Infinium threshold setting

[cymro]

Hi
Is it true that a higher threshold setting on the Infinium LS increases depth? I am basing this question on some examples posted showing air tests, which appear to be affected by the threshold setting. If this is so, what is the maximum setting forum members recommend, before the threshold hum masks targets.

Dave

 

[ivanll]

Hi
Is it true that a higher threshold setting on the Infinium LS increases depth? I am basing this question on some examples posted showing air tests, which appear to be affected by the threshold setting. If this is so, what is the maximum setting forum members recommend, before the threshold hum masks targets.
Dave

If this was so it would definitely be mentioned by the manufacturer in the Infinium LS Owner's Manual and shown on the instruction Video the fact that it isn't shown or mentioned is closer to the truth.

ivanll

 

[Tom]

Dave- In the hot ground of VA I've noticed a slight increase in depth with a higher threshold, and faint sounding targets on low threshold settings come in loud and clear on higher settings.
I set mine at 4 or 5 for most hunting but the higher it is, the more annoying it can be.

 

[Fishers Ghost]

I tend to agree with Tom,
A setting of 4 or 5 seems to be fine(for my hearing) but the sound of weak signals becomes shorter and sharper as the threshold is cranked up.
The threshold of the infinium will not mask weak sigs because the target signal rides on the threshold tone and so will always be higher than the threshold but if you turn the threshold down far enough the target signal has to be stronger to get back above the zero signal point into the audible range.
The best thing to do is to experiment a bit and decide for yourself how much threshold tone you can stand.
get a target that gives a very weak signal (as a bench test) with the threshold set at just audible and then turn the threshold up to around max without going into the frequency set position and test the target again, I am sure you will hear the signal will stand out more above the threshold.

The threshold of most VLF detectors is different to the infinium.
For example:
with a vlf if you set the threshold to zero (just audible) volts and then apply a target signal of 4 volts there will be an increase of 4 volts to the threshold and you will hear the target clearly, but if you set a threshold sig of 4 volts (very loud) and apply your 4 volt target signal then you will not hear the target.

The target signal from a vlf is just an increase in the threshold level but in the Infinium the target signal is separate from, but riding on, the threshold.

Not sure if this makes any sense, I know what I am trying to say but I am not certain that I have put it together correctly.

 

[Cupajo]

Makes perfect sense to me Friend.

Many Thanks,

CJ

 

[cymro]

Thanks Tom and Fishers Ghost your posts are very helpful.

Dave

 

[lucky 1]

Hi Tom, I herd some where that a guy sets his thresh-hold pretty high and then adjusts it with his head phones. said that it picked up better on faint signals and was easier on the ears. May be, never used it myself.


lucky 1

 

[bearkat4160]

Even though it isnt mentioned in the owners manual....too many people have reported better depth at higher threshold. I for one usually hunt on 4-5. If I get a slight blip I will turn it up to 8 and the signal will pop more. If I set it on 1 for the same target, it will produce no-signal.

I refer to it as more of a sensitivity and threshold knob. It is more sensitive and gets better response from deep/smaller targets when set at 5 for average hunts.

I set my GTI 2500 on some very different settings for prospecting also and it isnt in Garretts manual either for these adjustments in the 2500.

Alan

 

[ivanll]

Hi
Is it true that a higher threshold setting on the Infinium LS increases depth? I am basing this question on some examples posted showing air tests, which appear to be affected by the threshold setting. If this is so, what is the maximum setting forum members recommend, before the threshold hum masks targets.
Dave

There is only one place to ask for such info and that is directly from Garrett.
Ask if the audio circuit in any way controls the sensitivity and depth of the Infinium LS.
If there was any truth to the rumours then it would have been exploited by you know who on the what the name forum years ago.

ivanll

 

[Fishers Ghost]

The manual tells you bugger all about how to use the infinium correctly.
The machine is not more sensitive with the threshold turned up, it is simply that the weak tones are sharper and stand out more clearly; Well that is how it is for me and others who have tried it. Like most metal detectors, when you have become acustomed to a particular machine you become aware signal characteristics that even the manufacturer may not be aware of.

 

[bearkat4160]

Of course it is more sensitive with the threshold turned up...bugger yourself!

Try picking up a .5 gram gold nugget on threshold 1-2...then try 5-6..oh yeh...its more sensitive.

""it is simply that the weak tones are sharper and stand out more clearly;"" Hhahaha you just gave the definition of sensitivity.

Definition: Quick to detect or respond to slight changes.
Definition of sensitivity: Responsiveness

Alan

 

[Fishers Ghost]

With most metal detectors when you increase sensitivity you are actually increasing the level to which a signal will be amplified.(amplification Factor)

In the Infinium when you turn the Threshold down you are driving the threshold signal bellow zero + volts and it then becomes a negative going voltage and it takes the target signal along for the ride but the target signal does not decrease in strength as the threshold goes negative.

So for example, if your threshold is 1 volt + P to P and the target signal is 1 volt above the threshold then you will hear it, but if you wind the threshold 1 volt below zero that is - 1 volt P to P then the target signal for our given target will then still be 1 volt+ above the threshold but now it will be at the zero line and not be heard.

When you change the threshold level on the Infinium you do not change the amount that the target signal is amplified therefore the actual sensitivity to the targe remains the same no matter where you set the threshold.

If you display the threshold tone on a CRO (no target signal) and adjust the threshold up and down you will see the signal move up and down around the zero volt line and when you add a target signal it adds to the strength of the threshold and as I said earlier, if you then wind the threshold down you will see the entire waveform move down and the target signal will now be more difficult to hear, not because it is weaker but because you now only have a small part of the whole waveform poking above the zero line. The actual amplification factor remains the same. When you increase the threshold to almost max then the entire waveform plus target signal is now way above zero, and so it sounds louder.

Think of the threshold as the ocean and the target signal is the Titanic; When the waves are high you can see the titanic from far away when it rides high on the waves, but if it sinks below the waves ... well then it is still the Titanic and it is still there, it's just that now ya canny see it.

Once again I know what I am trying to say but it has turned out very confusing. Oh well I am getting very old now hey!!

 

[ivanll]

Hi
Is it true that a higher threshold setting on the Infinium LS increases depth? I am basing this question on some examples posted showing air tests, which appear to be affected by the threshold setting. If this is so, what is the maximum setting forum members recommend, before the threshold hum masks targets.

Dave

Perhaps visit your nearest local Authorised Garrett Dealer in Davonport and get a proper first hand demo, at least that service should be available.

ivanll

 

[Fishers Ghost]

Hi
Is it true that a higher threshold setting on the Infinium LS increases depth? I am basing this question on some examples posted showing air tests, which appear to be affected by the threshold setting. If this is so, what is the maximum setting forum members recommend, before the threshold hum masks targets.

Dave

Dave,
Just a short note that I forgot to mention in my previous post re the Infinium threshold.
The Infinium Threshold will never mask mask a target signal.
If you have a just audible target tone with the threshold set to just audible (with no target sig) then even if you turn the threshold up full blast you will still hear the target sig.

 

[cymro]

Hi
Is it true that a higher threshold setting on the Infinium LS increases depth? I am basing this question on some examples posted showing air tests, which appear to be affected by the threshold setting. If this is so, what is the maximum setting forum members recommend, before the threshold hum masks targets.

Dave

Dave,
Just a short note that I forgot to mention in my previous post re the Infinium threshold.
The Infinium Threshold will never mask mask a target signal.
If you have a just audible target tone with the threshold set to just audible (with no target sig) then even if you turn the threshold up full blast you will still hear the target sig.

This clears things up for me thanks again to all who have responded to my question.

Dave