TESORO GOLDEN SABRE

[nelson]

Max, the only replacement i have done is LM308 by TL081, the rest is original from the schematics, perhapf a few caps that are from diferent materials.
Regards
Nelson

Hi Nelson,
I've tested untill now:

TL062
TL072
TL082
TLC2262

First 3 almost the same... changes nothing... well 062 is a bit more unstable than others two (that seem exactly the same, can't note any difference) but really few. All they are from STMicro.

Then also used TLC2262 and things are more stable, I've admit.

TLC2262 is from Texas Instruments. Have better noise figure. Same pinout of TL062.

I saw LF442 on original schematic so changed that thing to figure out how to suit better. If you have LF442 try this, or buy TLC2262.

"This cause i have the same problem with a few crack on audio"

To me happened just at maximum sens in all-metal.

This fact could depend also by other things... not just less noise in TL062 place. For example another hot spot here is preamplifier:

I've used LF353 but tested TL082, TLC2262 also here... but there are problems cause 353 has real particular jfet inputs... so it's a bit critical to change and save performance.

BTW have you used BF245C ?

Best regards,
Max

[detectoman]

nelson;

el flux son los residuos de pasta o fundente que queda al soldar
y que en algunos circuitos pudiera ser un causador de interferencias
y por eso ayudaria el quitarlo

un abrazo nelson
detectoman

[Max]

Hi,
Max.
I personaly remouved flux with sharp ithem and make shore that there have no connection betwen the elements.Is this good?
I still cant get good results!
I desided to use wire from my first coil/because now dont have other wire/
And use small d!
But wondering which to use?
I have several configurations that I can see here for DD 22 cm!
Which to use?
DD22 cm:
Former d=?
Outer d=?
Tx turns=?
Rx turns=?
wire 0,30 mm with varnish.
Thanks
p.s.I have used TL082 insted of LF353.Try TL072,but no differance.Now will order LF353.
But my probleme must be coil.
Thanks

Hi,
Try this:

OuterDD 22cm
Former diameter 19cm
wire as you said (that is about 0.28 without varnish)
TX turns = 140
RX turns = 145

About flux... never used a sharp tool to do that... always chemicals.
You maybe have removed main part of it... but this stuff is subtle and if you can, try use some cotton and one of solvents I've indicated (use outside).

About LF353 well there could be a problem... find it anyway and try in circuit, it's not so good replacement TL082 or TL072.

Some good replacement could be a dual CA series ic... now also obsolete, but with similar inputs circuitry. Have no idea at the moment of real good replacement for it.

Best regards,
Max

[Max]

Sorry for my poor english, what is flux?
Regards
Nelson

Hi Nelson,
flux is a kind of chemical stuff present in electronic solder wires.
Main purpose is removing superficial oxides (of copper, of components leads...) and so make it easy solder joints on PCBs.

You can also find it in cans... other containers and made of various chemicals, older flux was zinc-cloride based.

Activation of reaction is due by heat (soldering iron heat surfaces and flux) then flux bind oxigen (do you see fumes when solder stuff ?) thus giving e.g. polished copper layer, then lead-tin alloy solder easy surfaces.

When you use quality solder wire, with flux inside (so called "cored solder wire" or just "flux cored", most common is lead+tin+flux-core), you have a kind of residual of chemicals (residual flux) that seems like kind of "grease" near your solders.

That's the flux I mean, that you have to remove.

Other types of solder wire haven't flux inside and require external flux to make good solders (so called "solid solder wire", that often is just lead-tin alloy)

If you don't remove it you could have problems due to unwanted coupling between e.g. op. amps. cause flux is somehow conductive.

There are water soluble flux (like in some kester solder wires e.g. Kester Part # 24-6337-6409) that just require hot water to melt and dissolve from PCB in the water. But more often you have to use solvents to remove it as explained.

Best regards,
Max

[Max]

Max, the only replacement i have done is LM308 by TL081, the rest is original from the schematics, perhapf a few caps that are from diferent materials.
Regards
Nelson

Hi,
Ok, TL081 is fine for testing and even use... it's a good replacement for LM308 cause it's so easy to find.
Also detector is really stable with it in circuit: no problems.

You don't need change them to get it work good.

If you find there try TLC2262 instead of TL062.

Best regards,
Max

[tiktak]

Hi

Hi,
Try this:

OuterDD 22cm
Former diameter 19cm
wire as you said (that is about 0.28 without varnish)
TX turns = 140
RX turns = 145

About flux... never used a sharp tool to do that... always chemicals.
You maybe have removed main part of it... but this stuff is subtle and if you can, try use some cotton and one of solvents I've indicated (use outside).

About LF353 well there could be a problem... find it anyway and try in circuit, it's not so good replacement TL082 or TL072.

Some good replacement could be a dual CA series ic... now also obsolete, but with similar inputs circuitry. Have no idea at the moment of real good replacement for it.

Best regards,
Max

Hi,
Max.
Can you tell me what is this distance in cm-s for my DD 22 coil?
Shell I use this angles that ivconic shows on this pictures,or the shape of coils should be D?
Thanks
p.s.Can I try washing my pcb with thinner for nitrocellulose?

