TESORO GOLDEN SABRE

[tiktak]

Hi

Hi,
Ivconic and Max.
Very interesting talks here indeed!!!
I noticed that too!But haven't scope to check.And dont now for what to look.
Only think that I can say is that the coils with weeker audio are deeper!And loud are unstabile.I look for midle so far.

[amtech2005]

TESORO GOLDEN SABRE

CAN YOU PUT A DUMMY LOAD IN PLACE OF THE SEARCH-COIL TO DETERMINE IF THE NOISE IS CREATED BY THE SEARCH COIL OR IF OSCILLATIONS ARE ORIGINATING ON GOLDEN SABRES CIRCUIT BOARD. CAN YOU USE A RESISTIVE LOAD FIRST , SET UP YOUR STAGES , THEN HOOK-UP A INDUCTIVE LOAD ????? TAKE CARE....................EUGENE

[scevlik]

Hi,
Almost.
If you ask more people here they will tell you so but decide for your self what is the best way for you.
I null according Ivcoics advice.Disconect RX from TGS and conect to multimeter in ACV mode.
I achived this only with badmultimeter!You have scope................
So have no more to say here.
Null to 0.001 not to 0.000000000 there is no such!Only your instrument dont read it!But try this.
Good Luck

Hi

I nulled my coil but the results are same 18cm to 30mm coin,and very sensitive to motion.

[tiktak]

HI,

Hi,
Dont wory.If the device is working fine than you have to make another coil!
Or try to match the capacitator at RX.
Be pasient and you will be there soon.
I have the same probleme.And solved it with my 3 coil.
Which coil did you make?22 or 27?
I adicve you to try first 22.Because the things are easyer.
See you soon.

[tiktak]

Hi

Hi,
Ivconic.Max how are you?
I have just finish my next TGS.Better looking one.I have tryed some replacements.But have the same probleme as in begining.Constand loud scream.Maybe because I use MPSA14 now.Its louder.I have tryed to turn MPSA 14,nothing only some decriese in volume level.So it must be this 2n2222 again.I solder the pins like on my working device,but its look like this 2n2222 are different or I have other new probleme with same indications.
My PCB is not cleaned yet maybe this is the probleme but I dont think so.
Hope solve this soon.
And I will be able to post some good photos here.
Thanks

[tiktak]

Hi,

Hi,
Max.
I have experianced big nightmare!
Because I have similar problems with my first TGS,I used the same steps!
Cleaned well!And try to locate the source of the probleme!I have desolder again the LF358 then the sound stop!Afther this there is very week almost herable sound!With this IC off!Is this mean that my probleme is in batt checK?
Please help here.
I have played with 2N2222!Twist them in any posible way!Have changed all BC517,MPSA14;both 2N2222 no metter that they were brand new!
No point!But now I noticed that my BC517 is heating.But its fitted like on my first TGS.What the hell is goin on here?Cheking all day.Its look like there are no mistakes.Once I have managet to get some kind of reaction to hugh metal but now scream constant again and heating?How is this posible?
Thanks.
p.s.any new finds?

[Molzar]

Tesoro 10.5" Coil

Lately obtained used Tesoro 10.5" inch concentric coil. Suppose to be land base coil, I see old Tesoro manuals offer this coil as accessoroy. Don't see it on their website anymore, only 10.5" for Tiger Shark. Could be same as Tiger Shark? operates at 12.5KHz. anybody know?

Hooked this baby up my TGS lastnight, with OK result ~28cm in air on 2cm silver coin.

Some instability in All Metal. Discrimination mode rock solid in max sense.

Did tests on coil specs today.

Tx = 23.51 ohms, 5.49 mH, Q = 1.47
Rx = 22.63 ohms, 6.19 mH, Q= 1.72

Will do more tests later....


Molzar

[tiktak]

Hi

Hi,
Ineresting.
We asumed here 14kHz for optimal!
So strange if TGS work fine in such wide area?
But what is best here?

[Max]

Hi,
Max.
I have experianced big nightmare!
Because I have similar problems with my first TGS,I used the same steps!
Cleaned well!And try to locate the source of the probleme!I have desolder again the LF358 then the sound stop!Afther this there is very week almost herable sound!With this IC off!Is this mean that my probleme is in batt checK?
Please help here.
I have played with 2N2222!Twist them in any posible way!Have changed all BC517,MPSA14;both 2N2222 no metter that they were brand new!
No point!But now I noticed that my BC517 is heating.But its fitted like on my first TGS.What the hell is goin on here?Cheking all day.Its look like there are no mistakes.Once I have managet to get some kind of reaction to hugh metal but now scream constant again and heating?How is this posible?
Thanks.
p.s.any new finds?

Hi,

have you checked for voltages ? what about negative rail ?

try to pull out the fet at battery checker to see if change something... maybe the problem is there.

But this will be a problem just if op amp there is going to zero at output... so if battery stay at around 8volts... and I think it isn't, right ?

Check fet terminals, if different from your previous too.

Let me know...

Kind regards,
Max

[Molzar]

Hi,
Ineresting.
We asumed here 14kHz for optimal!
So strange if TGS work fine in such wide area?
But what is best here?

