TDI discrimination

[Orbit]

With little change in the scheme gs 4 is extremely stable device and in no autotune mod original GS 4.buried object at 120cm in ground ,subject 20x30cm GS4 reveals quite surely more 20 to 30cm in the air coil 27cm al off taken off bottom protection ,for problems with static !signal occurs to me when I crossed hand near coil ??? so i bought it a little strangely but true I took off my more no problem with static and ceramics !? why is bottom protection rules the problem ?????

[Geo]

With little change in the scheme gs 4 is extremely stable device and in no autotune mod original GS 4.buried object at 120cm in ground ,subject 20x30cm GS4 reveals quite surely more 20 to 30cm in the air coil 27cm al off taken off bottom protection ,for problems with static !signal occurs to me when I crossed hand near coil ??? so i bought it a little strangely but true I took off my more no problem with static and ceramics !? why is bottom protection rules the problem ?????

Sorry i don't understand you

[mikebg]

Sorry i don't understand you

Me too.
We need Orbitenglish to English translator.

[Reg]

Hi Geo,

I am not sure of your question(s) but I will try. First. There will be a loss in depth when using the GB simply because there is a subtraction action occurring. So, when you turn on the GB, the GB channel is subtracting a portion of the signal from the main signal. Thus, there is going to be the loss you see and in some cases more of a loss with the GB on. That is the down side of using the GB on mode.

Now, as far as your ability to detect an object deeper in the ground than in the air, that can be partly because the air test usually has more EMI noise to contend with, so the weak signal gets lost in the noise. This is especially true if you have the coil pointed into the air and not parallel to the ground.

As for being able to lift the coil more off the ground so it would appear you might be able to detect an object deeper, well, sometimes there is the perception this will occur, but when you actually bury an object deeper to the point you have the object at what you think would be the maximum depth of detection, you may not be able to detect it. I have noticed this strange condition also, and it is why at times I am not that worried about raising the coil a little.

Also, I have found that some ground conditions do help with the detection of buried objects. Concentrations of black sand at just the right location seem to be able to enhance the depth. I suspect this occurs because the transmit signal has a tendency to concentrate in ferrous objects even in black sand. So, at certain times strange things can occur that really are not abnormal, but the reasons are not known.

Last but not least, the detector detects the sum of all the targets under the coil, so even a small object that isn't detected by itself just may help in the detection of another.

I am not sure if I answered your question.

Reg

[maikl]

Sorry i don't understand you

I'll try to help:
with GS4 (without autotune), detects object 20x30cm in the soil, a depth of 120 cm, a coil of 27 cm. It also detected in the air at a distance of 90-100cm.
He had a problem with the shield of the coil (detect hand and ceramics). Problem is solved by rejecting the second (outer) shield of the coil.
He asks why the second (outer) shield made problems?


@Geo, have you tried the detection of small gold with TDI (for example, small gold earrings)? What is the detection was in the air (for example, 30 cm coil)?

[Geo]

Hi Geo,

I am not sure of your question(s) but I will try. First. There will be a loss in depth when using the GB simply because there is a subtraction action occurring. So, when you turn on the GB, the GB channel is subtracting a portion of the signal from the main signal. Thus, there is going to be the loss you see and in some cases more of a loss with the GB on. That is the down side of using the GB on mode.

Now, as far as your ability to detect an object deeper in the ground than in the air, that can be partly because the air test usually has more EMI noise to contend with, so the weak signal gets lost in the noise. This is especially true if you have the coil pointed into the air and not parallel to the ground.

As for being able to lift the coil more off the ground so it would appear you might be able to detect an object deeper, well, sometimes there is the perception this will occur, but when you actually bury an object deeper to the point you have the object at what you think would be the maximum depth of detection, you may not be able to detect it. I have noticed this strange condition also, and it is why at times I am not that worried about raising the coil a little.

Also, I have found that some ground conditions do help with the detection of buried objects. Concentrations of black sand at just the right location seem to be able to enhance the depth. I suspect this occurs because the transmit signal has a tendency to concentrate in ferrous objects even in black sand. So, at certain times strange things can occur that really are not abnormal, but the reasons are not known.

Last but not least, the detector detects the sum of all the targets under the coil, so even a small object that isn't detected by itself just may help in the detection of another.

