TESORO GOLDEN SABRE

[detectoman]

ivconic

thanks for attention to us
your work is excellent
one question please say me
these detector gold sabre is movement? or not movement?
can add big coil dd what is features
is superior in depht or discrimination to my, spectrum xlt?
is the show diagram early daytona' excellent and practique simplification of metal detector discrimination your opinion in function

best wises ivconic and nelson

detectoman

[ivconic]

Yes it is "movement" type of detector...or MOTION...
Daytona is simple yet very interesting..
Regards!

[Unregistered]

?

Hello,
MAX

For LM308 I suggest (but hard to find):
NTE398

Can I use LF398????
Will this be better than TL81 or its the same like NTE398?
And for LF353 you give TLC2262!
I can find Ka2262 and TEA2262!!

What will you advice me
THANKS

[Max]

Hello,
MAX

For LM308 I suggest (but hard to find):
NTE398

Can I use LF398????
Will this be better than TL81 or its the same like NTE398?
And for LF353 you give TLC2262!
I can find Ka2262 and TEA2262!!

What will you advice me
THANKS

Hi,
1. NO, LM398 is another thing (sample and hold IC) and you can't use there.
2. NO, they are different parts : ka2262 if FM demodulator pll; tea2262 is SWITCH MODE POWER SUPPLY CONTROLLER for TV/VCR sets.

Sorry, you can't. But you can try lm358/tl082 instead of 2262 and lf356/lf357 instead of lm308: they are very easy to find in europe and many other countries all around the world (are also obsolete parts but nevermind).

Best regards,
Max

[Unregistered]

?

Hi,
MAX!
isn't
LM308 single amplifer?It should be replaced whith TL081!!?!??!?
And for LF353-TL082-dual amplifer??!!?!?!?!?
Thanks

p.s NE5534 insted of LM308?




Hi,
1. NO, LM398 is another thing (sample and hold IC) and you can't use there.
2. NO, they are different parts : ka2262 if FM demodulator pll; tea2262 is SWITCH MODE POWER SUPPLY CONTROLLER for TV/VCR sets.

Sorry, you can't. But you can try lm358/tl082 instead of 2262 and lf356/lf357 instead of lm308: they are very easy to find in europe and many other countries all around the world (are also obsolete parts but nevermind).

Best regards,
Max

[nelson]

Hi Ivconic.
Yesterday i made the first coil. Before i place the electric tape it measured 6.5 mH and after a put the tape measured 6.85 mH and 12.3 ohms. Coil diameter is 19 cms and wire is 0.42 mm in diamater. My questión is if these values are accepted, because for the other coil i ll have to compensate the difference in mH. This means to made the coil for a value of 6 mH and after i place the electric tape should meassure 6.35 mH.
Or should i have to take of the electric tape to get the correct values of 6 and 6.5 mH?
REgards and thanks for your unconditional support.

Nelson

I'll try to prepare for tomorrow, if you are not in hurry...Dont have it prepared....I dont understand? It is so easy and clear..? Just obey schematic and trace pcb....For testing purposes you may omit "notch" and all arround it...Only disc./all metal switch is needed....Sens.pot and ON/Off switch...for disc and gnd may use trimmers while testing...
OK anyway i'll draw pic tomorrow...
Here is more details about coil...
regards

[Max]

Hi,
MAX!
isn't
LM308 single amplifer?It should be replaced whith TL081!!?!??!?
And for LF353-TL082-dual amplifer??!!?!?!?!?
Thanks

p.s NE5534 insted of LM308?




Hi,
1. NO, LM398 is another thing (sample and hold IC) and you can't use there.
2. NO, they are different parts : ka2262 if FM demodulator pll; tea2262 is SWITCH MODE POWER SUPPLY CONTROLLER for TV/VCR sets.

Sorry, you can't. But you can try lm358/tl082 instead of 2262 and lf356/lf357 instead of lm308: they are very easy to find in europe and many other countries all around the world (are also obsolete parts but nevermind).

Best regards,
Max

Hi,
yes 308 is single, could use tl081 and ne5534 would be even better (much less noise). They are both really easy to find.

LF353, TL082 are dual, you could think also at NE5532 (much less noise, dual version of 5534) but look at consumption ; 1 ne5532 needs about 6mA !
I've tested on bandido and WOW I need another power supply circuit to drive that stuff there (-V rail ran out of steam with these philips pearls)...so I've putted tlc2262 from TI that required much less current though mantaining about same noise level.
But for all the rest they are wonderful devices, I use a lot of them in audio stuff and other things and they rocks.

Best regards,
Max

[ivconic]

GS


Nelson, it is normal,inductance to raise a bit, when coil is "constrained" and
windings have less space between them. I also noticed that. Tape has nothing to
do with inductance changes...at least noticeable one.
6.85mH will work fine on G.Sabre. But i am concerned about resistivity...to low.
"...have to compensate the difference in mH...." No, no need for that.
"wire is 0.42 mm in diamater.." I think this is way to large. Better use 0.25mm.
or if cant find, than 0.3mm.
But since you already made it...it will be interested to test it, anyway.
Use that for TX and make another one with 0.3mm for RX...Try to keep resistance
over 18ohms....
I might be wrong on this, but my coils works vry good and resistances are over 18ohms,
also i used 0.25mm wire (0.28mm with varnish)...
Inductances are arround 6mH...more-less..
Regards!

