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Auto Sensitivity, how good is my dirt?
Posted by: Dailydigger
Date: May 07, 2017 10:05PM
I have noticed that the auto sensitivity will change depending on my dirt sometimes it will be at 14 and sometimes it will hit 22. I just hunt parks here in Arizona and the ground is pretty hot around here. The CTX is more stable than the Explorer Se.

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Re: Auto Sensitivity, how good is my dirt?
Posted by: flysar
Date: May 07, 2017 10:12PM
Its a lot better than mine. In A+3 I get 8-12 and I'm really happy when I see 18 (lots of top soil).
HH

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Re: Auto Sensitivity, how good is my dirt?
Posted by: mrwilburino
Date: May 08, 2017 08:04AM
I've got some spots where I've hit 30 in auto +3.



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Re: Auto Sensitivity, how good is my dirt?
Posted by: Champ Ferguson
Date: May 08, 2017 10:38AM
Using Sensitivity to judge your dirt is one of the best features of the CTX. When Auto gets down too low, you need to start forcing the limits of stability in Manual.



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Re: Auto Sensitivity, how good is my dirt?
Posted by: Dailydigger
Date: May 08, 2017 11:35PM
Thanks for the info.

Re: Auto Sensitivity, how good is my dirt?
Posted by: Dailydigger
Date: May 08, 2017 11:38PM
Interesting to see what other people are getting in there area.

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Re: Auto Sensitivity, how good is my dirt?
Posted by: Champ Ferguson
Date: May 09, 2017 09:03AM
In Auto+3, my CTX runs from almost max sens to as low as 7(rare). Mostly hi teens but much better in rich loamy stuff.
In Manual, I can always force a bit higher.

Remember every site is different and you need to match the settings to the soil.



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It's not the dirt, it's EMI that regulates sensitivity...
Posted by: Chris(SoCenWI)
Date: May 09, 2017 09:41PM
It is electrical noise that determines sensitivity level. Out in the country or in big parks sensitivity tends to run pretty high. In town, especially near power lines sensitivity runs low. Same dirt.

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Re: It's not the dirt, it's EMI that regulates sensitivity...
Posted by: Champ Ferguson
Date: May 09, 2017 09:52PM
Certainly it affects it Chris, but soil can change drasticallyin content and that is also a factor. There isn't always spurious electrical.
Not to mention what man has done to the soil. Ever hunt near an old iron furnace?



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Re: Auto Sensitivity, how good is my dirt?
Posted by: mrwilburino
Date: May 11, 2017 12:55AM
I'm not so sure about emi affecting the sensitivity level. I've tested this out a couple of times by carrying the machine (with coil in the air) from an area of fairly low emi to an area of high emi (and vice-versa), with no change at all in the recommended sensitivity number or the actual sensitivity level (was using auto) until the coil was back on the ground and swinging. I think it's strictly tied in with the ground tracking system and based on mineralization levels.



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Re: Auto Sensitivity, how good is my dirt?
Posted by: jas415
Date: May 11, 2017 06:57AM
In the Houston area I run it in manual at about 26-27 ALL the time. The only time I ever see the 'auto' numbers or pay any attention to them is when I am on some sort of Iron ore driveway. Many years ago some folks made their driveways or roads out of a red crushed looking dirt, and that is tough to hunt in.

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Re: Auto Sensitivity, how good is my dirt?
Posted by: amberjack
Date: May 11, 2017 09:01AM
discount the jibber jabbers @ your own risk :buds:

AJ

I would call that trash, not dirt...
Posted by: Chris(SoCenWI)
Date: May 20, 2017 09:14PM
Champ,

We debated this until the cows came home in the old days. The original explorers did not show what the sensitivity level was in auto. Many or most of felt the the machine would dial the sensitivity way lower than needed in high trash ground. Basically it sees all the trash signals, thinks it is EMI and cuts sensitivity. The CTX shows you what it thinks it should be running at. I can detect up at our lake place, around the cabin there is EMI and trash. A few feet away ground that has never been developed. Same dirt, much different recommended levels.

Chris

That hasn't been my experience....
Posted by: Chris(SoCenWI)
Date: May 20, 2017 09:22PM
MrWilburino,

I've turned my Explorer XS detector on in the house around electronics and wires and generally could not run sensitivity higher than single digits or it would go nuts. This is with the coil up in the air. Don't remember if I've done it with my CTX. I do know I've used it many times outside, under power lines, near electric dog fences, much lower sensitivity. Get away from the EMI, then I'm able to crank the sensitivity up. Same dirt. If we are considering high trash, especially ferrous content to be "dirt" different story. As I posted below an abundance of targets can cause the machine to dial down the sensitivity.

Chris

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Re: Auto Sensitivity, how good is my dirt?
Posted by: mrwilburino
Date: May 21, 2017 07:54AM
Chris, I'm not saying that the CTX isn't affected by EMI; it definitely IS, just like any other machine, which is why we sometimes have to turn the sensitivity down to deal with it. What I am saying, based on observation, is that when the CTX is being run in auto sensitivity, it does not automatically adjust the sensitivity level to compensate for EMI like it does for ground mineralization. Nor does it show any changes in the recommended sensitivity number (the green number) based on EMI levels. Changes in auto sensitivity and the recommended sensitivity number appear to be based entirely on feedback from the ground tracking system. The only time the CTX appears to monitor (and adjust through channel selection) for EMI is during the noise cancel process.



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