. Right now you will hear it said that when a detector uses single frequency, all the power is focused on that one frequency, which can give slightly better results on that frequencies preferred target class over multifrequency. This is because multifrequency spreads the power out over the frequency range, with each frequency therefore running slight less than full power. It is the compromise of running all frequencies versus a single frequency. However, with that single frequency you are focused on a single class of targets, and will do less well on the other frequency ranges than the multifrequency unit.

But it does not have to be that way. That is mostly a function of battery power and the desire to keep power use within tolerable ranges. With new high power battery technology, the next step will be multifrequency where each frequency is optimized and running at full power equivalent to what you get running at a single frequency only. I expect we will see this development in the relatively near future.

I want to emphasize again that Equinox is not the be all end all of multifrequency. In fact CTX has better target id resolution and excellent ferrous handling that is arguably better than the Equinox. From my perspective the Equinox is just a crude proof of concept for Multi-IQ, with more benefits still to come. It should be fairly obvious that everything Minelab knows about FBS and has learned so far about Multi-IQ will be going into the next generation CTX model.

  • Like 4
Link to comment
Share on other sites


25 minutes ago, Steve Herschbach said:

But it does not have to be that way. That is mostly a function of battery power and the desire to keep power use within tolerable ranges. With new high power battery technology, the next step will be multifrequency where each frequency is optimized and running at full power equivalent to what you get running at a single frequency only. I expect we will see this development in the relatively near future.

Good point, Steve,.  One might logically ask that if this is the case, then why not just pump more power into the ground in the single frequency detector case.   That is because we are talking about more effective power management and multiplexing each of the frequency component transmit signals so that peak power demands can be lowered overall - sort of like a time share arrangment.   The other part of the equation is that there is a practical limit (that has already been reached by today's single frequency detectors) that pumping more power in the ground simply results in diminishing returns because of the noise that is generated.  You are getting no depth benefit at that point, in fact you are making things worse,.  This is especially true in mineralized ground where lowering transmit power is necessary to eliminate noise and ground feedback (some detectors like Nox do this automatically in beach mode, while others, like Deus, enable the user to manually reduce transmit power).  This is part of the reason why single frequency detectors have less of a "power" advantages over MF detectors in mineralized soils.  So it is no just a matter of "going to 11" as far as power is concerned, but increasing the power capability across the frequency "spectrum" as something that can improve MF performance vs. SF.  Most of the gains, however, are best leveraged by taking maximum advantage of processing horsepower through use of more sophisticated signal processing programs that can better identify probable junk targets through the tell tale target signal fingerprints of typical junk items.

  • Like 3
Link to comment
Share on other sites

Yes, single frequency is already at the limits of what more power can offer before it is counterproductive. Multifrequency is not, which is why you see that as a sales pitch for single frequency. I do think we are a long way still from what sophisticated signal processing can achieve with multifrequency.

  • Like 3
Link to comment
Share on other sites

So, to return to the original question, those who do not detect in areas where there is moderate to high mineralization/saltwater conditions may not see any benefit from one of the current simultaneous multi frequency detectors, i.e. the Equinox on shallow to medium depth targets like the example kac gave concerning a 6" large cent co-located with iron. That makes sense to me. However, whenever anyone tells me I just don't know what my single frequency detector is really telling me, I just want to throw up. I wish I had soil conditions like that to hunt in.  In my soil conditions that dividing line between a single frequency detector running at high transmit gain versus the Equinox is 3 to 4". Past that depth, absolutely any single frequency detector has zero reliability as far as multiple tone ID or numerical target ID accuracy. Every target past that depth becomes an extremely high conductor or an iron target so the entire low to mid conductor target accuracy is completely gone. So, a single tone beep and dig detector with good ground balance capabilities,  no display,  an 11" DD or so coil and ample transmit/receive power running above 14kHz would do just as well. 

So, I have two choices,  use and learn my single frequency detector's minute nuances and interrogate the target for several seconds (or more) along with do some mental math (do I add or subtract 20 to 40 target ID numbers to what I think the target is and take a chance????). Or, do I use a more appropriate simultaneous multi frequency detector for my soil conditions, spend less time analyzing targets and dig many more quality targets which are accurately identified with appropriate tones and numbers down to at least 11" or more?

