FTAO...any minelab technicians who can help

[Rex123]

This post is going to be in 2 parts, but first I need a question answering.

What is the 3030 SEEING to generate a SUGGESTED sensitivity level

my reason for asking to follow any replies, thank you.

 

[amberjack]

short answer to that question is not in this lifetime and probably not the next either

but I would say ground 1st then emi (jibber jabber) and yes that is the technical term for emi and associated noise... what else is there ??

AJ

 

[JJ]

That is a great question. In fact, I would make a wager that you could put a line of CTX's with the same settings over the same soil and get various suggested sensitivity readings. I only say this because I toggle between auto and manual and usually get a new higher set of numbers when back in auto. There seems to be no rhyme or reason why the numbers change or go up. Just my observations, JJ

 

[Digger]

What is the 3030 SEEING to generate a SUGGESTED sensitivity level

The "Suggested" level is the average Sensitivity Level of the high, medium and low channels.


Here is part of a post that I made on this forum, regarding Auto Sensitivity:
The CTX 3030 has three internal signal channels (high, medium and low) used to identify targets. The CTX 3030 continually measures the magnetic ground interferences that affect these channels and adjusts the level of Sensitivity individually for each channel, to provide the most stable TID for each channel. When using Auto Sensitivity, the left bar and numeric value indicates the highest Sensitivity Level that either the high, medium or low channel is operating on. The right bar indicates the "Suggested" Sensitivity Level, as determined by the CTX 3030. This "Suggested" level is the average Sensitivity Level of the high, medium and low channels. Each channel is set to a different level of Sensitivity individually by the CTX 3030 to provide the most stable TID's. As an example....... if the CTX 3030 determines the Sensitivity Level for each channel is to be High = 20, Medium = 17 and Low = 11, the left hand bar and numeric indicator will read 20, representing the highest Sensitivity level of the three channels. The right bar and numeric indicator will display the average of the three channels, which is 16. 20 + 17 + 11 = 48, divided by 3 = 16. When you implement the Auto Sensitivity offset with an offset of +3, it will not suddenly change the value of both bars by 3. Instead, it increases each channel's value by 3. So in the example given earlier, the channels will become High = 23, Medium =20 and Low = 14. 23 + 20 + 14 = 57, divided by 3 = 19. So the left bar and numeric indicator will display 23, representing the highest Sensitivity level of the three channels. When using an "offset" the numeric value of that offset will also be displayed in a little icon, to the left of the left Sensitivity bar.

In a nut shell, there are two types of ground mineralization......magnetic mineralization and conductive mineralization. An extreme example of magnetically mineralized ground would be "red dirt" or soil that is comprised of iron particles. An extreme example of conductive mineralization would be a salt water beach (without black sand). Magnetic mineralization can cause the ground to become magnetic. Salt mineralization causes the ground to become conductive. Either type of mineralization can produce false signals and/or mask targets. As you sweep the coil, Automatic Sensitivity and Ground Compensation monitor the full band of frequencies for changes in ground mineralization. Auto Sensitivity automatically adjusts the CTX to maintain maximum depth. And the Ground Compensation circuitry removes false signals caused by fast changing levels of ground mineralization to maintain maximum detection depth and sensitivity. The CTX is designed to provide very accurate analysis of magnetic mineralization. But Auto Sensitivity doesn't perform as well in conductive mineralization areas, which is why they don't recommend using Auto Sensitivity in Salt water hunts. (conductive mineralization). Here is the link to a Treasure Talk blog written by Nenad Lonic, a Minelab engineer, regarding how Auto Sensitivity responds in various conditions. http://www.minelab.com/usa/go-minelabbing/treasure-talk/ctx-3030-auto-vs-manual-sensitivity

Hope this helps. HH Randy

 

[bklein]

What is your source for the discussion about "3 signal channels"? Thanks.

 

[Digger]

The three channel information was provided to me during the development process. HH Randy

 

[mrwilburino]

Good information, thanks Digger.

 

[bklein]

I ask because I looked at the reference patents and they go into what's happening in some detail. They discuss both frequency and time domain approaches and mention "two or more channels".
I am seeing that the machine comes up 16/14 and takes a few minutes to stabilize in Auto. It may be doing either a NC or GB first as ID's are stable. If I come up in Manual the ID's aren't stable until I do a NC (or raise it up to 9 or higher).
See what I found in the Calibrate Coil thread.

 

[Digger]

I ask because I looked at the reference patents and they go into what's happening in some detail. They discuss both frequency and time domain approaches and mention "two or more channels".
I am seeing that the machine comes up 16/14 and takes a few minutes to stabilize in Auto. It may be doing either a NC or GB first as ID's are stable. If I come up in Manual the ID's aren't stable until I do a NC (or raise it up to 9 or higher).

The first thing I do after I turn on my CTX 3030 is sweep the coil over the ground to make sure there aren't any targets under the coil. The next thing I do is hold the coil parallel to the ground (about a foot high) then I run an Auto NC. I don't even look at the "other numbers" or adjust any other settings until after I've done an Auto NC. I also run an Auto NC periodically during the hunt, just to make sure I'm maximizing the CTX 3030 performance. Sometimes I will "bump" the NC manually, just to see if I can find a channel that is quieter, instead of lowering the Auto Sensitivity offset. If I am using Manual Sensitivity, I always run another Auto NC whenever I adjust the Sensitivity.

NC will not change channels "on the fly". It remains on the channel you have set, until you change it. The GB operates on a different channel than those used by Sensitivity. So in regard to your question regarding stabilization, in my opinion, neither the channels used for NC or GB have an adverse effect on the stability of Auto Sensitivity. With that said, changing ground conditions affect both the automatic ground compensation circuitry and the suggested sensitivity levels. If you do NOT enable GB and run in Auto Sensitivity, both are automatically adjusted for by the CTX 3030. JMO HH Randy