Tiger Sharks operate Freq is 12.5kHz, not sure if this is same coil as one for Tiger Shark (that why I ask), suppose to be old land based coil.

Freq when hooked to my TGS is ~ 14.5kHz.

Molzar

[tiktak]

Hi,

Hi,
Max.
Thanks for the fast reply!
I will check all!The fets are the same as on my previous device BF245C.
I am using test coil,so maybe this is the probleme!
Yesterday I have played again with device.I were prety shore that I have burned something.But I found point where I have responce to hugh metal so.............
What could be the probleme there?I will serch buy your leads.
p.s.the main probleme is that this LM358 near BC517 is heating and bc517 too.When I turn on.But some times they dont.Realy confused here.
I cheked the voltages just to make shore there is power and I think they were ok!But dont remember exact values.Will chek again and tell you.
Thanks.
The strangest thing is that I dont have same batt check like on first device!Now its have different voice.I use same parts.And some time batt chek dont stop at all,other time dont sound at all??

[Max]

Hi,
Max.
Thanks for the fast reply!
I will check all!The fets are the same as on my previous device BF245C.
I am using test coil,so maybe this is the probleme!
Yesterday I have played again with device.I were prety shore that I have burned something.But I found point where I have responce to hugh metal so.............
What could be the probleme there?I will serch buy your leads.
p.s.the main probleme is that this LM358 near BC517 is heating and bc517 too.When I turn on.But some times they dont.Realy confused here.
I cheked the voltages just to make shore there is power and I think they were ok!But dont remember exact values.Will chek again and tell you.
Thanks.
The strangest thing is that I dont have same batt check like on first device!Now its have different voice.I use same parts.And some time batt chek dont stop at all,other time dont sound at all??

Hi,
look at the 10uF capacitor... it's new part or did you use some old one there ? If dryed it could expose bad ESR (equivalent series resistance) enough to make your fet there stay sometimes/always on or off and thus giving confusing behaviour.

The fact 517 is running hot depends on fact it stay on for too long time... and current there flow, as it should, hi cause of driving the speaker. To reduce the problem mount a smaller speaker as temporary with say something 25-50 ohm impedance (some scraped from an old headset/headphones could be ok)... this way you'll save the 517 from thermal runaway when still trying to understand where problem is.

The LM358 hot seems, instead, a bad sign... probably means device is burnt already : look carefully at tracks for small solder joints or "ball" between legs if any. If you'll find fault there it's probable you need a new LM358 to replace the damaged.

Kind regards,
Max

[tiktak]

Hi

Hi,
Max.
I am using only brand new parts!
But I have went today and buy all again.This time I found 10mTANT and metal case 2N2222!
When cheanged all looks cool now NO heating! I probaly have turned 2N2222 wrong way and my PCB werent cleaned good!
Now BATT check is ok!I can detect metal very poor performance for now.But we will change this.The probleme is that there is constant week sound.More like treshold.But I dont here this on my first device!Why?
I am using now TL081 insteed of lm308 and TL082 insteed of TLC2262.
Can this be the source of this noise?Or its just bad coil?
Thanks for your help.

[Max]

Hi,
Max.
I am using only brand new parts!
But I have went today and buy all again.This time I found 10mTANT and metal case 2N2222!
When cheanged all looks cool now NO heating! I probaly have turned 2N2222 wrong way and my PCB werent cleaned good!
Now BATT check is ok!I can detect metal very poor performance for now.But we will change this.The probleme is that there is constant week sound.More like treshold.But I dont here this on my first device!Why?
I am using now TL081 insteed of lm308 and TL082 insteed of TLC2262.
Can this be the source of this noise?Or its just bad coil?
Thanks for your help.

Hi,
sure new parts... are better, but there's a problem with new parts also... so when I say "old" this would mean different things: some shops and dealers buy e.g. electrolitic capacitors in huge stocks (thousands of them all same value) and this just with slow process... that sometimes require also 10years from one order to the other...

If so... you buy "new" parts (at least you think so) but then the seller give actually you a 10years old product (yes, could happen easy in some places... and with some dealers...expecially when you find this stuff at very attractive prices...). Since ESR and drying don't know the difference between staying on the shelf or not... BUT knows very well that time goes by... you could buy "new" stuff with fairly low ESR.

Also... if you live in an hot place or really humid in some part of the year you could be sure , unless you buy stuff really made in around 1 year before not more, you got degradated ESR parts.

This was a cause of lot of troubles in old CRT TV sets (and also some newer) cause people sometimes don't have enough understanding of what's an electrolitic cap and that they MUST avoid putting TV in the kitchen or bathroom to keep working the TV and avoid rapid ESR derating...

Now cause some dealers are like users that put TV in the bathrooms... you can be sure you could buy bad caps, even "new", from them...

Anyway... the threshold sound you hear is strange too... try swap op amps starting at audio section and see what happens...

Kind regards,
Max

[tiktak]

HI,

Hi,
Ok.
Max I will try!But what you mean buy swap?Change new with NEW?
Right?
Thanks for Help