TESORO GOLDEN SABRE

[Max]

Oooh!Huh! I had same doubts about Payne's and Giffords explanations! Sssheeeesh! I tought all missunderstandings came due fact that i am Serbian and English is not my primary language, so i couldnt understand some phrases or slang they might be used.....It was pretty strange from the start!? In 2004. i downloaded almost all intersting patents from uspto.gov.net...At the time it was possible to install Alternatiff plugin and see originals, also download them. Now i think they changed something. I cant see and download any more from there?
The heck...!
Max, today i experimented a bit more with nulling. I made another coil, but this time larger one,eliptical (copy of Garrett Eliptical shape)..So i did like you suggested-put 1K on RX and of course 15nF. All measurements done with multimeter at 200mV AC. Well....i was right; when almost nulled, but without resistor, voltage is 0.012mV. With resistor was 0.009mV...? Fake as i told you! It is much easier to look at 0.012mV and null a bit more coil to achieve less voltage than to look at 0.009mV...if you know what i mean. Less error!
So when i gain 0.000mV only with 15nF and later add 1K, voltage remains 0.000mV - no changes of course. But if i try to achieve 0.000 with resistor included...and gain it, and later discinnect it an measure again; i gain some voltage not absoulute zero, for example 0.002mV...So resistor produced error of 0.002mV....I think that's why your coil is giving you some 5.5mV. You probably used oscilloscope to measure and resistor was included there..
I insist you (for your benefit) to try with some opened coil and see yorself.
Just put 15nF without resistor. Null it as less as you can. Than add rsistor and you'll read higher voltage for sure...on oscilloscope or multimeter, the same....

Hi Ivconic,
thanks for the hint, I'll do that way next time... I'll use also one multimeter + the scope to compare readings from both.

Thanks again,
Max

[Max]

Hi Max
Τhank you for your information. I deal with photosensitive pcbs more from 20 years without particular problems. But now I cannot occupy what happens ...... likely the photosensitive material it spoiled. I bought from ebay 2 sprey in order to convert normal pcbs in photosensitive other again it does not work. I expose pcbs in UV for 8 seconds and afterwards i immediately present in caustic soda. it is presented the drawing and automatically is dissolved the photosensitive material and remains only the pcb. Really this time I have all lost. We will see......
My Regards

Hi Geo,
8 seconds ? What's the power/number of your UV lamps ?

Maybe you mean 8minutes ?

If you expose for 8seconds and stuff goes away in soda solution that means the photoresist is totally busted.

I have a 32Wx4 UV set and it took from 3 to 5 minutes do shoot circuit on photoresist... depending on type of it, how much is old etc.

Normally I use 4minutes timing (the unit has a 0-10minutes programmable timer) and get extremely good results with factory made photoPCBs... and also my own sprayed ones.

Timing for old photoresist I used are from 2 minutes to 8 minutes... but it's rare I use old stuff... I've done in the past and waste lot of time with that.

I use fully transparent sheets with laser or ink-jet drawings (black)... ink-jet when pads and tracks are large...laser for thin stuff (e.g. like computer cards).

Soda-solution need to be 10gr in 1Liter or less (7-8gr/Lt are good for 30seconds developing)... 10gr require often 15-20 seconds to make melt/dissolve all the residual stuff.

I use also 1gr/Lt for desperate cases... when I need more time...and "care".

When you buy the spray there must be a label on can or a separate instruction sheet with developing procedure and hints... there must be also suggested exposition time.

Best regards,
Max

PS: I hope you solve that problem quikly so you'll have your TGS/TGSL up and running... it's worth !

[ivconic]

"...Just put 15nF without resistor. Null it as less as you can. Than add rsistor and you'll read higher voltage for sure...on oscilloscope or multimeter, the same...."

"read same voltage for sure.." - error!

Or do oposite; null it with resistor included,than omit resistor and you'll read HIGHER voltage for sure! So less error in readins (and nulling) will be if resistor is omitted!
I confuse myself with all those explanations here...!?
How the heck you will understand this...!?
Regards!

