Sens Setting For Deep Coin Squeakers…

[GB_Amateur]

5 hours ago, Chase Goldman said:

...Iron bias seems to be there because ML figured out they could do it with Multi IQ (note that iron bias is not even present when operating in single frequency) but did not at least articulate the down side.  It seems to be a setting that has no benefit other than to prevent SOME falsing but with a lot of down side IMO.  I am not even sure having it set at low values is beneficial, so I agree with you it is IRON BIAS = 0 for me too.  It is definitely something to be aware of in Park 1 AND the Beach and Gold modes.

I never heard of iron bias before the Equinox, but I also never paid much attention to BBS and FBS detectors, either (and still don't).  In my defense ?, I don't remember those detectors being talked about much on this website before the Equinox was introduced, and this is the only website I follow.  Is IB strictly a Minelab thing?  Something is telling me it also is a feature on the XP Deus (you'll confirm or deny that, I'm sure), but if so, did XP just get the idea from earlier minelab VLF's?

[Happa54]

3 hours ago, Tiftaaft said:

Great thread!.  Thanks everyone for taking the time to detail your personal experience and results with the Equinox.  Hap, I bet you fidn't know the Hornets nest you were poking when you posted your first question... haha (and I mean that in a good way).  

My experience has been very similar to Bryan's here in the Pacific NW, though my finds have not been as impressive.  I have been running my 800 with the 15" (I agree with Bryan, it is a beast!!) In field 2, 50 tone, all tones (with a custom disc similar to Bryan's for really noisy areas), recovery 4 and IB-2 (though I have used IB-0 a fair amount).  I have a 30's-40's park near my work that I am currently meticulously grinding and I am pulling some nice finds at the 8-10" range.  I am starting to hear the nuance between a shallow target tone and a deeper target tone and probably more importantly understanding the "shape" of the target based on the tone.  I start getting excited when I hear that mellow round high tone and my depth meter is at 4 bars plus.  The WLH/SLQ combo was 9.5" at least, and was solid tone from one direction, but I had to work for it (note the "ring" on the back of the WLH where the SLQ was resting until I recovered it).  The hunt with the Ike was 2 days ago during a lunch break, 45 minute hunt.  All the coins pictured were 7"+, except the Ike that was about 6" (and singing solidly at 37-38).

I gravitated to field 2, but will probably cover the area again in park 1 or field 1 as reference to the discussion about the differences in the machine programming between 1 and 2 settings.  And I will also kick it down to IB0 to see what I have missed by making some iron co located targets.  

Thanks again everyone for the masters class of information above.  

Tim

Well Tim... I guess I'll have to poke around in another hornet's nest in another thread...LOL. 

I highlighted in red your response re "target shape based on tone". This is something I'm hearing for the first time. I more or less know the size of my targets through coil manipulation and pinpoint, but the shape of the target based on tone? I'm not there yet with the Nox. I need to know more about this technique. 

Thank you for mentioning it. 

[Tom Slick]

Iron Bias is basically the same thing as White's "Bottle Cap Reject". It's been on a number of White's detectors, V3i, VX3, DFX, etc. An adjustment to help make sure bottle caps (iron) registered as such and not a coin. Of course now, many bottle caps are actually an iron /alloy making it more difficult to disc out without missing good targets also. DD coils don't help in that regard. In the past, most detectors used concentric coils which are better at discrimination but now most manufactures use DD coils as standard equipment. Each have their advantages. 

[Steve Herschbach]

4 hours ago, GB_Amateur said:

I never heard of iron bias before the Equinox, but I also never paid much attention to BBS and FBS detectors, either (and still don't).  In my defense ?, I don't remember those detectors being talked about much on this website before the Equinox was introduced, and this is the only website I follow.  Is IB strictly a Minelab thing?  Something is telling me it also is a feature on the XP Deus (you'll confirm or deny that, I'm sure), but if so, did XP just get the idea from earlier minelab VLF's?

