TESORO GOLDEN SABRE

[tiktak]

Hi,

Hi,
Thanks porkluvr!!
I am glad you help me.Unfortunatly they can send 2,500 pieces minimum!
But anyway thanks!
Isnt there any more easy to find good replacement?

[porkluvr]

supplier?

Hello Tiktak -----

I don't know where you are located but Digikey evidently has a multinational presence. They might be able to ship to you.
You might give them a try for TLC2262.

http://search.live.com/results.aspx?srch=105&FORM=AS5&q=digikey

[tiktak]

Hi,

Hi,
Max.
I try but cant find right solution with this calculator....................
Its look like its for oo coils?
Please advice me.How much turns for this DD25cm./inner diameter 25cm/

And one more thing:
I have this multimeter.I cant null my coil with this right?
ACV:0-200V-600V±1.2%
RANGE 100mV-700V AC;

I see that Ivconic use VC9805A.
I will search for something according my poket.
THANKS

[nelson]

Thanks Max.
Ok i ll do all that and see whats happend.

With the 15nF cap on RX coil leads, i got much sensitivity, but i also notice that on discrination, my wedding ring has almost no detction at minimum setting, while without the 15nF cap i get less sensitivity and my gold ring is detected at half turn on discrimination mode.

Perhaps all this, what else i can check to get more sensitivity. I ask this, cause you did 27 cm with 22 cms coil or this is ok. May be i need to check the TX stage to get more power, what do you think?
Another question, changing the TX coil inductance, changes the frequency too?
Do you have any formula to calculate the resonant frequency for the coil?

Regards

Nelson

Hi Nelson,
you can use a cat5 stp cable (the one used in ethernet works, flexible) to make internal connection from board to the panel connector. Other shielded cables are fine too... e.g. two pieces of RG-58 and the like or also some quality audio cables.
For coil cable you must use a shielded cable with at least 1 shield and two wires inside. You can use also e.g. 120cm of cat5 stp flexible. Only things needed are a good shield and low capacitance per lenght.

Is normal that when you touch leads unshielded you increase capacitance and so variation is seen by detector as a signal... you imbalance input stage that way. If use shielded cables the effect is reduced to minumum.

Another important thing is that cables must stay wounded e.g. on coil pole... expecially true for the lower end of them that goes to coil housing.

You have to avoid that cable moves during sweeping or you'll have a false signal from that movement relative to the coil.

Keep in mind that this is not a minelab/coiltek coil... where preamp is inside the potting at coil dish (but also minelab suggest to keep it fixed for similar reasons related to tx field radiation from cable). In our GSabre we have preamp on control unit... so also coil cable is "sensitive" to metal... not only the tx wire floating problem like in others...that's the clear reason of keeping it fixed to the pole.

Also in Tesoro' manuals there are instructions for that, in the assembly of detector part is explained how to wound coil cable to the lower end of pole.

1cm diameter 22cm depth ? I got about that too, maybe few more...
can't remember now.
Anyway, my reference is always 1eur coin... got something 27cm for that.

A better coil for detecting 1cm coin at good depth is maybe 25cm DD.
Think it could detect coin at 28-30 that way.

Think that I can reach BandidoII performance with some cap mod. and a bit of luck, have to find time!

Best regards,
Max

[Max]

How can I measure frequency?
I dont have mant tools.
I am entusiastet beginer,thats why its better for me to folow your leads and learn.

Hi,
replace TL062 with TL072 or TL082, cause they have less noise.
No big improvement but if you have them... why not ?
Same performance and less noise, good.

TL062 is a very obsolete product now... noisy. Can't do any good there.
That's my point of view.
Someone could say you that's good enough there... for my taste is too noisy.
Take you choice.

To measure frequency, well...
you need one of these things:
- scope
- frequency meter
- multimeter with frequency meter built-in (some have it and are cheapy)

(well there are other methods but these are direct and easy!)

First 2 are for a more advanced approach... as beginner I'll find a good multimeter capable of reading e.g. 200KHz or more, cheap stuff, good enough to understand what's going on at oscillator... you just need reading its frequency.

Or you could buy something e.g. on ebay... there are a lot of these instruments (scopes, meters...) for few us dollars there, and also quality ones.

Best regards,
Max

[tiktak]

Hi,

How can I measure frequency?
I dont have mant tools.
I am entusiastet beginer,thats why its better for me to folow your leads and learn.

[tiktak]

Hi,

Hi,
Max.
I now but dont trust myself because I do stupid mustakes!
Please calculate proper number of windings.You will make this coil anyway!
Thanks
p.s. Can't find TLC2262!!!
I dont now why?!??!?Should I change TL062 with TL072 or TL082 for now or this wont make any differance?
I now that become boring with all those questions but will find a way to ramach you somehow?
I am here until tuesday and then going for some field tests so have to make good coil!!
Can't wate to see how will this detector performe.

[Max]

A better coil for detecting 1cm coin at good depth is maybe 25cm DD.
Think it could detect coin at 28-30 that way.

Hi,
Max.
What you sugest?I just bought coil housing and ined diameter is 25cm!!
So will be glad to test this.But how much turns should be wounded for TX and RX?
I will have this 0,25 without the varnish wire in monday and will go buy some other multimeter that have 2v range and will try to make another coil.
Thanks

Hi tiktak,
I don't know how many turns it need ... have to calculate. You can do also using e.g. the posted coil calculator program. Then use 10-15% more turns and cut away turns till you match tx frequency.

