Minelab responds to sensitivity setting question on Explorer and E-TRAC

I e-mailed the Minelab USA customer service and asked about the sensitivity setting. Here is the Minelab reply. This clears it up for me.
Jim
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Jim,
I received your question (below) and sent it on to the engineering team for an official response. I unfortunately have been traveling and am late in responding. Below is the answer direct from the engineering team in Australia.
Increasing the Sensitivity setting on both the Explorer and E-TRAC detectors does not increase the transmit power sent to the coil and the magnetic field into the ground.

The Sensitivity control adjusts the gain of the received signals from the coil. This is not a simple one stage electronics hardware amplification step as the analogue receive signals are converted into multiple digital parameters and analyzed by software within the detector's micro-controller.

Further information about adjusting the Sensitivity setting on these detectors for better performance will be provided in a forthcoming Minelab Treasure Talk blog post.

Jim I hope this satisfactorily answers your question. As mentioned there will be a Treasure Talk blog dedicated to setting these detectors for optimal performance that not everyone takes advantage of.
I hope this helps,
Best regards,

So the sensitivity setting adjusts the gain (plus or minus) from the receive response that you get COMING BACK from the coil.----Depending on adjustment, it can have the "appearance" of the detector detecting deeper (or shallower) on targets.-----When in actuality, the transmit "output" is always the same (non-adjustable).-----That is always the way I have understood it and it looks like that is the explanation Minelab gave also.------------Ohkeee---Two further comments/questions on the Explorers/Etracs.---------(1) The ( seperate from sensitivity control) "gain" feature/control--accessed thru the menu--is also an important setting.----It controls the amplification (+ or -) of the AUDIO coming back from the coil "responses"---amplifying--or not amplifying (audio wise) target responses.----Right?-----------(2) The "deep" feature (again accessed thru the menu)--can be either turned on or off--and is also a feature to provide more "depth" on the Explorer/Etrac (or so they say).----I've always thought of it as "deep on" as a sort of duplication & a feature not really needed when you have high (as possible) adjusted gain and sensitivity settings.----In these cases, I haven't noticed any added benefit in deep "on".-----Maybe there would be if you were using lower gain & sensitivity settings?---Doubt it though! (grin).------The great thing about the Explorers & Etracs has always been is that there are SO MANY ways you can set them up and still get excellent results.------I've owned/used them all from the old XS thru the Etrac and I'm still learning the machine(s)---made some great finds with all of them.-------Well, the above is just "my take" (JMHO) on all this and I'm certainly no expert.-----I do know one thing for sure---I have fun--a blast--hunting with the Minelabs!----------Del

I would think there are very few if any detectors that actually have user
interface to adjust the transmit.
In my limited understanding of VLF electronics, the transmit has to be
setup to provide a balance so there is electro-magnetic force or energy
always going on.
Then any metallic or even ground minerals that disturbs this energy, it is
registered and provides a differential from that standard.
So in my limited understanding, if the above is somewhere close to correct,
if an adjustment was provided, it would upset this "standard".
So if even the receive part of the equation was adjusted then there would
be the same problem.

Perhaps the Nautilus allows for Transmit power to be adjusted?

There may be something FT could do in software with the
F75 and T2 in regards to the new boost process.

I have had the idea and it could be wrong that the only
adjustments allowed by the user on almost all detectors
is "after the fact", that is something to do with how the
signal is used within the confines of amplifying in the receiver.

Maybe not quite this simple but still not anything where the
transmit or receive, going on in the coil is adjusted.

My advice try both ways and see what works best for you in your neck of the woods..

Minelabs answer only adds to the debate...

I drove professonally at speeds of up to 120 miles plus as the speedometer was buried in my job and never had an accident in 30 years of service to the Commonwealth of Penna. and basically learned thru on the job training.
However could I overhaul a motor or for that matter know anything but the basics of car maintenance and hunted with the best of them but couldn't tell you diddly about the internals of the unit I was using except the basics related to me in the manual.
In essence metal detecting is not rocket science so get down to the basics and lets smell the roses as this is not an electronics class but a metal detecting forum...

Well now Dan---thanks for the "scolding" to all of us "would be/wanna be" techies!---we needed dat--- laf (I'm kiddin ya)-----Hey, didn't you ever want to know what made that vehicle you were driving go 120 mph as opposed to say 70 or 80?--------Seriously---I think it behooves all of us to have a little in depth knowledge about the make up of any individual detector as well as the features/settings and the "cause & effect" of these things in a detector to get the (very) most out of them.------You're right--this is a m.d.ing forum, not about rocket science (although we do have a rocket scientist--or like--on here). grin-------I just think there is a higher level of (in depth) knowledge afforded on this forum by a BUNCH of great guys than there is on many other forums.-----Even at my age--I STILL want to learn as much as I can about the equip., detectors AND hunting in general.---------Del



Edited 1 time(s). Last edit at 06/02/2011 10:53PM by D&P-OR.