What Tom just said above. From the White's DFX User Guide:

White’s DFX Bottlecap Reject

Adjusts how strongly the instrument rejects or breaks up on iron. Most starting programs use the minimum setting. As larger numbers are selected, more bias rejection against iron occurs.

The advantage of higher BOTTLECAP REJECT settings is that in high trash areas more decisive iron rejection occurs. Trash becomes easier to identify by the broken sounds they produce.

The disadvantage of a high Bottlecap Rejection setting is if an iron target is close to a good metal, the high degree of bias against iron may cause the detector to cancel both responses. Another disadvantage is that all targets, iron and non-iron, tend to start sounding more broken at high levels of BOTTLECAP REJECT. The operator needs to fine tune BOTTLECAP REJECT according to their preferences and the conditions being searched.

Some ground conditions make it difficult for the instrument to recognize iron. BOTTLECAP REJECT allows compensation for these areas.

[Tiftaaft]

4 hours ago, Happa54 said:

 

I highlighted in red your response re "target shape based on tone". This is something I'm hearing for the first time. I more or less know the size of my targets through coil manipulation and pinpoint, but the shape of the target based on tone? I'm not there yet with the Nox. I need to know more about this technique. 

I am still getting comfortable with it myself... but it is all about coil hours on the ground for me.  The more I hunt the better I understand the Equinox "vocabulary".  Tim.

[Chase Goldman]

6 hours ago, GB_Amateur said:

Something is telling me it also is a feature on the XP Deus (you'll confirm or deny that, I'm sure), but if so, did XP just get the idea from earlier minelab VLF's?

It is similar to the Deus silencer feature and I have also turned that off on my Deus based on Tn Sharpshooter videos demonstrating how silencer can cause masking and one way signals of non ferrous targets near ferrous objects.

[Happa54]

Hey Everyone…

I had to dig this one up and bring it up for discussion…again.

I have hundreds more hours on the Nox since I started this post over a year ago.

Out this evening with my Etrac and Explorer buddies who I refer to as the “Silver Slayers”.

I was not swinging my Nox due to a bad back but I tagged along to get out for fresh air and to see if I could find things on the surface at the dirt field.

For some reason, the subject of high vs low sensitivity came up. They both told me that they run their sens slightly above the halfway point on the meter. Their machines max out at 30 vs 25 on my Nox. They have their sens settings at 18. Their recovery speeds are set on default.

This took me by surprise that they don’t run their machines hot, but yet they dig to depths of 9” and 11”. I asked them to explain. Their answer…..”At high sens the shallow targets drown out the deep coins therefore you don’t hear them…at the lower sens settings, the shallow targets allow the deeper targets to be heard.”

Now I wonder….is there a difference in the technology between multi IQ and FBS that makes this happen?  I have adjusted my sens on numerous occasions while waggling over targets. If I lower my sens, I lose the target. If I run the sens up near max, I can hear the deep targets.

I do very well with my Nox but I cannot keep up with these guys. Their respective silver, wheat and nik counts are 2 to 1 over mine…every time.

I’d like to hear a little more feedback on this subject, if you don’t mind.

 

[GB_Amateur]

10 hours ago, Happa54 said:

Their answer…..”At high sens the shallow targets drown out the deep coins therefore you don’t hear them…at the lower sens settings, the shallow targets allow the deeper targets to be heard.”

For one thing, you said they are operating ETrac and Explorer (Minelab simultaneous multifrequencies, yes).  I've never tried either one.  So maybe for those detectors what they say is true in general -- I guess we need to hear from other users of those.

For a long time I've felt (transalation:  gotten the impression but far from convinced) that higher gain amplifies iron more than non-ferrous.  That feeling comes from other detectors as well as the Eqx.  When the Eqx first came out there were some complaints that it didn't amplify nearby and large targets much compared to more distant and smaller ones.  Well, it certainly doesn't have an overload.  The sound amplitude is greater for large/nearby targets, but it does seem to be a more subtle effect than at least some other detectors.  Obviously it has no minimally filtered (what many other companies call "all metal") mode which is the usual best way to hear audio amplitude proportional signals.

