Deep-weak signal adjustment?

[sgoss66]

Bryan -- so it IS called "VOLUME gain," on the E-Trac. I'm thinking that it's just called "gain" on an Explorer, but can't recall for sure. At least VOLUME gain is better than "gain," but you are right...with no industry standard for the terms, it can be confusing.

Steve

 

[IDXMonster]

On the Explorer there’s a menu that has “Volume” and two other things,then when you press the button next to “Volume” it takes you to the screen with Gain and Max Limits....so Gain is within the choices of Volume adjustments.

 

[sgoss66]

Yeah, that's right, IDX. NOW I remember. It IS just called "Gain," but it is under the "Volume" menu category, implying "volume gain."

Thanks for jogging the old memory!

Steve

 

[sgoss66]

Oh -- one more small detail...forgive me above, but I was talking about "cranking your volume gain to 10," implying that "10" is maxed out. ON the Explorer, 10 IS maxed out, but I think the E-Trac may adjust from 1-30 or something on the volume gain setting. Just wanted to clarify there. I was thinking "Explorer" but saying "E-Trac" in terms of the gain numbers! DUH!

Steve

 

[dewcon4414]

This will be interesting to see.....more of a how will people tweak the machine to coax weak signals. Sometimes its merely get the best out of the machine....... if you dont set any machine up right you will miss those weak signals. Iron bias.... GBing....tone freqs....and threshold levels are just a few you need play with. Cant say enough about HEADPHONES either guys.... you need good ones with good response and the ability to keep noise out.

 

[IDXMonster]

Just like anything else,I’ll have to see all this magic for myself.

 

[jyblood]

All I know is that for us older with hearing that's not as good as when younger, the adjustment brings those weak audio signals up to where I can hear them. Also, the NOX don't have auto sensitivity, maybe the next flagship unit will have these upgrades and more. Thanks guys

 

[Jason in Enid]

Jason --

The more I think about this, the more I think we ARE talking about the same thing, but describing it in different ways; two different ways of visualizing the same thing. Consider my crude picture, below...



In that figure, let's define the blue line labeled "detection floor" as the weakest signal the machine can detect, and the other blue line labeled "sensitivity threshold" as the level of signal allowed to be passed on through on to the user. And let's define the gray jagged line as representing signals received by the detector.

By me saying sensitivity is "amplifying the receive signal," that suggests that "sensitivity threshold" line is fixed, and increasing sensitivity shoves the gray jagged lines upwards, such that more of the signal peaks (gray line peaks) end up being above the "sensitivity threshold" and thus can be heard by the user. YOU are saying that the gray jagged lines remain fixed in place, but that it's the sensitivity threshold line that is adjustable, such that increasing sensitivity shoves that blue line downward, and thus more of the signal peaks (gray line peaks) end up above the "sensitivity threshold," and thus can be heard by the user.

Either way, it ends up being the same thing, right?

Thoughts?

Steve

LOL, yep, same concept, different explanations.

 

[vlad]

with the front end and allows you to add more signal transmitted (as opposed to sensitivity which is the receiver); at least
this is the way George Payne, Troy Galloway and Mr.Bill explained it to me.
A standard in the industry would clear up the confusion; but we have countries around the world making detectors, so...
On demodulated (saturated) audio Monte posted this before:
When I use it, like any detector I own, I like to get the most performance possible when I am hunting any site where older and/or deeper targets might be. A saturated audio design requires a certain amount of target signal response in order to be 'accepted' and then process to response with the full-strength saturated audio. If the targets is too small or too deep, the signal might not be process and, therefore, I can't get the best depth like I would out of something similar (like an Omega using the d1 or d2 Audio Tone ID option).

 

[sgoss66]

with the front end and allows you to add more signal transmitted (as opposed to sensitivity which is the receiver); at least
this is the way George Payne, Troy Galloway and Mr.Bill explained it to me.