Great info, GreyGhost -- thanks for getting that.

Can someone please give a link when that article they refer to is placed on the "treasure talk" blog? That's not one I am familiar with, but I SURE don't want to miss that post -- sounds like it will be a MUST read...

Steve

Thanks for that confirmation. I was quite certain (99%).....and it does put it to bed.

As for the Nautilus........yes.......I think this is the only detector on the market that the user can change the transmit power.

The 'deep' feature on the ML's allows for more 'snapshot' // 'samplings' ...... is a bit slower to process....... and can only be effectively utilized in low-trash sites/areas.

D&P-OR Wrote:
-------------------------------------------------------
> Well now Dan---thanks for the "scolding" to all of
> us "would be/wanna be" techies!---we needed
> dat--- laf (I'm kiddin ya)-----Hey, didn't you
> ever want to know what made that vehicle you were
> driving go 120 mph as opposed to say 70 or
> 80?--------Seriously---I think it behooves all of
> us to have a little in depth knowledge about the
> make up of any individual detector as well as the
> features/settings and the "cause & effect" of
> these things in a detector to get the (very) most
> out of them.------You're right--this is a m.d.ing
> forum, not about rocket science (although we do
> have a rocket scientist--or like--on here).
> grin-------I just think there is a higher level of
> (in depth) knowledge afforded on this forum by a
> BUNCH of great guys than there is on many other
> forums.-----Even at my age--I STILL want to learn
> as much as I can about the equip., detectors AND
> hunting in general.---------Del

Del
Me too. I hope that I never lose interest in learning., D.

NASA-Tom Wrote:
-------------------------------------------------------
> Thanks for that confirmation. I was quite certain
> (99%).....and it does put it to bed.
>
> As for the Nautilus........yes.......I think this
> is the only detector on the market that the user
> can change the transmit power.
>
> The 'deep' feature on the ML's allows for more
> 'snapshot' // 'samplings' ...... is a bit slower
> to process....... and can only be effectively
> utilized in low-trash sites/areas.

My Deus has three settings for transmit power. Default is level 2. The manual says that the power only has a subtle effect on the device's pure performance with regard to sensitivity. However, it increases the detector's power consumption as well as alter its stability on difficult ground. A lot of the UK guys run level 3 in open fields where there is less iron and run level 1 in the iron-invested, mineralized ground.

Cuniagau

“Never approach a bull from the front, a horse from the rear or a fool from any direction.”

Perhaps so with the Deus, I was referring to the US market.
And I think you are right about transmit doesn't provide much
advantage to the user as far as increasing it.
But I have always wondered if reducing transmit could help
in trashy areas, we probably will never know unless someone
comes along and makes a full variable adjustment for the user.

The White's Eagle Spectrum and perhaps the XLT's have a setting to adjust transmit power. Its a high/low setting.

And the boost feature on the V3.

The boost feature here increase the transmit power by 3 times i think.

Highly useable when gain and sens levels must be lowered to avoid incoming interference from ground or emi as transmit power from your own device does not interfere with your own device.

It has been recommended to me by a someone who has been using explorers and the etrac since they came out to always run in semi-auto (w my etrac). I have paid a lot of attention to the sensitivity and it usually averages in semi-auto around 19. Sometimes it will go up as high as 26 and not very higher than that. Almost every time I've taken it out of semi auto, and raise the sensitivity I will then get a lot of falsing. So I just keep it in semi, and it usually runs really smooth and rarely a problem with emi.

With regards to sensitivity in the V3i... do a air test, then put it in boost especially in the deep silver program. If that isn't a raise in sensitivity, I don't know what is.

Have to agree can't learn enough about this hobby that has kept me busy the last 20 years and when the manufacturer can't give you a positive answer relative which type of sens. is better one begins to wonder.
Actually no technical knowledge but getting the jist of what is being said although imagine it went right over many
heads in the process.
I actually don't think there is a positive answer when you dial in personal settings and ground mineralization of your area and tip of the hat to Minelab for giving us the choice and from reading have come to the conclusion many excell either way so do act accordingly and do what works best for you.

I'll be looking for the blog