[tiktak]

did you wind Tx and Rx in same direction or they should have oposite directions?

[Max]

Hi,
Max.
Can you tell me what is this distance in cm-s for my DD 22 coil?
Shell I use this angles that ivconic shows on this pictures,or the shape of coils should be D?
Thanks
p.s.Can I try washing my pcb with thinner for nitrocellulose?

Hi tiktak,
picture posted is right for you. You can follow as guide , no need of perfect D at all. Then null as always.

About thinner for nitrocellulose... well I think it's not a good idea... cause maybe there is some other stuff in the mix. Don't know... if you can find e.g. pure acetone or isopropilic alcohol is better, also your thinner could leave residuals. No way.

You could try also with pure ethanol (but is less efficient removing flux) or ethilic ether (but do not breath it, work outside, heavy toxic).

Best regards,
Max

[tiktak]

Hi

Thanks,
Max.
But I am wonderind how much should be the distance that I have draw on this picture!If the coils should be 22 cm when asembled then I think that this distance must be more than 9,5cm?For the high I now 22cm but how much should be this distance,so when asembed to be 22cm?
Maybe 10,5 cm or 11?

[nelson]

Excelent and detailed explanation about flux Max.
So, this weekend i ll remove it from my pcb. The only think that i miss is the solvent name to remove it or may be i can do it just by removing flux from copper tracks, by scraching flux with a smal dentist tool.

Regards

Nelson

Hi Nelson,
flux is a kind of chemical stuff present in electronic solder wires.
Main purpose is removing superficial oxides (of copper, of components leads...) and so make it easy solder joints on PCBs.

You can also find it in cans... other containers and made of various chemicals, older flux was zinc-cloride based.

Activation of reaction is due by heat (soldering iron heat surfaces and flux) then flux bind oxigen (do you see fumes when solder stuff ?) thus giving e.g. polished copper layer, then lead-tin alloy solder easy surfaces.

When you use quality solder wire, with flux inside (so called "cored solder wire" or just "flux cored", most common is lead+tin+flux-core), you have a kind of residual of chemicals (residual flux) that seems like kind of "grease" near your solders.

That's the flux I mean, that you have to remove.

Other types of solder wire haven't flux inside and require external flux to make good solders (so called "solid solder wire", that often is just lead-tin alloy)

If you don't remove it you could have problems due to unwanted coupling between e.g. op. amps. cause flux is somehow conductive.

There are water soluble flux (like in some kester solder wires e.g. Kester Part # 24-6337-6409) that just require hot water to melt and dissolve from PCB in the water. But more often you have to use solvents to remove it as explained.

Best regards,
Max

[nelson]

Max , forget the previus post, here you just placed the answer about flux removers.
Regards

Nelson

Hi tiktak,
picture posted is right for you. You can follow as guide , no need of perfect D at all. Then null as always.

About thinner for nitrocellulose... well I think it's not a good idea... cause maybe there is some other stuff in the mix. Don't know... if you can find e.g. pure acetone or isopropilic alcohol is better, also your thinner could leave residuals. No way.

You could try also with pure ethanol (but is less efficient removing flux) or ethilic ether (but do not breath it, work outside, heavy toxic).

Best regards,
Max

[tiktak]

Nelson,
What is this distance that you use/look at the picture in my previous post!/for your DD 22 coil?
How is this new coil that you made preformance?
Tks

[Max]

Nelson,
What is this distance that you use/look at the picture in my previous post!/for your DD 22 coil?
How is this new coil that you made preformance?
Tks

Hi tiktak,
follow my instructions... I get 27cm steady for 1 eur coin with my DD22. Very stable performances, very stable detector operations, no hums, nothing at all now. Used TLC2262 instead of TL062.
Find the damn LF353, other things work (e.g. TL072) but 353 is better there, till now.

Tested in all-metal and disc, noticed that in disc I lose about 1cm... due maybe to pot setting... have no time to play with now.
In disc mode it rejects nails and even hammers !

It's a damn good detector, great disc, great stability. I think that with some mods I can beat bandidoII soon even on depth sector.

Sound is like bandidoII: weak, used also 16ohm speaker... no good.

Need to test something else... I have 566 maybe I'll try Ivconic's mod.

My problem is time!

Kind regards,
Max

[tiktak]

Hi

Hi,
Max.
I will listen to you.
And understand and I have no time lately.
I am agree that this is very good detector.I have played with old coil and I was able to discriminate al foil very easy.
Very promising.
I will try this coil now and tell you waht happens.
Can you please change 353 with TL072 or/and TL082 please and tell me the differance in depth?
I will be very happy.
But I doubt that you will have time to do this but still hoppe......
Thanks

[Max]

Hi,
Max.
I will listen to you.
And understand and I have no time lately.
I am agree that this is very good detector.I have played with old coil and I was able to discriminate al foil very easy.
Very promising.
I will try this coil now and tell you waht happens.
Can you please change 353 with TL072 or/and TL082 please and tell me the differance in depth?
I will be very happy.
But I doubt that you will have time to do this but still hoppe......
Thanks

Already tested:
lose 4-5cms