TESORO GOLDEN SABRE

[Max]

The reason for the circuit?
Answer (with a question): How are you going to measure the frequency if you don't have an oscillator?

Hi,
right. But he could use the TX osc of GSabre... same thing...
just the formula is a bit more complex and have to know exactly values of two capacitors.

But he could do also that way, without making the oscillator circuit I posted.
Problem is that he hasn't :

- frequency meters
- inductance meters

But want to know inductance...
Really tricky thing without the two of above !

I think your advice of getting an inductance meter is the best for him.

Kind regards,
Max

[tiktak]

Hi,

Hi,
Max.
I still dont have one,but tomorrow will buy.I can aford only cheep one so far with only frequency reading!
I will use your chematic!

p.s.for the battery charger will be fine to use 20 ohm insted of 18 ohm or it will be no good?

[Max]

Desperate's Inductance Meter (adapter)

Hi tiktak,
ehm... don't know if it's woth or not...
maybe is much better buy one already made and good...
anyway, there is an ancient poptronics project

Can measure from 3uH to 7mH inductances (with poor precision...) using a multimeter with just a 200mV range.

You haven't buy anything new I think.

Not too bad... considering that 7mH are just the limit you need to measure Tesoro's coils.

Anyway... don't tell around I've posted that stuff.

Kind regards,
Max

[Max]

Hi,
Max.
I still dont have one,but tomorrow will buy.I can aford only cheep one so far with only frequency reading!
I will use your chematic!

p.s.for the battery charger will be fine to use 20 ohm insted of 18 ohm or it will be no good?

Take a look at the other circuit from poptronics.
20ohm would be fine for charger.

[tiktak]

hi,

I am planing to buy multimeter wiht frequency.
And find someone that have LC meter to borrow because I have some financial difficulties now.
Thanks


p.s.But if I have multimeter wiht frequency reading I can use this circuit and calculate inductance!This will be my goal now!

Frequency should be 14 Hz right?But still cant find your post for inductance!

[tiktak]

Hi,

This is very good!
But I need new multimeter any way!
You have help me very much.I have two days to make proper coil.Because my vacantion start and I will have to use my toy insted of TGS if I dont have working coil!
Thanks

p.s.have you tested this homemade LC meter?

[Max]

This is very good!
But I need new multimeter any way!
You have help me very much.I have two days to make proper coil.Because my vacantion start and I will have to use my toy insted of TGS if I dont have working coil!
Thanks

p.s.have you tested this homemade LC meter?

Hi,
no I haven't but I think it works. Was a great lecture this poptronics at that time... who knows ? maybe is better than many commercial low-quality L-meters.

Anyway,
about inductances look here:

http://geotech.thunting.com/cgi-bin/...oils/index.dat

You'll find everything about Tesoro's coils.

Kind regards,
Max

[tiktak]

Hi,

Hi,
Max.
I will buy tomorrow the parts for this circuit and plan to build it soon!
And also will search for some multimeter that have frequency reading!/and that I can aford/

And will contact you again!Please calculate the number of turns for this DD25cm coil that I asked you when have some free time!

p.s.I saw that you advice someone to try:

For DD you could try:
RX 130 turns suitable former to get a 22cm halve
TX 120 turns idem
wire 0.30 mm (free of varnish)

what is this DD 40?/22cm halve?/
I will check again the TGS theme to see what is the inductance for its coil!

[tiktak]

Hi,

in this link that you give there is no GS!!!

[Max]

in this link that you give there is no GS!!!

Hi,
of course there isn't.

These are tesoro's coils data. All uMax series coils fit GoldenSabre needs.

Do you see 9x8... well GoldenSabre was selled with that kind of coil.
Of course you can mount a concentric round e.g. the 8'' brown.
The big DD11'' too even if it has a bit different values, of course.

TX inductance is about 5.7 mH, RX a bit more 6.2 mH for all them.

Look also at resistances... 17. something is the minumum.

All these you can use on GoldenSabre.
Some are concentric coplanar (most of them)
That are more difficault to do respect to DD coils.

Anyway, you have to match about those inductances values to get it work good, with any kind of coil (DD, concentric coplanar, OO, whatever...).

Green are good values for GSabre. (LOBO used other values as standard, run on different frequencies)

Kind regards,
Max

[Max]

Hi,
Max.
I will buy tomorrow the parts for this circuit and plan to build it soon!
And also will search for some multimeter that have frequency reading!/and that I can aford/

And will contact you again!Please calculate the number of turns for this DD25cm coil that I asked you when have some free time!

p.s.I saw that you advice someone to try:

For DD you could try:
RX 130 turns suitable former to get a 22cm halve
TX 120 turns idem
wire 0.30 mm (free of varnish)

what is this DD 40?/22cm halve?/
I will check again the TGS theme to see what is the inductance for its coil!