[ivconic]

TGSL "Katana"...

[ivconic]

Those are 2 coils i made yesterday and today.Drying yet. It will need few more
hours to get dried and stiff.Also there is a mass which used to fill up coil
housings. Sort of 2 component pitch. When dried, it is hard and fast as steel.
Best so far. Cold drying no relative movements. Larger coil is 800gr and smaller
680gr. A bit heavy but almost unbreakable. I can hit it with hammer very
hard - not even a small scar...Superb!
And photo of my (my personal-not for sale) TGSL, which i am using now.
The one who collected those 254 coins in no time. Real killer! Coinkiller!
I didnt payed much of attention on appearance, it is a bit brute but real
machine!
Others i made for sale are looking much better,nice outfit...Havent neither one
right not to take photo. I'll do that next time when finished...

[ivconic]

Oooh!Huh! I had same doubts about Payne's and Giffords explanations! Sssheeeesh! I tought all missunderstandings came due fact that i am Serbian and English is not my primary language, so i couldnt understand some phrases or slang they might be used.....It was pretty strange from the start!? In 2004. i downloaded almost all intersting patents from uspto.gov.net...At the time it was possible to install Alternatiff plugin and see originals, also download them. Now i think they changed something. I cant see and download any more from there?
The heck...!
Max, today i experimented a bit more with nulling. I made another coil, but this time larger one,eliptical (copy of Garrett Eliptical shape)..So i did like you suggested-put 1K on RX and of course 15nF. All measurements done with multimeter at 200mV AC. Well....i was right; when almost nulled, but without resistor, voltage is 0.012mV. With resistor was 0.009mV...? Fake as i told you! It is much easier to look at 0.012mV and null a bit more coil to achieve less voltage than to look at 0.009mV...if you know what i mean. Less error!
So when i gain 0.000mV only with 15nF and later add 1K, voltage remains 0.000mV - no changes of course. But if i try to achieve 0.000 with resistor included...and gain it, and later discinnect it an measure again; i gain some voltage not absoulute zero, for example 0.002mV...So resistor produced error of 0.002mV....I think that's why your coil is giving you some 5.5mV. You probably used oscilloscope to measure and resistor was included there..
I insist you (for your benefit) to try with some opened coil and see yorself.
Just put 15nF without resistor. Null it as less as you can. Than add rsistor and you'll read higher voltage for sure...on oscilloscope or multimeter, the same....

[Geo]

Hi Geo,
you can try reducing time of exposition... and making the solution more weak... to give you more time when removing eccess resist from it... but it could work or not depending of status of photoresist... sometimes the alteration is on 100% of it so you simply cannot reach your result with it.

Heat is the big problem for conservation of that boards... then time is the second critical factor (1-3 years good, 3-7years still good, more than 7years... is a challenge!)

The big problem with lowering the time is that some resist could remain there ! and is very tricky finding the right "seconds" of UV (yes seconds) you need to remove it good from board.

One time I repeated 22times the procedure to get a working PCB from old stuff...more than 10years old. After that I've made it good... but then considering the time and efforts required... it isn't any good and so I recovered boards and painted with new photoresist can all them. And now I make smaller PCBs at first attempt with them!

If you have many boards of good quality... I suggest you clean them one by one and buy a can to repaint again with fresh resist (I've done 35 small 10cmx8cm using a 12eur can), then find a cool place to store using a black paper or similar to cover from light.

Best regards,
Max

Hi Max
Τhank you for your information. I deal with photosensitive pcbs more from 20 years without particular problems. But now I cannot occupy what happens ...... likely the photosensitive material it spoiled. I bought from ebay 2 sprey in order to convert normal pcbs in photosensitive other again it does not work. I expose pcbs in UV for 8 seconds and afterwards i immediately present in caustic soda. it is presented the drawing and automatically is dissolved the photosensitive material and remains only the pcb. Really this time I have all lost. We will see......
My Regards

[Qiaozhi]

Hi,
I'm drinking the coffee... and I remembered all the story about confusion and references

In the Gifford's (well is my reading of it) system the reference is on the Y axe and positive are clockwise measured:
at -90 (-X axe) he has ferrite response... and clockwise turning a +5° he has the "limit" for soil if we talk about Payne's stuff so: -90+5 = -85°

Actually he has mixed up stuff too on figure nr. 2 of patent giving an "alternative" way (compare fig.1 and fig.2 ... in fig.2 the +R axe that lay at +90 is actually the origin for fig.1 , with phase equals zero)!