I took my G2+ yesterday for a short hunt in an aluminum trash filled local park. I am not a big fan of the discrimination mode on the G2+ because of its tone choices. Basically it is a 2 tone detector in discrimination mode depending on if and where I set the V-Break and iron volume. I basically just wanted to cherry pick copper pennies, dimes and quarters so I set the tone break between low tone and VCO tone pretty high (80), just above zinc pennies and only dug VCO tone targets. I dug so many zinc pennies, 4" deep pull tabs and a couple of US nickels that it was extremely frustrating. I dug plenty of dimes and quarters too but that up averaging is just not fun. I still love the Tek G2+/F19/Time Ranger Pro form factor and since this Tek G2+ was my first really good detector with a display after many years with a Lobo Super Traq, I will never sell it. To be totally truthful, the Garrett AT Gold was my first VLF with a screen but it went bye bye really fast....... (couldn't stand the unadjustable iron audio). The Tek G2+ pistol grip and threshold based all metal mode are just too good. 

But, I am so thankful that the Equinox with all of its great features and obvious faults, came along and revitalized my desire to keep dirt fishing for coins and jewelry after too many years of target ID accuracy misinformation and frustration. I also look forward to using the Garrett Ace Multi-Flex Apex!!!!

 

Jeff

 

  • Like 2
Link to comment
Share on other sites

A very good question,i personally use a selection of both 'fixed' single freq machines and multiple freq as well and also 'selectable' individual freq machines.

Multi frequency machines have some massive advantages like the ability to be used in salt water environments like beach detecting etc and also for high mineral ground conditions,so that is one area that i use such a machine as the Equinox,but i also use the selectable freq Deus and if i am honest that is my preferred option as that covers with the coil options all my main everyday needs.The main reason i use the Deus over say the Equinox is the slightly better coil choice,the HF elliptical i find works exceptionally well  on my roman/saxon sites.

Then i also use specific 'single' frequency' machine for site specific use,these are machines like the Nexus MP that i use,single freq at a time,and can be changed like the Xterra by changing the coils over to a more suitable freq for the job in hand,the main reason i use these specific single freq machines is that they have the ability to use higher power into the coils like the Nautilus detectors can but more so in the case of the Nexus MP i think i am right in saying the voltage is upto just over 100 volts,this is what makes it special and the main reason i use it as do others for its ability when coupled with a larger coil/s to go into the depth range of say a Pulse machine but with discrimination which a PI machine in theory does not have or certainly not in the same league.Of course this type of machine is not your every day use machine and more specific use,but it does show just how in some situations that a single freq VLF machine can excel as it has no competition in theory.

So yes i do use a selection of both single freq and also multiple freq as i take advantage of specific coil options that some machines offer over others,no single freq or multiple freq detector/coil combination does it all,this is why personally i have a wide selection of detectors and coils,so i can mix and match in what i consider the best combination for that days detecting scenario and the ground conditions.

Todays multi freq detectors with say a 11'' DD are designed as a happy all round medium combination and for most cases should be all you really need,but also in some specific cases a single freq machine can excel and increase the odds in your favour.

 

 

Link to comment
Share on other sites

5 minutes ago, phrunt said:

I have tried various recovery speeds, I honestly didn't notice any difference going lower other than the audio changed, I didn't find any difference in finds so I just went back to defaults.  I know technically slow recovery speeds should be deeper and fast better in trash, I don't have to worry so much about the trash in most of my spots and the depth didn't really seem to make a difference when I went lower.   I tried lowering on deep targets to see if they improved at all no difference. Maybe more beneficial in worse soils I guess or I've just not found a target that's at the exact right depth for it to make a difference who knows.  I'll keep experimenting though, I like experimenting 🙂   I can see faster recovery speeds being beneficial in trashy areas so I'll play more with that.  Same with the Vanquish, I found no benefit using Relic mode (deepest mode) to find deeper targets, Jewellery mode did the trick just fine.

It seems like a lot of things metal detecting, what works in one location doesn't in another so people always have to work out what works best for their locations.

If the vanquish is doing better then the nox you   can't argue with results. If it handles Emi  better then nox then that could make a big difference on targets   . The coils could    also be  better then nox for emi.  I Would like to see you with the apex in your coin fields.If I was in charge of Garrett I would send you one.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...