DD40 ??? No, no.
I made DD22. "22cm halve" means one "half" of coil, D shaped... so the wounding of tx coil or rx coil.

Not that the former is 22cm diameter (is about 19cm)... or other things.

0.30 without varnish is too far from what you need.
I've used but changed caps on bandidoII to get it work good.
Then you have to use 0.25mm (30AWG) , without varnish, to avoid other troubles.

Kind regards,
Max

[tiktak]

Hi,
Max.
Thanks again!My mistake!

But can you tell me what is this 9X8 and 12X10 in cm-s?
Are they DD?

I will use 0,25 without the varnish!

Which is yours 22 DD?

Look at this DD11 why RX have less inductance and resistance from TX?
Shouldn't they be reverced?This DD 11 in inch must mean 27cm?/1 inch=2,5cm/

[Max]

Thanks Max
Ok, yes you are rigth, i was thinking on doing a smaller coil like a 16 cm one. I also have modified a comercial nails finder to run like a pinpointer, wich let me found a 11 mm coin at about 2 cms deep.
About no motion detector, yes, this TGS i think will do the job for getting the targer and for fine detection i ll use my pinponter. Also on my arsenal i m planing to carry my Clone PI MD. For this detector i m bulding a smaller coil to detect the smallest nugget i can. Who knows, if all this work, i ll be more satisfy of my homebrew projects.
One more question i forgot to ask. Changing the frequency by changing the inductance on tx coil, how is the tolerence of frequency range. I mean, if i set up the detector for 14 Khz i know i m on the correct performance, but if for example change the frequency to run it at 20 khz, will performance by reduced or not?

Best regards

Nelson

Hi Nelson,
remember now I have to answer your question !

" mean, if i set up the detector for 14 Khz i know i m on the correct performance, but if for example change the frequency to run it at 20 khz, will performance by reduced or not?"

Very good question.

If you run it out-frequency you could gain or lose.
Lets explain.
If you use e.g. a too lower frequency you'll have surely problems.
Example : TX f = 5Khz
your voltage converter run at f/2 = 2.5KHz

No way. You'll lose all your negative rail voltage that way. f too low.

Example : f=10Khz
Could work fine. BandidoII runs at 10KHz...
problem is always related to voltage converter output... but I think you'll get something from -2V to -2.5V that way and maybe changing some IC for less wasting current devices (e.g. TLC2262, MC33178 and the like).
Could work, you'll have maybe less performance cause of less voltage on coil... but could work even good.

Much better I think at 12KHz or 12.5Khz... very good freq. here. (have to try ).

Now more f
Example : 20Khz... uhm
You don't have problems on voltage converter that way (runs at 10Khz) BUT... 20Khz on the TX coil... uhm far above expected frequency e.g. for preamp up... maybe is better using the 5pF cap that time on LF353.

But it could work.

The big question is why changing freq ???

ANSWER ARE: SKIN EFFECT AND SMALL TARGETS

Higher frequencies are good for small items detection... cause even small things develop much eddy currents at higher frequencies... BUT there is a BIG (or depends... could be ENORMOUS) problem... FOIL.

FOIL IS ADDICTED TO HIGHER FREQS... also your shield would develop much more eddy currents at higher freqs... but that's not the real problem... I think that here isn't worth using e.g. 20KHz at tx osc... pay now or pay later on the search field...

But if you have clear and "easy soil" searchfield... why not.
Some soils are less easy at higher freqs... I know very well.

You have to consider also that GSabre parts are designed to run at that 14Khz ...of course can work at other freqs... but you can pay somewhere in the circuit if don't mod. some bit parts. Critical parts are preamp, sampler/integrators and voltage converter.

I think that good range to try freq. mods is 14KHz +/- 2.5Khz

Best regards,
Max

[tiktak]

hi

HI,
MAX.
Its look like I haven't understand you buy former I mean the thing that I wind the windings on and according to your last post you mean coil housing???
Please make this clear too.
I now that its stupid but I wanna be well prepared.And make no or minimum mistakes!
Thanks

[Max]

HI,
MAX.
Its look like I haven't understand you buy former I mean the thing that I wind the windings on and according to your last post you mean coil housing???
Please make this clear too.
I now that its stupid but I wanna be well prepared.And make no or minimum mistakes!
Thanks

Hi tiktak,
my friend what a confusion !

Coil housing... is coil housing, you need it to seal the coil... connect to the pole... etc mechanical stuff.

Coil housing is not the FORMER.

FORMER IS THE FORMER.

I mean... if I say I've used 19cm diameter former I mean something round (nails pattern, L-hooks on a wood table, a coke-can...well ehm it's not 19cms but is round...) to wound the coil... just this.

Former is something upon which you wound wire. Nothing else.

Then you shape your wound as a D... null etc... then seal everything in the Coil Housing.

It's clear now ?

Kind regards,
Max