[nelson]

Ok Ivconic, yes resistance is 12.3 ohms and i don´t know how to raice it. Should i use a resistor in series?
The low resistance, may be is for the wire diameter (to high).
I agree with you, experimenting is the clue.
Today i did`t have time to work on Golden Sabre. To much ofice work and i don`t know if tomorrow i ll have the time to do so. I m just wating next weekend to finish this MD and of course post results and expirencies with it.
Will keep on touch.
Best regards.
Nelson

Nelson, it is normal,inductance to raise a bit, when coil is "constrained" and
windings have less space between them. I also noticed that. Tape has nothing to
do with inductance changes...at least noticeable one.
6.85mH will work fine on G.Sabre. But i am concerned about resistivity...to low.
"...have to compensate the difference in mH...." No, no need for that.
"wire is 0.42 mm in diamater.." I think this is way to large. Better use 0.25mm.
or if cant find, than 0.3mm.
But since you already made it...it will be interested to test it, anyway.
Use that for TX and make another one with 0.3mm for RX...Try to keep resistance
over 18ohms....
I might be wrong on this, but my coils works vry good and resistances are over 18ohms,
also i used 0.25mm wire (0.28mm with varnish)...
Inductances are arround 6mH...more-less..
Regards!

[Max]

Ok Ivconic, yes resistance is 12.3 ohms and i don´t know how to raice it. Should i use a resistor in series?
The low resistance, may be is for the wire diameter (to high).
I agree with you, experimenting is the clue.
Today i did`t have time to work on Golden Sabre. To much ofice work and i don`t know if tomorrow i ll have the time to do so. I m just wating next weekend to finish this MD and of course post results and expirencies with it.
Will keep on touch.
Best regards.
Nelson

Hi Nelson,
ivconic is right, I have original coil and I see 22.6 ohm on tx and 23.2 ohm on rx.You need to rewind with a thinner wire.

Use some 30awg or european 0.25mm diameter. Find Mike's instructions on nulling the rx coil.

Best regards,
Max

[Unregistered]

To MAX

Hi,
MAX!
Then can I use LM108 or LF151 for LM308N?
I found LF153 for LF353!Its look like its even better!With high temperature stability!
What will you advice me??
THANKS

[robert]

???


Unregistered, you are real pain in the *** with all those questions about op-amps!!!
Are you that imbecile and idiot that can not find any proper datas on the .net?
I never saw most stupid man than you! Pain in the ***! Million same questions!

[nelson]

Ok Max, i ll do so, but tell me, if i rewind a smaller wire this will affect my inductance? ¿How may turns aproximate are needed to get the correct resistance? ¿Can i use a resistor for it?
What is the reason to get resistance value higer?
In advance many thanks Max
Nelson

Hi Nelson,
ivconic is right, I have original coil and I see 22.6 ohm on tx and 23.2 ohm on rx.You need to rewind with a thinner wire.

Use some 30awg or european 0.25mm diameter. Find Mike's instructions on nulling the rx coil.

Best regards,
Max

[Max]

Hi,
MAX!
Then can I use LM108 or LF151 for LM308N?
I found LF153 for LF353!Its look like its even better!With high temperature stability!
What will you advice me??
THANKS

Hi,
yes YOU CAN ! THEY ARE ! YOU WON !
1xx mean they have better specs so extended ranges. So keep them and solder that stuff before you'll change idea again!
(was a real pain )

Best regards,
Max

[Max]

Ok Max, i ll do so, but tell me, if i rewind a smaller wire this will affect my inductance? ¿How may turns aproximate are needed to get the correct resistance? ¿Can i use a resistor for it?
What is the reason to get resistance value higer?
In advance many thanks Max
Nelson

Hi Nelson,
you can't use resistor to get right value connected at pcb pads in a VLF. That way you lose current in your coils and add small instability due to resistor thermal variations, but most important you maybe can't get it oscillate on tx cause your impedance at coil could be wrong for stable operations.

NOTE:
You can use resistors e.g. in PIs detectors where you control the on switch by other timing circuits and so haven't a free running oscillator where the coil is a part of it; also in PI adding a series resistor to coil means cutting some current and so limiting battery drain, mosfet warming etc so in PI could be convenient having a resistor.

If you rewind with another thinner wire you have more inductance if other params remains the same, and also more resistance of winding.

As an example, do make a good DD with 22cm external diameter use that data:

wire from 0.25mm to 0.28mm external diameter ; you could use also 30AWG but but little mod on turns number are often required
I use :
TX 120 turns
RX 130 turns
resistance would be around 20 ohm , for both, or even more (22-24 ohm).

Good way to make coils is always wound about 10% more turns than extimated and then measure values reducing 1 or few turns step by step, till approaching what you need.

You could find more info about coplanar concentric in Emery's article, and info about tesoro's round conc coils on Mike's instructions (you can find in older threads about bandido and others)

You also need to null very well rx signal by moving on the overlapping area one or both coils. Use a scope, connect a 1k resistor and a capacitor like in rx stage in parallel with rx leads. You need reach under 3mV peak-to-peak, the lesser the better (I get 1mv pk-pk on my DD coil and works fine).

Having a too low resistance on e.g. tx coil in colpitts osc would mean have no oscillations at all or have with too hi distortion, so keep resistance hi enough to have good shape (perfect sinus) waves and stable operations.

Best regards,
Max