As far as sensitivity, that really does seem to be one of those things that a) doesn't respond like other electronics such as the effect of turning up the volume on a radio, b) is background sensitive (EMI, ground, trash), and c) has a lot of user-personal preference.  In my case I've only recently started running sensitivity of 22 as my standard.  Previously my standard was 20.  I do think the most recent upgrade (6+ months ago now) allowed me to do that by handling EMI better.  I did well park hunting with sensitivity of 18, but my parks seem to have a fair number of old coins that aren't super deep.  Definitely for air testing and in low mineral, not trashy ground I can get deeper with higher gain.

 

[Chase Goldman]

10 hours ago, Happa54 said:

Hey Everyone…

I had to dig this one up and bring it up for discussion…again.

I have hundreds more hours on the Nox since I started this post over a year ago.

Out this evening with my Etrac and Explorer buddies who I refer to as the “Silver Slayers”.

I was not swinging my Nox due to a bad back but I tagged along to get out for fresh air and to see if I could find things on the surface at the dirt field.

For some reason, the subject of high vs low sensitivity came up. They both told me that they run their sens slightly above the halfway point on the meter. Their machines max out at 30 vs 25 on my Nox. They have their sens settings at 18. Their recovery speeds are set on default.

This took me by surprise that they don’t run their machines hot, but yet they dig to depths of 9” and 11”. I asked them to explain. Their answer…..”At high sens the shallow targets drown out the deep coins therefore you don’t hear them…at the lower sens settings, the shallow targets allow the deeper targets to be heard.”

Now I wonder….is there a difference in the technology between multi IQ and FBS that makes this happen?  I have adjusted my sens on numerous occasions while waggling over targets. If I lower my sens, I lose the target. If I run the sens up near max, I can hear the deep targets.

I do very well with my Nox but I cannot keep up with these guys. Their respective silver, wheat and nik counts are 2 to 1 over mine…every time.

I’d like to hear a little more feedback on this subject, if you don’t mind.

 

There are a mixture of things going on here.  I am not an FBS expert, but I know enough to be dangerous based on limited swing time with a CTX and sitting in on Andy Sabisch's FBS bootcamp presentation (in other words: I know what I don't kinow about FBS/FBS2 detectors).

The FBS and Multi IQ multifrequency processes are fundamentally different so that makes it difficult (impossible?) to do an apple to apple comparison based on settings alone.  I am not going to go into this in too much depth but it is discussed at a high level in the Minelab Multi IQ tutorial series that was put out during the Equinox initial release and was consolidated by Steve H. here:

https://www.detectorprospector.com/metal-detecting/minelab-multi-iq-technology-details-explained.htm

There is a great rackout of BBS/FBS Machines vs. Equinox by Steve H.here:

Both of the above links are contained in Steve's excellent Minelab Equinox Essential Information thread.

Regarding the FBS machines, they have very sophisticated discrimination implementation and an AUTO sensitivity setting (which I know very little about).  You can discriminate on both conductivity and "ferrous" ID on a 2-dimensional basis.  FBS is very computationally intensive as far as signal processing is concerned.  That combined with likely a slower processor (vs. Equinox) make for a lower recovery speed vs. Equinox and also FBS/FBS2 is weighted towards lower frequencies/higher conductors (and correspondingly weaker on gold) vs. Multi IQ which is comparatively more balanced overall (even when considering the Multi IQ low frequency weighted modes) and also, unlike FBS, multiple Multi IQ profiles exist on Equinox to enable Equinox to be set up to favor different target conductivity ranges (high vs. mid conductors and gold) and environments (park with modern/aluminum junk vs. field with iron junk vs. beach).