Best regards,
Max

[tiktak]

Leto,
This LM388 can't be found!!!
I spend all day going to all the stores that I now to search for this with no results!!!
I see that LM390 is similar can it be used?
Or LM3900?

[tiktak]

Hi

A better coil for detecting 1cm coin at good depth is maybe 25cm DD.
Think it could detect coin at 28-30 that way.

Hi,
Max.
What you sugest?I just bought coil housing and ined diameter is 25cm!!
So will be glad to test this.But how much turns should be wounded for TX and RX?
I will have this 0,25 without the varnish wire in monday and will go buy some other multimeter that have 2v range and will try to make another coil.
Thanks

[Max]

Hi Max.

Can you help me with this:

1.- I made the coil you did (22 cms), and i obtained almost the same results has you (inductance, resistance and nulling).

2.- I got a few more cms by just adding a 10nF cap on rx coil leads.

3.- Now i m still having unstable sound that seems that the problem comes from the TX stage, cause when i put my hand or a coin very close to the wires that comes from the pcb, the detector sounds. Seems to me that i need to shield somethinf.
My RX anf TX leads that comes from the pcb to the chasis connector are 30AWG, same has used for the coil construction. These wires are about 3 to 5 cms long. So i was thinking on using shielded cable to run RF from tx and rx leads.

Any ideas Max?

Ohh i forgot, max detection on air for a 1 cm coin is just 22 cms, no more than that.

Regards
Nelson

Hi Nelson,
you can use a cat5 stp cable (the one used in ethernet works, flexible) to make internal connection from board to the panel connector. Other shielded cables are fine too... e.g. two pieces of RG-58 and the like or also some quality audio cables.
For coil cable you must use a shielded cable with at least 1 shield and two wires inside. You can use also e.g. 120cm of cat5 stp flexible. Only things needed are a good shield and low capacitance per lenght.

Is normal that when you touch leads unshielded you increase capacitance and so variation is seen by detector as a signal... you imbalance input stage that way. If use shielded cables the effect is reduced to minumum.

Another important thing is that cables must stay wounded e.g. on coil pole... expecially true for the lower end of them that goes to coil housing.

You have to avoid that cable moves during sweeping or you'll have a false signal from that movement relative to the coil.

Keep in mind that this is not a minelab/coiltek coil... where preamp is inside the potting at coil dish (but also minelab suggest to keep it fixed for similar reasons related to tx field radiation from cable). In our GSabre we have preamp on control unit... so also coil cable is "sensitive" to metal... not only the tx wire floating problem like in others...that's the clear reason of keeping it fixed to the pole.

Also in Tesoro' manuals there are instructions for that, in the assembly of detector part is explained how to wound coil cable to the lower end of pole.

1cm diameter 22cm depth ? I got about that too, maybe few more...
can't remember now.
Anyway, my reference is always 1eur coin... got something 27cm for that.

A better coil for detecting 1cm coin at good depth is maybe 25cm DD.
Think it could detect coin at 28-30 that way.

Think that I can reach BandidoII performance with some cap mod. and a bit of luck, have to find time!

Best regards,
Max

[nelson]

Hi Max.

Can you help me with this:

1.- I made the coil you did (22 cms), and i obtained almost the same results has you (inductance, resistance and nulling).

2.- I got a few more cms by just adding a 10nF cap on rx coil leads.

3.- Now i m still having unstable sound that seems that the problem comes from the TX stage, cause when i put my hand or a coin very close to the wires that comes from the pcb, the detector sounds. Seems to me that i need to shield somethinf.
My RX anf TX leads that comes from the pcb to the chasis connector are 30AWG, same has used for the coil construction. These wires are about 3 to 5 cms long. So i was thinking on using shielded cable to run RF from tx and rx leads.

Any ideas Max?

Ohh i forgot, max detection on air for a 1 cm coin is just 22 cms, no more than that.

Regards
Nelson

[Max]

Hi,
Max.
Have you tryed to replace TL062 with LF353?And if so what are the results?
Thanks

Hi,
no I use TLC2262 instead of TL062. More stable.

Best regards,
Max

[tiktak]

Hi,

Hi,
Max.
Have you tryed to replace TL062 with LF353?And if so what are the results?
Thanks

[Max]

Using my own calculator (see attached) I used 127mm inside radius, 0.27mm wire thickness and 117 turns. This gives an inductance of 8.98mH, which is closer to your measured result. How accurate is the value of the inner radius? This is a sensitive parameter, and only a few millimetres can change the inductance significantly. The calculator also shows a coil thickness of 5.62mm, whereas you have 5mm. Since the calculations assume a square cross-section to the coil, your's may be elongated.
Hope this helps.

By the way, Chinese multimeters can also be good.

Hi,
Yes that's true.
Is a matter of looking before buy...
I mean sometimes there are bad quality devices and also parts coming from there...and other country also... but I've found many useful things, stuff , tools, meters etc that are almost the same (in some cases even better) than hi-branded products... that at the end are about always made in China at now.

All big companies make there their products and then sell here with enormous bargains !

The only big difference sometimes is only the price !
Found great things that cost 1/10 or also 1/20 of BRANDED ones and work/are the same!

Kind regards,
Max