Payne's coordinate system uses also an axe as reference for angles BUT counterclockwise for positive angles ...so Payne's -5° describe a movement like +5° for Gifford (here the confusion):

when he said that ferrite is zero he means that he's in the origin, on the reference axe, with the ferrite response... and when he said that a soil could give till -5° he means that conductive (R component) make RX signal shift phase clockwise respect to ferrite response (pure mineral)... like happens when a conductive metal effect is detected.

The confusion is in that Payne's method uses negative angles for effects due to increasing conductance ... where Gifford's uses the positive for that.

That's why I think Gifford's method is better... cause when can talk of negative phase for e.g. iron... and positive for silver... and not the opposite.

Of course, just conventions... but all this stuff is really confusing changing the reference all the times.

Kind regards,
Max

I agree - this is all very confusing. However, I think Fig. 2 is correct in Gifford's patent. The axis values are referring to the phase of the oscillator, whereas the target phases refer to the received signal. For example, at the top of Fig. 2 it says 0 degrees "X" axis, and "mineral in soil". The 0 degrees is shown in the top waveform of Fig. 1 for the oscillator and is marked as "Mineral Sample Phase "X". "Mineral in soil" in Fig. 2 refers to the phase of the second waveform of Fig. 1 measured at the 0 degree point of the oscillator. All the other target information follows on from this.

[Max]

Damn! I wrote AXE for AXIS...

Maybe is cause of the coffee...

I need a vacation !

[Max]

Yes - there's a lot of confusion here, and I think it's done on purpose.
It appears to me that it really depends on where you place your reference point. Also, there is an assumption that these values represent the actual phase-shift produced by the various targets. In reality they seem to be the value of the phase-shift required to reject the particular target, and will once again depend where you set your reference point.

For example, first set up your detector to reject iron. i.e. with the sample pulse for the DISC channel located at the peak of the RX signal. Note this position. Then rotate the DISC control until you can just reject a pulltab. Measure the phase shift between the two positions. I expect you will find it is somewhere between 80 and 110 degrees, depending on the type of pulltab. This matches Gifford's patent.

Also, in the patent, minerals are shown at -90. This refers to the mineral sample point (phase "X") and does not literally mean "minerals". To discriminate against mineralized soil (i.e. contains some iron) we would need to add up to 5 degrees, and -90 +5 = -85 degrees. But again, this is somewhat confusing, because we really need to adjust the GEB channel to ignore mineralized soil, not the DISC channel. In this case, we need to subtract 5 degrees.

You just need to make yourself a coffee, and draw a few diagrams to get your head around this. And (of course) do some scope measurements on the circuit.

Hi,
I'm drinking the coffee... and I remembered all the story about confusion and references

In the Gifford's (well is my reading of it) system the reference is on the Y axe and positive are clockwise measured:
at -90 (-X axe) he has ferrite response... and clockwise turning a +5° he has the "limit" for soil if we talk about Payne's stuff so: -90+5 = -85°

Actually he has mixed up stuff too on figure nr. 2 of patent giving an "alternative" way (compare fig.1 and fig.2 ... in fig.2 the +R axe that lay at +90 is actually the origin for fig.1 , with phase equals zero)!

Payne's coordinate system uses also an axe as reference for angles BUT counterclockwise for positive angles ...so Payne's -5° describe a movement like +5° for Gifford (here the confusion):

when he said that ferrite is zero he means that he's in the origin, on the reference axe, with the ferrite response... and when he said that a soil could give till -5° he means that conductive (R component) make RX signal shift phase clockwise respect to ferrite response (pure mineral)... like happens when a conductive metal effect is detected.