Makes total sense, but it would appear that George Payne forgot to tell his engineers that with the Equinox, with the manual calling sensitivity "receive gain!"

Steve

 

[TomNH]

Gain is the measure of amplification. Turning down gain will cause audio to reduce & noise to increase but not always go away at some point.
Turning it up causes more volume but too much causes distortion like clipping.
Squelch is a circuit that cuts off low level signals completely at a usually adjustable point.
Clipping is almost the same as squelch but caused by accident usually.
Modulation is adding "information" to a pure signal.

Anyhows my Safari has a sensitivity control. Reducing it causes falsing to go down more & more BUT with no reduction of volume.
In other words it GO/NOGO, a squelch circuit.

Transmit power. If you raise it the signal will go deeper but give more falsing. Shallow objects will overload ( OVERLOAD on Safari ).
Low power will be very quiet but only go shallow. Want to miss a peace $ at 5" due to low TX power ?
Noise. Noise is generated buy the electronics. Best examples are the hiss on a blank FM channel or the snow on a TV. Most if it
is internal. In fact it is a sign that things are probably working right ! Some noise also comes from man made ( QRM ) sources
like power lines. Other from nature ( QRN ) such as lightning.

Hope that was some use to somebody. Time for a brew.

Tom N.H.
LFOD !

 

[IDXMonster]

Interesting Tom. Only a very few machines have actual TX power adjustment so in the vast majority of cases,anything that we as operators are controlling has to do with the return signals,as you know. Minelabs way of processing information has some real tricks going on for them to be SO successful for SO many people for SO long.

 

[TomNH]

Interesting Tom. Only a very few machines have actual TX power adjustment so in the vast majority of cases,anything that we as operators are controlling has to do with the return signals,as you know. Minelabs way of processing information has some real tricks going on for them to be SO successful for SO many people for SO long.

Only reasons I can think of to cut TX pwr is a quick & cheap way to work bad ground & some more battery life. My also be handy
for inexperienced. Like a cop looking for on the top shells etc.
I agree ML software & engineering is as good if not better than any. Just go to the patent dept site & see all the patents !

C U later
Tom
LFOD !

 

[Jackpine Savage]

On the X-Terra 705 I found I could boost the audio a couple inches closer to max depth by setting the volume on my headphones all the way up and use the detector to set the overall level.

A tip to save your hearing:

When adjusting the volume start out at a LOW setting and increase to a comfortable level on large shallow targets. Don't start at a high level and decrease it. The way our ears work doing it that way will always leave you at a higher setting and more volume than necessary.

Tom

 

[IDXMonster]

On the X-Terra 705 I found I could boost the audio a couple inches closer to max depth by setting the volume on my headphones all the way up and use the detector to set the overall level.

A tip to save your hearing:

When adjusting the volume start out at a LOW setting and increase to a comfortable level on large shallow targets. Don't start at a high level and decrease it. The way our ears work doing it that way will always leave you at a higher setting and more volume than necessary.

Tom

How our ears work...I have played drums for many years,don’t anymore for lack of interest. A buddy of mine who plays guitar and I would jam in his basement for a few hours years ago. When I went to go home,for the first 10 minutes of the ride I could not hear my car running,and it was not a quiet car. Point is...this IS how our ears work. When we sense input is too high,they start to “close up”. We have some ingenious DNA!

 

[Tony N (Michigan)]

On the X-Terra 705 I found I could boost the audio a couple inches closer to max depth by setting the volume on my headphones all the way up and use the detector to set the overall level.

A tip to save your hearing:

When adjusting the volume start out at a LOW setting and increase to a comfortable level on large shallow targets. Don't start at a high level and decrease it. The way our ears work doing it that way will always leave you at a higher setting and more volume than necessary.

Tom

Hi Tom,
My headphones do not allow loud sounds to come through. It has a built in limiter.
However, the new wireless headphones that come with the Nox may not have such a limiter.