All this being said, I am somewhat skeptical on what your silver slayer friends are saying about lowering sensitivity to get maximum depth by keeping shallower targets from overloading their machines because it sounds like something that one NEVER gets in metal detecting - "the free lunch".  Metal detecting is all about trade offs.  You can filter out iron with disc or iron bias but you risk missing low conductive keepers or masked higher conductors.  You can notch out pull tabs because you are hunting around a common bonfire area, so you risk not finding that gold ring, but clean up on silver and clad.I have often lowered sensitivity in thick iron situations, to enable me to "see" or "sift" for shallower keepers that would otherwise be masked by strong iron signals (deep or shallow) overloading the coil.  Notice that I said, "shallower keepers" because I am willing to trade depth to recover masked keepers that have been sitting there for decades because they were missed by slower detectors that wouldn't stand a chance under those conditions regardless of their sensitivity setting.  I have never heard of maximizing depth by lowering sensitivity, alone.

Although they are recovering high conductors at significant depths with these lower sensitivity settings, I suspect that perhaps there is significant sensitivity headroom available on the CTX/eTrac vs.the Equinox. Note that if the setting ranges were perfectly linear and scaled equivalently between the machines, then an 18 on a CTX would be equivalent to a 15 on Equinox.  Not a setting I would use for max depth.  Note also On the CTX the default manual sensitivity setting is 22 which would be the equivalent of 18 on the Equinox (not the same as the Equinox's 20 default setting) so that lends more credence to the "increased sensitivity headroom" vs. Equinox argument.  At the very least, you can see that comparing the sensitivity settings between the two machines to be a tricky proposition at best.

For max depth I would set the Equinox up on the highest stable setting (i.e., one notch below where noise affects a neutral coil).  Equinox is all about maximizing signal to noise ratio.  Settings that maximize the signal to the extent practical without raising the noise floor - sensitivity increases the signal to a point, but with too much sensitivity you introduce instability in the form of random signal noise.  I start with the default and move it up or down from there.  You can further reduce noise (which is not just EMI but also ground noise and junk target "noise") by obviously running a NOISE CANCEL which I do before I set sensitivity (noise cancel appears to be done at a preset normalized sensitivity setting that is independent of the sensitivity setting of the machine, so you don't need to set your sensitivity to "max" to do a noise cancel); doing the appropriate ground balance, setting sensitivity "on the edge" unless I am "sifting" through junk (as described above), the setting the appropriate recovery speed (lower recovery speeds can result in more ground noise) and iron bias as desired.  I don't use notches and prefer to run with the default disc setups or run with the horseshoe button eliminating all disc.

All of this is a very long winded way of saying 1) that they may be getting maximum depth for the site conditions, but their ultimate depth could be greater in a situation where the they could run with a higher sensitivity and 2) their default sensitivity setting is lower compared Equinox so even though a setting of 18 seems like they would be hunting with a 16 sensitivity on Equinox all things being equal - the fact is all things are not equal because their default sensitivity setting is lower on the scale vs. the Equinox default setting (i.e., the "22" default on CTX "appears" to be a equivalent to an 18 setting on the Equinox scale, yet the Equinox uses an actual default of 20).  I would take what your silver slayer friends are saying with a grain of salt and recognize that what they are doing doesn't necessarily translate directly to the Equinox.  It is dangerous enough to simply use someone else's favorite settings on Equinox without a basic understanding of what the settings do (a typical newbie mistake).  Being experienced with the Equinox you are not subject to that issue, but things get even more dicey when you try to translate settings from another model detector to your machine even if they are both Minelab multi frequency detectors because that is about where the similarity ends.

[Happa54]

Thanks for your comments Phrunt, GB and Chase.

The technical aspects, nuances and theories of these machines are way beyond my comprehension. So I'll just leave it alone. 

The successes with my buddies is mind blowing as I watch them take in high numbers of silver, wheats, indians, jewelry and relics each and every time I hunt with them. When I hunt solo, I don't give it a thought because I'm inside my own head. When I hunt with them, I get somewhat intimidated because I trail so far behind them on good finds. These guys are just that good and extremely tuned into their respective machines. 

I have 2.5 solid years on the Nox and they have a dozen years on theirs. I guess I can't expect to be at their level of detecting. 

However, from the standpoint of mid sensitivity levels on their machines for deep squeakers, all I can say is, you need to see it for yourself. There is something special about FBS detectors. 

HH