I am not sure if I answered your question.

Reg

Hi Reg.
Thanks for info. Your messages are seminars .

Regards

[Geo]

I'll try to help:
with GS4 (without autotune), detects object 20x30cm in the soil, a depth of 120 cm, a coil of 27 cm. It also detected in the air at a distance of 90-100cm.
He had a problem with the shield of the coil (detect hand and ceramics). Problem is solved by rejecting the second (outer) shield of the coil.
He asks why the second (outer) shield made problems?


@Geo, have you tried the detection of small gold with TDI (for example, small gold earrings)? What is the detection was in the air (for example, 30 cm coil)?

I never tried to detect small golden objects as the earings. But very often i detect at fields, lead shots by bird hunter, very easy with the 30cm disk above the ground 20cm

[maikl]

I never tried to detect small golden objects as the earings. But very often i detect at fields, lead shots by bird hunter, very easy with the 30cm disk above the ground 20cm

Lead, copper...no problem, the problem is with the gold of the same size...
I noticed that you do not care nugget shot and little gold (earrings, necklaces...), but the TDI is designed to do just that, GB control is therefore set, classic PI detector can not operate below 15us (on the ground) because it does not have GB control.
My opinion is that you do not need to use GB control (and losing the detection), because what you're asking is above 20us...
Best regards.

[Geo]

Lead, copper...no problem, the problem is with the gold of the same size...
I noticed that you do not care nugget shot and little gold (earrings, necklaces...), but the TDI is designed to do just that, GB control is therefore set, classic PI detector can not operate below 15us (on the ground) because it does not have GB control.
My opinion is that you do not need to use GB control (and losing the detection), because what you're asking is above 20us...
Best regards.

With the GB=off, there is problem with moisture and old ceramics.
With few words..... not so easy pazl

Regards

[maikl]

With the GB=off, there is problem with moisture and old ceramics.
With few words..... not so easy pazl

Regards

It would be easy if it could the delay rise above 25us... unfortunately, the TDI is not possible...
Best regards.

[Geo]

With delay=25 TDI begins to lose the ability to reject the old ceramics.
With more delay.... more problems

Regards

[Orbit]

I think the problem is that it tdi uses an identical width in channels ! Do we only have two unknown channel or three channels ,in my third channel should have a greater breadth of sampling for example 75ms I like this managed to create a channel for for tons of iron But if you do not set the correct width sampling and the passage of signals through gate If the sampling is set to below 25ms has a problem with ceramics ! in this channel for iron should be adjusted so that the ceramic magnet be invisible ,Only then will a combination of the other two channels that, like I told I think the same width delay one can Command delay set to less than 25ms and that there is no problem with ceramics !

[maikl]

When the delay under 25us, there is a problem with wet soil, when PI detector used in the field, forest ...
Problem with ceramics ("Roman bricks") and wet soil, there in the first 15cm...
The Deepers Detectors (8AT, 10DD, X5...) that was solved the holding coil at a height of 10cm-15cm from the ground...
Here's an excerpt from it manual Deepers X5 (that does not have ground balance):

[Orbit]

Regards Majkl ! What I wrote above I thought when the device is operating in Mode geb !for example I'm working on the device has several modes and the mode in which the geb off ,and when the two modes geb operational ,the first of the two modes excludes the impact of the country and ejects iron objects In this mode I have a special tone for iron but how to move your command geb So is ejected and iron object has no particular tone of the exhibit Only a VCO that works similarly tdi as he does when he is off geb ,while in the third mode threshold tons of 400hz which is a constant If you are below the coil finds iron object VCO so that by withdrawing the lower tone=while if it below coil find precious metal or no iron VCO sound rises up up if the target nearest to the coil VCO frequency sound goes up to 1khz !

[Orbit]

Hi.
Some years ago i posted the below table.
As i see now, TDI detected one gold coin as high conductivity with delay=10 and GB between 7 and 11. But for 45 coins it reversed the conductivity!!!!!.
For delay=10 and GB= 7...9 TDI has the lower depth for gold. So I must make again the test with the 45 coins and i think that it is time to change the adjusting of the TDI and the way that i use it. Maybe it is time to keep low or high GB and the coil far from the ground ......

Do this test relevant to all whites tdi detector in working condition ?