The confusion is in that Payne's method uses negative angles for effects due to increasing conductance ... where Gifford's uses the positive for that.

That's why I think Gifford's method is better... cause when can talk of negative phase for e.g. iron... and positive for silver... and not the opposite.

Of course, just conventions... but all this stuff is really confusing changing the reference all the times.

Kind regards,
Max

[Max]

That's not what I meant.
Monitor the TX signal on channel 1 of the scope, and the RX signal on channel 2. Then measure the phase-shift between the two.

Hi,
oh sorry... yes right could be important to compare.

I've done already some time ago and read RX signal some few degrees ahead +3 or +4° (probably due to shield) respect to TX... or well... now I remember that's so... I don't used much care measuring it cause coils worked really good.

Best regards,
Max

[Qiaozhi]

Hi,
yes could be... but I've made my large coil using his data... getting just 90Hz difference at TX freq. All really closed I think to his coils.

That's why I think could be a components problem.

Kind regards,
Max

That's not what I meant.
Monitor the TX signal on channel 1 of the scope, and the RX signal on channel 2. Then measure the phase-shift between the two.

[Qiaozhi]

Hi Qiaozhi and all,
I'm reading the George Payne's article... JC1 posted the link yesterday.

Found all very interesting... maybe I've read before... don't remember now.

Anyway, my problem now is on conventions

I mean in the Payne's article I read that ferrite rod gives "zero" point... ok... then I've looked again at an old patent of Jack Gifford and he said that pure mineral give RX shift of -90° : all fine, I remember this also.

But then Payne call it zero and Gifford -90° (referred to the osc signal).

I think that -90° is the right way... of saying that thing...

Then Payne wrote that normal ground could fall between 0° and -5° of shift... so more negative of ferrite imposed shift.

QUESTION IS: that means soil could give a shift from -90° to -95° or from -90° to -85° ???????

Kind regards,
Max

Yes - there's a lot of confusion here, and I think it's done on purpose.
It appears to me that it really depends on where you place your reference point. Also, there is an assumption that these values represent the actual phase-shift produced by the various targets. In reality they seem to be the value of the phase-shift required to reject the particular target, and will once again depend where you set your reference point.

For example, first set up your detector to reject iron. i.e. with the sample pulse for the DISC channel located at the peak of the RX signal. Note this position. Then rotate the DISC control until you can just reject a pulltab. Measure the phase shift between the two positions. I expect you will find it is somewhere between 80 and 110 degrees, depending on the type of pulltab. This matches Gifford's patent.

Also, in the patent, minerals are shown at -90. This refers to the mineral sample point (phase "X") and does not literally mean "minerals". To discriminate against mineralized soil (i.e. contains some iron) we would need to add up to 5 degrees, and -90 +5 = -85 degrees. But again, this is somewhat confusing, because we really need to adjust the GEB channel to ignore mineralized soil, not the DISC channel. In this case, we need to subtract 5 degrees.

You just need to make yourself a coffee, and draw a few diagrams to get your head around this. And (of course) do some scope measurements on the circuit.

[Max]

The difference is probably in the coils, as you have made your own. Do you both have the same phase shift between the RX and TX signals?

Hi,
yes could be... but I've made my large coil using his data... getting just 90Hz difference at TX freq. All really closed I think to his coils.

That's why I think could be a components problem.

Kind regards,
Max

[Qiaozhi]

- sens at max
- disc at min
- notch pot at min
- notch off

Huh! When i adjust:
- sens at max
- disc at min
I'll get bedlam of bleeps!!! Usually no bleeps if Sens at "6" and Disc at "2", if we consider pot scale as from "0" to "10"...
So!? If these works for you, than something is much different between my and your detector? What?
I had Minelab Musketeer Advantage on service last month. After fixing minor problem i tested it. Behavior was simillar to my TGSL. When Sense on it adjusted over "7" Minelab start screaming, Disc level hadnt influence...
So i thought it was normal...
What should be the problem here?!
Huh!

The difference is probably in the coils, as you have made your own. Do you both have the same phase shift between the RX and TX signals?